Merge pull request '[agent/codex:gpt-5.3-codex-spark] Read ~/spec/code/core/go/webview/RFC.md fully. Find features...' (#14) from agent/read---spec-code-core-go-webview-rfc-md into dev

Co-Authored-By: Virgil <virgil@lethean.io>

.core/build.yaml

@@ -0,0 +1,24 @@
+version: 1
+
+project:
+  name: go-webview
+  description: Chrome DevTools Protocol client
+  binary: ""
+
+build:
+  cgo: false
+  flags:
+    - -trimpath
+  ldflags:
+    - -s
+    - -w
+
+targets:
+  - os: linux
+    arch: amd64
+  - os: linux
+    arch: arm64
+  - os: darwin
+    arch: arm64
+  - os: windows
+    arch: amd64

.core/release.yaml

@@ -0,0 +1,20 @@
+version: 1
+
+project:
+  name: go-webview
+  repository: core/go-webview
+
+publishers: []
+
+changelog:
+  include:
+    - feat
+    - fix
+    - perf
+    - refactor
+  exclude:
+    - chore
+    - docs
+    - style
+    - test
+    - ci

.gitignore

@@ -0,0 +1,2 @@
+.core/
+.idea/

CLAUDE.md

@@ -1,33 +1,63 @@
 # CLAUDE.md
 
-Module: `forge.lthn.ai/core/go-webview` — Chrome DevTools Protocol client for browser automation.
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+Module: `dappco.re/go/core/webview` — Chrome DevTools Protocol client for browser automation.
 
 ## Commands
 
 ```bash
-go test ./...          # Run all tests (must pass before commit)
-go test -v -run Name   # Run a single test
-gofmt -w .             # Format code
+go test ./...                          # Run all tests (must pass before commit)
+go test -v -run TestActionSequence_Good ./...  # Run a single test
+gofmt -w .                             # Format code
+go vet ./...                           # Static analysis
 ```
 
+## Prerequisites
+
+Tests and usage require a running Chrome/Chromium with `--remote-debugging-port=9222`. The package does not launch Chrome itself. Verify with `curl http://localhost:9222/json`.
+
+```bash
+# macOS
+/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --remote-debugging-port=9222
+
+# Headless (CI)
+google-chrome --headless=new --remote-debugging-port=9222 --no-sandbox --disable-gpu
+```
+
+## Architecture
+
+```
+Application Code → Webview (high-level API) → CDPClient (WebSocket transport) → Chrome
+```
+
+Single flat package (`package webview`). No sub-packages.
+
+| File | Layer | Purpose |
+|------|-------|---------|
+| `cdp.go` | Transport | WebSocket connection, CDP message framing, event dispatch. No browser-level logic. |
+| `webview.go` | High-level API | Navigate, Click, Type, Screenshot, DOM queries, console capture. Application-facing. |
+| `actions.go` | Action system | `Action` interface + concrete types (ClickAction, TypeAction, etc.) + fluent `ActionSequence` builder. |
+| `console.go` | Diagnostics | `ConsoleWatcher` (filtered console capture) and `ExceptionWatcher` (JS exception tracking). |
+| `angular.go` | SPA helpers | Angular-specific: Zone.js stability, router navigation, component introspection, ngModel access. |
+
+Key patterns:
+- `CDPClient.Call(ctx, method, params)` sends a CDP command and blocks for the response via a pending-channel map.
+- Events flow from Chrome → `readLoop` goroutine → registered handlers (each dispatched in its own goroutine).
+- `Webview` enables `Runtime`, `Page`, and `DOM` CDP domains on construction; console capture starts immediately.
+- New action types: add struct + `Execute` method in `actions.go`, builder method on `ActionSequence`, `_Good` test.
+- New SPA framework helpers: create `<framework>.go` following the `angular.go` pattern.
+
 ## Coding Standards
 
-- UK English in all comments, docs, and commit messages
+- UK English in all comments, docs, and commit messages (behaviour, colour, initialise)
 - EUPL-1.2 licence header (`// SPDX-License-Identifier: EUPL-1.2`) in every Go file
-- Conventional commits: `type(scope): description`
+- Conventional commits: `type(scope): description` (scopes: cdp, angular, console, actions)
 - Co-author trailer on every commit: `Co-Authored-By: Virgil <virgil@lethean.io>`
 - Test naming: `_Good` (happy path), `_Bad` (expected errors), `_Ugly` (panics/edge cases)
-
-## Key API
-
-```go
-wv, err := webview.New(webview.WithDebugURL("http://localhost:9222"))
-defer wv.Close()
-wv.Navigate("https://example.com")
-wv.Click("#submit")
-wv.Type("#input", "text")
-screenshot, _ := wv.Screenshot()
-```
+- Standard `testing.T` only — no test frameworks
+- Wrap errors with `coreerr.E("Scope.Method", "description", err)` from `go-log`, never `fmt.Errorf`
+- Protect shared state with `sync.RWMutex`; copy handler slices before calling outside lock
 
 ## Docs
 

README.md

@@ -1,4 +1,4 @@
-[![Go Reference](https://pkg.go.dev/badge/forge.lthn.ai/core/go-webview.svg)](https://pkg.go.dev/forge.lthn.ai/core/go-webview)
+[![Go Reference](https://pkg.go.dev/badge/dappco.re/go/core/webview.svg)](https://pkg.go.dev/dappco.re/go/core/webview)
 [![License: EUPL-1.2](https://img.shields.io/badge/License-EUPL--1.2-blue.svg)](LICENSE.md)
 [![Go Version](https://img.shields.io/badge/Go-1.26-00ADD8?style=flat&logo=go)](go.mod)
 
@@ -6,14 +6,14 @@
 
 Chrome DevTools Protocol (CDP) client for browser automation, testing, and scraping. Connects to an externally managed Chrome or Chromium instance running with `--remote-debugging-port=9222`, providing navigation, DOM queries, click and type actions, console capture, JavaScript evaluation, screenshots, multi-tab support, viewport emulation, and a fluent `ActionSequence` builder. Includes Angular-specific helpers for Zone.js stability, router navigation, component introspection, and ngModel access.
 
-**Module**: `forge.lthn.ai/core/go-webview`
+**Module**: `dappco.re/go/core/webview`
 **Licence**: EUPL-1.2
 **Language**: Go 1.25
 
 ## Quick Start
 
 ```go
-import "forge.lthn.ai/core/go-webview"
+import "dappco.re/go/core/webview"
 
 wv, err := webview.New(webview.WithDebugURL("http://localhost:9222"))
 defer wv.Close()
@@ -34,6 +34,7 @@ err = webview.NewActionSequence().
 
 ## Documentation
 
+- [API Contract](docs/api-contract.md) — exported API inventory with signatures and current test coverage
 - [Architecture](docs/architecture.md) — CDP connection, DOM queries, console capture, Angular helpers, action system
 - [Development Guide](docs/development.md) — prerequisites, build, test patterns, adding actions
 - [Project History](docs/history.md) — completed phases, known limitations, future considerations

actions.go

@@ -1,9 +1,12 @@
+// SPDX-License-Identifier: EUPL-1.2
 package webview
 
 import (
 	"context"
-	"fmt"
 	"time"
+
+	core "dappco.re/go/core"
+	coreerr "dappco.re/go/core/log"
 )
 
 // Action represents a browser action that can be performed.
@@ -43,7 +46,7 @@ func (a NavigateAction) Execute(ctx context.Context, wv *Webview) error {
 		"url": a.URL,
 	})
 	if err != nil {
-		return fmt.Errorf("failed to navigate: %w", err)
+		return coreerr.E("NavigateAction.Execute", "failed to navigate", err)
 	}
 	return wv.waitForLoad(ctx)
 }
@@ -81,7 +84,7 @@ type ScrollAction struct {
 
 // Execute performs the scroll action.
 func (a ScrollAction) Execute(ctx context.Context, wv *Webview) error {
-	script := fmt.Sprintf("window.scrollTo(%d, %d)", a.X, a.Y)
+	script := core.Sprintf("window.scrollTo(%d, %d)", a.X, a.Y)
 	_, err := wv.evaluate(ctx, script)
 	return err
 }
@@ -93,7 +96,7 @@ type ScrollIntoViewAction struct {
 
 // Execute scrolls the element into view.
 func (a ScrollIntoViewAction) Execute(ctx context.Context, wv *Webview) error {
-	script := fmt.Sprintf("document.querySelector(%q)?.scrollIntoView({behavior: 'smooth', block: 'center'})", a.Selector)
+	script := core.Sprintf("document.querySelector(%q)?.scrollIntoView({behavior: 'smooth', block: 'center'})", a.Selector)
 	_, err := wv.evaluate(ctx, script)
 	return err
 }
@@ -105,7 +108,7 @@ type FocusAction struct {
 
 // Execute focuses the element.
 func (a FocusAction) Execute(ctx context.Context, wv *Webview) error {
-	script := fmt.Sprintf("document.querySelector(%q)?.focus()", a.Selector)
+	script := core.Sprintf("document.querySelector(%q)?.focus()", a.Selector)
 	_, err := wv.evaluate(ctx, script)
 	return err
 }
@@ -117,7 +120,7 @@ type BlurAction struct {
 
 // Execute removes focus from the element.
 func (a BlurAction) Execute(ctx context.Context, wv *Webview) error {
-	script := fmt.Sprintf("document.querySelector(%q)?.blur()", a.Selector)
+	script := core.Sprintf("document.querySelector(%q)?.blur()", a.Selector)
 	_, err := wv.evaluate(ctx, script)
 	return err
 }
@@ -129,7 +132,7 @@ type ClearAction struct {
 
 // Execute clears the input value.
 func (a ClearAction) Execute(ctx context.Context, wv *Webview) error {
-	script := fmt.Sprintf(`
+	script := core.Sprintf(`
 		const el = document.querySelector(%q);
 		if (el) {
 			el.value = '';
@@ -149,7 +152,7 @@ type SelectAction struct {
 
 // Execute selects the option.
 func (a SelectAction) Execute(ctx context.Context, wv *Webview) error {
-	script := fmt.Sprintf(`
+	script := core.Sprintf(`
 		const el = document.querySelector(%q);
 		if (el) {
 			el.value = %q;
@@ -168,7 +171,7 @@ type CheckAction struct {
 
 // Execute checks/unchecks the checkbox.
 func (a CheckAction) Execute(ctx context.Context, wv *Webview) error {
-	script := fmt.Sprintf(`
+	script := core.Sprintf(`
 		const el = document.querySelector(%q);
 		if (el && el.checked !== %t) {
 			el.click();
@@ -191,7 +194,7 @@ func (a HoverAction) Execute(ctx context.Context, wv *Webview) error {
 	}
 
 	if elem.BoundingBox == nil {
-		return fmt.Errorf("element has no bounding box")
+		return coreerr.E("HoverAction.Execute", "element has no bounding box", nil)
 	}
 
 	x := elem.BoundingBox.X + elem.BoundingBox.Width/2
@@ -219,7 +222,7 @@ func (a DoubleClickAction) Execute(ctx context.Context, wv *Webview) error {
 
 	if elem.BoundingBox == nil {
 		// Fallback to JavaScript
-		script := fmt.Sprintf(`
+		script := core.Sprintf(`
 			const el = document.querySelector(%q);
 			if (el) {
 				const event = new MouseEvent('dblclick', {bubbles: true, cancelable: true, view: window});
@@ -266,7 +269,7 @@ func (a RightClickAction) Execute(ctx context.Context, wv *Webview) error {
 
 	if elem.BoundingBox == nil {
 		// Fallback to JavaScript
-		script := fmt.Sprintf(`
+		script := core.Sprintf(`
 			const el = document.querySelector(%q);
 			if (el) {
 				const event = new MouseEvent('contextmenu', {bubbles: true, cancelable: true, view: window});
@@ -374,7 +377,7 @@ type SetAttributeAction struct {
 
 // Execute sets the attribute.
 func (a SetAttributeAction) Execute(ctx context.Context, wv *Webview) error {
-	script := fmt.Sprintf("document.querySelector(%q)?.setAttribute(%q, %q)", a.Selector, a.Attribute, a.Value)
+	script := core.Sprintf("document.querySelector(%q)?.setAttribute(%q, %q)", a.Selector, a.Attribute, a.Value)
 	_, err := wv.evaluate(ctx, script)
 	return err
 }
@@ -387,7 +390,7 @@ type RemoveAttributeAction struct {
 
 // Execute removes the attribute.
 func (a RemoveAttributeAction) Execute(ctx context.Context, wv *Webview) error {
-	script := fmt.Sprintf("document.querySelector(%q)?.removeAttribute(%q)", a.Selector, a.Attribute)
+	script := core.Sprintf("document.querySelector(%q)?.removeAttribute(%q)", a.Selector, a.Attribute)
 	_, err := wv.evaluate(ctx, script)
 	return err
 }
@@ -400,7 +403,7 @@ type SetValueAction struct {
 
 // Execute sets the value.
 func (a SetValueAction) Execute(ctx context.Context, wv *Webview) error {
-	script := fmt.Sprintf(`
+	script := core.Sprintf(`
 		const el = document.querySelector(%q);
 		if (el) {
 			el.value = %q;
@@ -459,7 +462,7 @@ func (s *ActionSequence) WaitForSelector(selector string) *ActionSequence {
 func (s *ActionSequence) Execute(ctx context.Context, wv *Webview) error {
 	for i, action := range s.actions {
 		if err := action.Execute(ctx, wv); err != nil {
-			return fmt.Errorf("action %d failed: %w", i, err)
+			return coreerr.E("ActionSequence.Execute", core.Sprintf("action %d failed", i), err)
 		}
 	}
 	return nil
@@ -492,18 +495,18 @@ func (wv *Webview) DragAndDrop(sourceSelector, targetSelector string) error {
 	// Get source and target elements
 	source, err := wv.querySelector(ctx, sourceSelector)
 	if err != nil {
-		return fmt.Errorf("source element not found: %w", err)
+		return coreerr.E("Webview.DragAndDrop", "source element not found", err)
 	}
 	if source.BoundingBox == nil {
-		return fmt.Errorf("source element has no bounding box")
+		return coreerr.E("Webview.DragAndDrop", "source element has no bounding box", nil)
 	}
 
 	target, err := wv.querySelector(ctx, targetSelector)
 	if err != nil {
-		return fmt.Errorf("target element not found: %w", err)
+		return coreerr.E("Webview.DragAndDrop", "target element not found", err)
 	}
 	if target.BoundingBox == nil {
-		return fmt.Errorf("target element has no bounding box")
+		return coreerr.E("Webview.DragAndDrop", "target element has no bounding box", nil)
 	}
 
 	// Calculate center points

angular.go

@@ -1,10 +1,12 @@
+// SPDX-License-Identifier: EUPL-1.2
 package webview
 
 import (
 	"context"
-	"fmt"
-	"strings"
 	"time"
+
+	core "dappco.re/go/core"
+	coreerr "dappco.re/go/core/log"
 )
 
 // AngularHelper provides Angular-specific testing utilities.
@@ -43,7 +45,7 @@ func (ah *AngularHelper) waitForAngular(ctx context.Context) error {
 		return err
 	}
 	if !isAngular {
-		return fmt.Errorf("not an Angular application")
+		return coreerr.E("AngularHelper.waitForAngular", "not an Angular application", nil)
 	}
 
 	// Wait for Zone.js stability
@@ -91,6 +93,21 @@ func (ah *AngularHelper) isAngularApp(ctx context.Context) (bool, error) {
 func (ah *AngularHelper) waitForZoneStability(ctx context.Context) error {
 	script := `
 		new Promise((resolve, reject) => {
+			const pollZone = () => {
+				if (!window.Zone || !window.Zone.current) {
+					resolve(true);
+					return;
+				}
+
+				const inner = window.Zone.current._inner || window.Zone.current;
+				if (!inner._hasPendingMicrotasks && !inner._hasPendingMacrotasks) {
+					resolve(true);
+					return;
+				}
+
+				setTimeout(pollZone, 50);
+			};
+
 			// Get the root elements
 			const roots = window.getAllAngularRootElements ? window.getAllAngularRootElements() : [];
 			if (roots.length === 0) {
@@ -119,28 +136,7 @@ func (ah *AngularHelper) waitForZoneStability(ctx context.Context) error {
 			}
 
 			if (!zone) {
-				// Fallback: check window.Zone
-				if (window.Zone && window.Zone.current && window.Zone.current._inner) {
-					const isStable = !window.Zone.current._inner._hasPendingMicrotasks &&
-						!window.Zone.current._inner._hasPendingMacrotasks;
-					if (isStable) {
-						resolve(true);
-					} else {
-						// Poll for stability
-						let attempts = 0;
-						const poll = setInterval(() => {
-							attempts++;
-							const stable = !window.Zone.current._inner._hasPendingMicrotasks &&
-								!window.Zone.current._inner._hasPendingMacrotasks;
-							if (stable || attempts > 100) {
-								clearInterval(poll);
-								resolve(stable);
-							}
-						}, 50);
-					}
-				} else {
-					resolve(true);
-				}
+				pollZone();
 				return;
 			}
 
@@ -151,30 +147,28 @@ func (ah *AngularHelper) waitForZoneStability(ctx context.Context) error {
 			}
 
 			// Wait for stability
-			const sub = zone.onStable.subscribe(() => {
-				sub.unsubscribe();
-				resolve(true);
-			});
-
-			// Timeout fallback
-			setTimeout(() => {
-				sub.unsubscribe();
-				resolve(zone.isStable);
-			}, 5000);
+			try {
+				const sub = zone.onStable.subscribe(() => {
+					sub.unsubscribe();
+					resolve(true);
+				});
+			} catch (e) {
+				pollZone();
+			}
 		})
 	`
 
-	ticker := time.NewTicker(100 * time.Millisecond)
-	defer ticker.Stop()
-
-	// First evaluate the promise
-	_, err := ah.wv.evaluate(ctx, script)
+	result, err := ah.wv.evaluate(ctx, script)
 	if err != nil {
 		// If the script fails, fall back to simple polling
 		return ah.pollForStability(ctx)
 	}
 
-	return nil
+	if stable, ok := result.(bool); ok && stable {
+		return nil
+	}
+
+	return ah.pollForStability(ctx)
 }
 
 // pollForStability polls for Angular stability as a fallback.
@@ -213,7 +207,7 @@ func (ah *AngularHelper) NavigateByRouter(path string) error {
 	ctx, cancel := context.WithTimeout(ah.wv.ctx, ah.timeout)
 	defer cancel()
 
-	script := fmt.Sprintf(`
+	script := core.Sprintf(`
 		(function() {
 			const roots = window.getAllAngularRootElements ? window.getAllAngularRootElements() : [];
 			if (roots.length === 0) {
@@ -238,7 +232,7 @@ func (ah *AngularHelper) NavigateByRouter(path string) error {
 
 	_, err := ah.wv.evaluate(ctx, script)
 	if err != nil {
-		return fmt.Errorf("failed to navigate: %w", err)
+		return coreerr.E("AngularHelper.NavigateByRouter", "failed to navigate", err)
 	}
 
 	// Wait for navigation to complete
@@ -279,13 +273,13 @@ func (ah *AngularHelper) GetRouterState() (*AngularRouterState, error) {
 	}
 
 	if result == nil {
-		return nil, fmt.Errorf("could not get router state")
+		return nil, coreerr.E("AngularHelper.GetRouterState", "could not get router state", nil)
 	}
 
 	// Parse result
 	resultMap, ok := result.(map[string]any)
 	if !ok {
-		return nil, fmt.Errorf("invalid router state format")
+		return nil, coreerr.E("AngularHelper.GetRouterState", "invalid router state format", nil)
 	}
 
 	state := &AngularRouterState{
@@ -330,19 +324,21 @@ func (ah *AngularHelper) GetComponentProperty(selector, propertyName string) (an
 	ctx, cancel := context.WithTimeout(ah.wv.ctx, ah.timeout)
 	defer cancel()
 
-	script := fmt.Sprintf(`
-		(function() {
-			const element = document.querySelector(%q);
-			if (!element) {
-				throw new Error('Element not found: %s');
-			}
-			const component = window.ng.probe(element).componentInstance;
-			if (!component) {
-				throw new Error('No Angular component found on element');
-			}
-			return component[%q];
-		})()
-	`, selector, selector, propertyName)
+	script := core.Sprintf(`
+			(function() {
+				const selector = %s;
+				const propertyName = %s;
+				const element = document.querySelector(selector);
+				if (!element) {
+					throw new Error('Element not found: ' + selector);
+				}
+				const component = window.ng.probe(element).componentInstance;
+				if (!component) {
+					throw new Error('No Angular component found on element');
+				}
+				return component[propertyName];
+			})()
+		`, formatJSValue(selector), formatJSValue(propertyName))
 
 	return ah.wv.evaluate(ctx, script)
 }
@@ -352,27 +348,29 @@ func (ah *AngularHelper) SetComponentProperty(selector, propertyName string, val
 	ctx, cancel := context.WithTimeout(ah.wv.ctx, ah.timeout)
 	defer cancel()
 
-	script := fmt.Sprintf(`
-		(function() {
-			const element = document.querySelector(%q);
-			if (!element) {
-				throw new Error('Element not found: %s');
-			}
-			const component = window.ng.probe(element).componentInstance;
-			if (!component) {
-				throw new Error('No Angular component found on element');
-			}
-			component[%q] = %v;
+	script := core.Sprintf(`
+			(function() {
+				const selector = %s;
+				const propertyName = %s;
+				const element = document.querySelector(selector);
+				if (!element) {
+					throw new Error('Element not found: ' + selector);
+				}
+				const component = window.ng.probe(element).componentInstance;
+				if (!component) {
+					throw new Error('No Angular component found on element');
+				}
+				component[propertyName] = %s;
 
-			// Trigger change detection
-			const injector = window.ng.probe(element).injector;
-			const appRef = injector.get(window.ng.coreTokens.ApplicationRef || 'ApplicationRef');
-			if (appRef) {
+				// Trigger change detection
+				const injector = window.ng.probe(element).injector;
+				const appRef = injector.get(window.ng.coreTokens.ApplicationRef || 'ApplicationRef');
+				if (appRef) {
 				appRef.tick();
-			}
-			return true;
-		})()
-	`, selector, selector, propertyName, formatJSValue(value))
+				}
+				return true;
+			})()
+		`, formatJSValue(selector), formatJSValue(propertyName), formatJSValue(value))
 
 	_, err := ah.wv.evaluate(ctx, script)
 	return err
@@ -383,7 +381,7 @@ func (ah *AngularHelper) CallComponentMethod(selector, methodName string, args .
 	ctx, cancel := context.WithTimeout(ah.wv.ctx, ah.timeout)
 	defer cancel()
 
-	var argsStr strings.Builder
+	argsStr := core.NewBuilder()
 	for i, arg := range args {
 		if i > 0 {
 			argsStr.WriteString(", ")
@@ -391,30 +389,32 @@ func (ah *AngularHelper) CallComponentMethod(selector, methodName string, args .
 		argsStr.WriteString(formatJSValue(arg))
 	}
 
-	script := fmt.Sprintf(`
-		(function() {
-			const element = document.querySelector(%q);
-			if (!element) {
-				throw new Error('Element not found: %s');
-			}
-			const component = window.ng.probe(element).componentInstance;
-			if (!component) {
-				throw new Error('No Angular component found on element');
-			}
-			if (typeof component[%q] !== 'function') {
-				throw new Error('Method not found: %s');
-			}
-			const result = component[%q](%s);
+	script := core.Sprintf(`
+			(function() {
+				const selector = %s;
+				const methodName = %s;
+				const element = document.querySelector(selector);
+				if (!element) {
+					throw new Error('Element not found: ' + selector);
+				}
+				const component = window.ng.probe(element).componentInstance;
+				if (!component) {
+					throw new Error('No Angular component found on element');
+				}
+				if (typeof component[methodName] !== 'function') {
+					throw new Error('Method not found: ' + methodName);
+				}
+				const result = component[methodName](%s);
 
-			// Trigger change detection
-			const injector = window.ng.probe(element).injector;
-			const appRef = injector.get(window.ng.coreTokens.ApplicationRef || 'ApplicationRef');
-			if (appRef) {
+				// Trigger change detection
+				const injector = window.ng.probe(element).injector;
+				const appRef = injector.get(window.ng.coreTokens.ApplicationRef || 'ApplicationRef');
+				if (appRef) {
 				appRef.tick();
-			}
-			return result;
-		})()
-	`, selector, selector, methodName, methodName, methodName, argsStr.String())
+				}
+				return result;
+			})()
+		`, formatJSValue(selector), formatJSValue(methodName), argsStr.String())
 
 	return ah.wv.evaluate(ctx, script)
 }
@@ -452,7 +452,7 @@ func (ah *AngularHelper) GetService(serviceName string) (any, error) {
 	ctx, cancel := context.WithTimeout(ah.wv.ctx, ah.timeout)
 	defer cancel()
 
-	script := fmt.Sprintf(`
+	script := core.Sprintf(`
 		(function() {
 			const roots = window.getAllAngularRootElements ? window.getAllAngularRootElements() : [];
 			for (const root of roots) {
@@ -479,7 +479,7 @@ func (ah *AngularHelper) WaitForComponent(selector string) error {
 	ctx, cancel := context.WithTimeout(ah.wv.ctx, ah.timeout)
 	defer cancel()
 
-	script := fmt.Sprintf(`
+	script := core.Sprintf(`
 		(function() {
 			const element = document.querySelector(%q);
 			if (!element) return false;
@@ -521,17 +521,19 @@ func (ah *AngularHelper) DispatchEvent(selector, eventName string, detail any) e
 		detailStr = formatJSValue(detail)
 	}
 
-	script := fmt.Sprintf(`
-		(function() {
-			const element = document.querySelector(%q);
-			if (!element) {
-				throw new Error('Element not found: %s');
-			}
-			const event = new CustomEvent(%q, { bubbles: true, detail: %s });
-			element.dispatchEvent(event);
-			return true;
-		})()
-	`, selector, selector, eventName, detailStr)
+	script := core.Sprintf(`
+			(function() {
+				const selector = %s;
+				const eventName = %s;
+				const element = document.querySelector(selector);
+				if (!element) {
+					throw new Error('Element not found: ' + selector);
+				}
+				const event = new CustomEvent(eventName, { bubbles: true, detail: %s });
+				element.dispatchEvent(event);
+				return true;
+			})()
+		`, formatJSValue(selector), formatJSValue(eventName), detailStr)
 
 	_, err := ah.wv.evaluate(ctx, script)
 	return err
@@ -542,7 +544,7 @@ func (ah *AngularHelper) GetNgModel(selector string) (any, error) {
 	ctx, cancel := context.WithTimeout(ah.wv.ctx, ah.timeout)
 	defer cancel()
 
-	script := fmt.Sprintf(`
+	script := core.Sprintf(`
 		(function() {
 			const element = document.querySelector(%q);
 			if (!element) return null;
@@ -569,18 +571,19 @@ func (ah *AngularHelper) SetNgModel(selector string, value any) error {
 	ctx, cancel := context.WithTimeout(ah.wv.ctx, ah.timeout)
 	defer cancel()
 
-	script := fmt.Sprintf(`
-		(function() {
-			const element = document.querySelector(%q);
-			if (!element) {
-				throw new Error('Element not found: %s');
-			}
+	script := core.Sprintf(`
+			(function() {
+				const selector = %s;
+				const element = document.querySelector(selector);
+				if (!element) {
+					throw new Error('Element not found: ' + selector);
+				}
 
-			element.value = %v;
-			element.dispatchEvent(new Event('input', { bubbles: true }));
-			element.dispatchEvent(new Event('change', { bubbles: true }));
+				element.value = %s;
+				element.dispatchEvent(new Event('input', { bubbles: true }));
+				element.dispatchEvent(new Event('change', { bubbles: true }));
 
-			// Trigger change detection
+				// Trigger change detection
 			const roots = window.getAllAngularRootElements ? window.getAllAngularRootElements() : [];
 			for (const root of roots) {
 				try {
@@ -593,9 +596,9 @@ func (ah *AngularHelper) SetNgModel(selector string, value any) error {
 				} catch (e) {}
 			}
 
-			return true;
-		})()
-	`, selector, selector, formatJSValue(value))
+				return true;
+			})()
+		`, formatJSValue(selector), formatJSValue(value))
 
 	_, err := ah.wv.evaluate(ctx, script)
 	return err
@@ -611,17 +614,15 @@ func getString(m map[string]any, key string) string {
 }
 
 func formatJSValue(v any) string {
-	switch val := v.(type) {
-	case string:
-		return fmt.Sprintf("%q", val)
-	case bool:
-		if val {
-			return "true"
-		}
-		return "false"
-	case nil:
-		return "null"
-	default:
-		return fmt.Sprintf("%v", val)
+	r := core.JSONMarshal(v)
+	if r.OK {
+		return string(r.Value.([]byte))
 	}
+
+	r = core.JSONMarshal(core.Sprint(v))
+	if r.OK {
+		return string(r.Value.([]byte))
+	}
+
+	return "null"
 }

audit_issue2_test.go

@@ -0,0 +1,673 @@
+// SPDX-License-Identifier: EUPL-1.2
+package webview
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"sync"
+	"testing"
+	"time"
+
+	core "dappco.re/go/core"
+
+	"github.com/gorilla/websocket"
+)
+
+type fakeCDPServer struct {
+	t          *testing.T
+	server     *httptest.Server
+	mu         sync.Mutex
+	nextTarget int
+	targets    map[string]*fakeCDPTarget
+}
+
+type fakeCDPTarget struct {
+	server        *fakeCDPServer
+	id            string
+	onConnect     func(*fakeCDPTarget)
+	onMessage     func(*fakeCDPTarget, cdpMessage)
+	connMu        sync.Mutex
+	conn          *websocket.Conn
+	received      chan cdpMessage
+	connected     chan struct{}
+	closed        chan struct{}
+	connectedOnce sync.Once
+	closedOnce    sync.Once
+}
+
+func newFakeCDPServer(t *testing.T) *fakeCDPServer {
+	t.Helper()
+
+	server := &fakeCDPServer{
+		t:       t,
+		targets: make(map[string]*fakeCDPTarget),
+	}
+	server.server = httptest.NewServer(http.HandlerFunc(server.handle))
+	server.addTarget("target-1")
+	t.Cleanup(server.Close)
+
+	return server
+}
+
+func (s *fakeCDPServer) Close() {
+	s.server.Close()
+}
+
+func (s *fakeCDPServer) DebugURL() string {
+	return s.server.URL
+}
+
+func (s *fakeCDPServer) addTarget(id string) *fakeCDPTarget {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	target := &fakeCDPTarget{
+		server:    s,
+		id:        id,
+		received:  make(chan cdpMessage, 16),
+		connected: make(chan struct{}),
+		closed:    make(chan struct{}),
+	}
+	s.targets[id] = target
+	return target
+}
+
+func (s *fakeCDPServer) newTarget() *fakeCDPTarget {
+	s.mu.Lock()
+	s.nextTarget++
+	id := core.Sprintf("target-%d", s.nextTarget+1)
+	s.mu.Unlock()
+
+	return s.addTarget(id)
+}
+
+func (s *fakeCDPServer) primaryTarget() *fakeCDPTarget {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.targets["target-1"]
+}
+
+func (s *fakeCDPServer) handle(w http.ResponseWriter, r *http.Request) {
+	switch {
+	case r.URL.Path == "/json":
+		s.handleListTargets(w)
+	case r.URL.Path == "/json/new":
+		s.handleNewTarget(w)
+	case r.URL.Path == "/json/version":
+		s.writeJSON(w, map[string]string{
+			"Browser": "Chrome/123.0",
+		})
+	case core.HasPrefix(r.URL.Path, "/devtools/page/"):
+		s.handleWebSocket(w, r, core.TrimPrefix(r.URL.Path, "/devtools/page/"))
+	default:
+		http.NotFound(w, r)
+	}
+}
+
+func (s *fakeCDPServer) handleListTargets(w http.ResponseWriter) {
+	s.mu.Lock()
+	targets := make([]TargetInfo, 0, len(s.targets))
+	for id := range s.targets {
+		targets = append(targets, TargetInfo{
+			ID:                   id,
+			Type:                 "page",
+			Title:                id,
+			URL:                  "about:blank",
+			WebSocketDebuggerURL: s.webSocketURL(id),
+		})
+	}
+	s.mu.Unlock()
+
+	s.writeJSON(w, targets)
+}
+
+func (s *fakeCDPServer) handleNewTarget(w http.ResponseWriter) {
+	target := s.newTarget()
+	s.writeJSON(w, TargetInfo{
+		ID:                   target.id,
+		Type:                 "page",
+		Title:                target.id,
+		URL:                  "about:blank",
+		WebSocketDebuggerURL: s.webSocketURL(target.id),
+	})
+}
+
+func (s *fakeCDPServer) handleWebSocket(w http.ResponseWriter, r *http.Request, id string) {
+	s.mu.Lock()
+	target := s.targets[id]
+	s.mu.Unlock()
+	if target == nil {
+		http.NotFound(w, r)
+		return
+	}
+
+	upgrader := websocket.Upgrader{
+		CheckOrigin: func(*http.Request) bool { return true },
+	}
+	conn, err := upgrader.Upgrade(w, r, nil)
+	if err != nil {
+		s.t.Fatalf("failed to upgrade test WebSocket: %v", err)
+	}
+
+	target.attach(conn)
+}
+
+func (s *fakeCDPServer) writeJSON(w http.ResponseWriter, value any) {
+	s.t.Helper()
+
+	w.Header().Set("Content-Type", "application/json")
+	if err := json.NewEncoder(w).Encode(value); err != nil {
+		s.t.Fatalf("failed to encode JSON: %v", err)
+	}
+}
+
+func (s *fakeCDPServer) webSocketURL(id string) string {
+	wsURL, err := url.Parse(s.server.URL)
+	if err != nil {
+		s.t.Fatalf("failed to parse test server URL: %v", err)
+	}
+	if wsURL.Scheme == "http" {
+		wsURL.Scheme = "ws"
+	} else {
+		wsURL.Scheme = "wss"
+	}
+	wsURL.Path = "/devtools/page/" + id
+	wsURL.RawQuery = ""
+	wsURL.Fragment = ""
+
+	return wsURL.String()
+}
+
+func (tgt *fakeCDPTarget) attach(conn *websocket.Conn) {
+	tgt.connMu.Lock()
+	tgt.conn = conn
+	tgt.connMu.Unlock()
+
+	tgt.connectedOnce.Do(func() {
+		close(tgt.connected)
+	})
+
+	go tgt.readLoop()
+
+	if tgt.onConnect != nil {
+		go tgt.onConnect(tgt)
+	}
+}
+
+func (tgt *fakeCDPTarget) readLoop() {
+	defer tgt.closedOnce.Do(func() {
+		close(tgt.closed)
+	})
+
+	for {
+		_, data, err := tgt.conn.ReadMessage()
+		if err != nil {
+			return
+		}
+
+		var msg cdpMessage
+		if r := core.JSONUnmarshal(data, &msg); !r.OK {
+			continue
+		}
+
+		select {
+		case tgt.received <- msg:
+		default:
+		}
+
+		if tgt.onMessage != nil {
+			tgt.onMessage(tgt, msg)
+		}
+	}
+}
+
+func (tgt *fakeCDPTarget) reply(id int64, result map[string]any) {
+	tgt.writeJSON(cdpResponse{
+		ID:     id,
+		Result: result,
+	})
+}
+
+func (tgt *fakeCDPTarget) replyError(id int64, message string) {
+	tgt.writeJSON(cdpResponse{
+		ID: id,
+		Error: &cdpError{
+			Message: message,
+		},
+	})
+}
+
+func (tgt *fakeCDPTarget) replyValue(id int64, value any) {
+	tgt.reply(id, map[string]any{
+		"result": map[string]any{
+			"value": value,
+		},
+	})
+}
+
+func (tgt *fakeCDPTarget) writeJSON(value any) {
+	tgt.server.t.Helper()
+
+	tgt.connMu.Lock()
+	defer tgt.connMu.Unlock()
+	if tgt.conn == nil {
+		tgt.server.t.Fatal("test WebSocket connection was not established")
+	}
+	if err := tgt.conn.WriteJSON(value); err != nil {
+		tgt.server.t.Fatalf("failed to write test WebSocket message: %v", err)
+	}
+}
+
+func (tgt *fakeCDPTarget) closeWebSocket() {
+	tgt.connMu.Lock()
+	defer tgt.connMu.Unlock()
+	if tgt.conn != nil {
+		_ = tgt.conn.Close()
+	}
+}
+
+func (tgt *fakeCDPTarget) waitForMessage(tb testing.TB) cdpMessage {
+	tb.Helper()
+
+	select {
+	case msg := <-tgt.received:
+		return msg
+	case <-time.After(time.Second):
+		tb.Fatal("timed out waiting for CDP message")
+		return cdpMessage{}
+	}
+}
+
+func (tgt *fakeCDPTarget) waitConnected(tb testing.TB) {
+	tb.Helper()
+
+	select {
+	case <-tgt.connected:
+	case <-time.After(time.Second):
+		tb.Fatal("timed out waiting for WebSocket connection")
+	}
+}
+
+func (tgt *fakeCDPTarget) waitClosed(tb testing.TB) {
+	tb.Helper()
+
+	select {
+	case <-tgt.closed:
+	case <-time.After(time.Second):
+		tb.Fatal("timed out waiting for WebSocket closure")
+	}
+}
+
+func TestCDPClientClose_Good_UnblocksReadLoop(t *testing.T) {
+	server := newFakeCDPServer(t)
+	target := server.primaryTarget()
+
+	client, err := NewCDPClient(server.DebugURL())
+	if err != nil {
+		t.Fatalf("NewCDPClient returned error: %v", err)
+	}
+
+	target.waitConnected(t)
+
+	done := make(chan error, 1)
+	go func() {
+		done <- client.Close()
+	}()
+
+	select {
+	case err := <-done:
+		if err != nil {
+			t.Fatalf("Close returned error: %v", err)
+		}
+	case <-time.After(time.Second):
+		t.Fatal("Close blocked waiting for readLoop")
+	}
+}
+
+func TestCDPClientReadLoop_Ugly_StopsOnTerminalReadError(t *testing.T) {
+	server := newFakeCDPServer(t)
+	target := server.primaryTarget()
+	target.onConnect = func(target *fakeCDPTarget) {
+		target.closeWebSocket()
+	}
+
+	client, err := NewCDPClient(server.DebugURL())
+	if err != nil {
+		t.Fatalf("NewCDPClient returned error: %v", err)
+	}
+
+	select {
+	case <-client.done:
+	case <-time.After(time.Second):
+		t.Fatal("readLoop did not stop after terminal read error")
+	}
+}
+
+func TestCDPClientCloseTab_Good_ClosesTargetOnly(t *testing.T) {
+	server := newFakeCDPServer(t)
+	target := server.primaryTarget()
+	target.onMessage = func(target *fakeCDPTarget, msg cdpMessage) {
+		if msg.Method != "Target.closeTarget" {
+			t.Fatalf("CloseTab sent %q, want Target.closeTarget", msg.Method)
+		}
+		if got := msg.Params["targetId"]; got != target.id {
+			t.Fatalf("Target.closeTarget targetId = %v, want %q", got, target.id)
+		}
+		target.reply(msg.ID, map[string]any{"success": true})
+		go func() {
+			time.Sleep(10 * time.Millisecond)
+			target.closeWebSocket()
+		}()
+	}
+
+	client, err := NewCDPClient(server.DebugURL())
+	if err != nil {
+		t.Fatalf("NewCDPClient returned error: %v", err)
+	}
+
+	if err := client.CloseTab(); err != nil {
+		t.Fatalf("CloseTab returned error: %v", err)
+	}
+
+	msg := target.waitForMessage(t)
+	if msg.Method == "Browser.close" {
+		t.Fatal("CloseTab closed the whole browser")
+	}
+}
+
+func TestCDPClientDispatchEvent_Good_HandlerParamsAreIsolated(t *testing.T) {
+	client := &CDPClient{
+		handlers: make(map[string][]func(map[string]any)),
+	}
+
+	firstDone := make(chan map[string]any, 1)
+	secondDone := make(chan map[string]any, 1)
+
+	client.OnEvent("Runtime.testEvent", func(params map[string]any) {
+		params["value"] = "mutated"
+		params["nested"].(map[string]any)["count"] = 1
+		params["items"].([]any)[0].(map[string]any)["id"] = "changed"
+		firstDone <- params
+	})
+	client.OnEvent("Runtime.testEvent", func(params map[string]any) {
+		secondDone <- params
+	})
+
+	original := map[string]any{
+		"nested": map[string]any{"count": 0},
+		"items":  []any{map[string]any{"id": "original"}},
+	}
+
+	client.dispatchEvent("Runtime.testEvent", original)
+
+	select {
+	case <-firstDone:
+	case <-time.After(time.Second):
+		t.Fatal("first handler did not run")
+	}
+
+	var secondParams map[string]any
+	select {
+	case secondParams = <-secondDone:
+	case <-time.After(time.Second):
+		t.Fatal("second handler did not run")
+	}
+
+	if _, ok := secondParams["value"]; ok {
+		t.Fatal("second handler observed first handler mutation")
+	}
+	if got := secondParams["nested"].(map[string]any)["count"]; got != 0 {
+		t.Fatalf("second handler nested count = %v, want 0", got)
+	}
+	if got := secondParams["items"].([]any)[0].(map[string]any)["id"]; got != "original" {
+		t.Fatalf("second handler slice payload = %v, want %q", got, "original")
+	}
+	if got := original["nested"].(map[string]any)["count"]; got != 0 {
+		t.Fatalf("original params were mutated: nested count = %v", got)
+	}
+}
+
+func TestNewCDPClient_Bad_RejectsCrossHostWebSocket(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/json" {
+			http.NotFound(w, r)
+			return
+		}
+		w.Header().Set("Content-Type", "application/json")
+		if err := json.NewEncoder(w).Encode([]TargetInfo{{
+			ID:                   "target-1",
+			Type:                 "page",
+			WebSocketDebuggerURL: "ws://example.com/devtools/page/target-1",
+		}}); err != nil {
+			t.Fatalf("failed to encode targets: %v", err)
+		}
+	}))
+	defer server.Close()
+
+	_, err := NewCDPClient(server.URL)
+	if err == nil {
+		t.Fatal("NewCDPClient succeeded with a cross-host WebSocket URL")
+	}
+	if !core.Contains(err.Error(), "invalid target WebSocket URL") {
+		t.Fatalf("NewCDPClient error = %v, want cross-host WebSocket validation failure", err)
+	}
+}
+
+func TestWebviewNew_Bad_ClosesClientWhenEnableConsoleFails(t *testing.T) {
+	server := newFakeCDPServer(t)
+	target := server.primaryTarget()
+	target.onMessage = func(target *fakeCDPTarget, msg cdpMessage) {
+		if msg.Method != "Runtime.enable" {
+			t.Fatalf("enableConsole sent %q before Runtime.enable failed", msg.Method)
+		}
+		target.replyError(msg.ID, "runtime disabled")
+	}
+
+	_, err := New(
+		WithTimeout(250*time.Millisecond),
+		WithDebugURL(server.DebugURL()),
+	)
+	if err == nil {
+		t.Fatal("New succeeded when Runtime.enable failed")
+	}
+
+	target.waitClosed(t)
+}
+
+func TestAngularHelperWaitForZoneStability_Good_AwaitsPromise(t *testing.T) {
+	server := newFakeCDPServer(t)
+	target := server.primaryTarget()
+	target.onMessage = func(target *fakeCDPTarget, msg cdpMessage) {
+		if msg.Method != "Runtime.evaluate" {
+			t.Fatalf("unexpected method %q", msg.Method)
+		}
+		target.replyValue(msg.ID, true)
+	}
+
+	client, err := NewCDPClient(server.DebugURL())
+	if err != nil {
+		t.Fatalf("NewCDPClient returned error: %v", err)
+	}
+	defer func() { _ = client.Close() }()
+
+	wv := &Webview{
+		client:  client,
+		ctx:     context.Background(),
+		timeout: time.Second,
+	}
+	ah := NewAngularHelper(wv)
+
+	if err := ah.waitForZoneStability(context.Background()); err != nil {
+		t.Fatalf("waitForZoneStability returned error: %v", err)
+	}
+
+	msg := target.waitForMessage(t)
+	if got := msg.Params["awaitPromise"]; got != true {
+		t.Fatalf("Runtime.evaluate awaitPromise = %v, want true", got)
+	}
+	if got := msg.Params["returnByValue"]; got != true {
+		t.Fatalf("Runtime.evaluate returnByValue = %v, want true", got)
+	}
+}
+
+func TestAngularHelperSetNgModel_Good_EscapesSelectorAndValue(t *testing.T) {
+	server := newFakeCDPServer(t)
+	target := server.primaryTarget()
+	target.onMessage = func(target *fakeCDPTarget, msg cdpMessage) {
+		if msg.Method != "Runtime.evaluate" {
+			t.Fatalf("unexpected method %q", msg.Method)
+		}
+		target.replyValue(msg.ID, true)
+	}
+
+	client, err := NewCDPClient(server.DebugURL())
+	if err != nil {
+		t.Fatalf("NewCDPClient returned error: %v", err)
+	}
+	defer func() { _ = client.Close() }()
+
+	wv := &Webview{
+		client:  client,
+		ctx:     context.Background(),
+		timeout: time.Second,
+	}
+	ah := NewAngularHelper(wv)
+
+	selector := `input[name="x'];window.hacked=true;//"]`
+	value := `";window.hacked=true;//`
+	if err := ah.SetNgModel(selector, value); err != nil {
+		t.Fatalf("SetNgModel returned error: %v", err)
+	}
+
+	expression, _ := target.waitForMessage(t).Params["expression"].(string)
+	if !core.Contains(expression, "const selector = "+formatJSValue(selector)+";") {
+		t.Fatalf("expression did not contain safely quoted selector: %s", expression)
+	}
+	if !core.Contains(expression, "element.value = "+formatJSValue(value)+";") {
+		t.Fatalf("expression did not contain safely quoted value: %s", expression)
+	}
+	if core.Contains(expression, "throw new Error('Element not found: "+selector+"')") {
+		t.Fatalf("expression still embedded selector directly in error text: %s", expression)
+	}
+}
+
+func TestConsoleWatcherWaitForMessage_Good_IsolatesTemporaryHandlers(t *testing.T) {
+	cw := &ConsoleWatcher{
+		messages: make([]ConsoleMessage, 0),
+		filters:  make([]ConsoleFilter, 0),
+		limit:    1000,
+		handlers: make([]consoleHandlerRegistration, 0),
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+
+	results := make(chan string, 2)
+	errorsCh := make(chan error, 2)
+
+	go func() {
+		msg, err := cw.WaitForMessage(ctx, ConsoleFilter{Type: "error"})
+		if err != nil {
+			errorsCh <- err
+			return
+		}
+		results <- "error:" + msg.Text
+	}()
+	go func() {
+		msg, err := cw.WaitForMessage(ctx, ConsoleFilter{Type: "log"})
+		if err != nil {
+			errorsCh <- err
+			return
+		}
+		results <- "log:" + msg.Text
+	}()
+
+	time.Sleep(20 * time.Millisecond)
+	cw.addMessage(ConsoleMessage{Type: "error", Text: "first"})
+	time.Sleep(20 * time.Millisecond)
+	cw.addMessage(ConsoleMessage{Type: "log", Text: "second"})
+
+	got := make(map[string]bool, 2)
+	for range 2 {
+		select {
+		case err := <-errorsCh:
+			t.Fatalf("WaitForMessage returned error: %v", err)
+		case result := <-results:
+			got[result] = true
+		case <-time.After(time.Second):
+			t.Fatal("timed out waiting for console waiter results")
+		}
+	}
+
+	if !got["error:first"] || !got["log:second"] {
+		t.Fatalf("unexpected console waiter results: %#v", got)
+	}
+	if len(cw.handlers) != 0 {
+		t.Fatalf("temporary handlers leaked: %d", len(cw.handlers))
+	}
+}
+
+func TestExceptionWatcherWaitForException_Good_PreservesExistingHandlers(t *testing.T) {
+	ew := &ExceptionWatcher{
+		exceptions: make([]ExceptionInfo, 0),
+		handlers:   make([]exceptionHandlerRegistration, 0),
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+
+	waitDone := make(chan error, 1)
+	go func() {
+		_, err := ew.WaitForException(ctx)
+		waitDone <- err
+	}()
+
+	time.Sleep(20 * time.Millisecond)
+
+	var mu sync.Mutex
+	count := 0
+	ew.AddHandler(func(ExceptionInfo) {
+		mu.Lock()
+		defer mu.Unlock()
+		count++
+	})
+
+	ew.handleException(map[string]any{
+		"exceptionDetails": map[string]any{
+			"text":         "first",
+			"lineNumber":   float64(1),
+			"columnNumber": float64(1),
+			"url":          "https://example.com/app.js",
+		},
+	})
+
+	select {
+	case err := <-waitDone:
+		if err != nil {
+			t.Fatalf("WaitForException returned error: %v", err)
+		}
+	case <-time.After(time.Second):
+		t.Fatal("timed out waiting for exception waiter")
+	}
+
+	ew.handleException(map[string]any{
+		"exceptionDetails": map[string]any{
+			"text":         "second",
+			"lineNumber":   float64(2),
+			"columnNumber": float64(1),
+			"url":          "https://example.com/app.js",
+		},
+	})
+
+	mu.Lock()
+	defer mu.Unlock()
+	if count != 2 {
+		t.Fatalf("persistent handler count = %d, want 2", count)
+	}
+	if len(ew.handlers) != 1 {
+		t.Fatalf("unexpected handler count after waiter removal: %d", len(ew.handlers))
+	}
+}

cdp.go

@@ -1,25 +1,45 @@
+// SPDX-License-Identifier: EUPL-1.2
 package webview
 
 import (
 	"context"
-	"encoding/json"
-	"fmt"
 	"io"
 	"iter"
+	"net"
 	"net/http"
+	"net/url"
+	"path"
 	"slices"
+	"strings"
 	"sync"
 	"sync/atomic"
+	"time"
+
+	core "dappco.re/go/core"
+	coreerr "dappco.re/go/core/log"
 
 	"github.com/gorilla/websocket"
 )
 
+const debugEndpointTimeout = 10 * time.Second
+
+var (
+	defaultDebugHTTPClient = &http.Client{
+		Timeout: debugEndpointTimeout,
+		CheckRedirect: func(*http.Request, []*http.Request) error {
+			return http.ErrUseLastResponse
+		},
+	}
+	errCDPClientClosed = core.NewError("cdp client closed")
+)
+
 // CDPClient handles communication with Chrome DevTools Protocol via WebSocket.
 type CDPClient struct {
-	mu       sync.RWMutex
-	conn     *websocket.Conn
-	debugURL string
-	wsURL    string
+	mu        sync.RWMutex
+	conn      *websocket.Conn
+	debugURL  string
+	debugBase *url.URL
+	wsURL     string
 
 	// Message tracking
 	msgID   atomic.Int64
@@ -31,9 +51,11 @@ type CDPClient struct {
 	handMu   sync.RWMutex
 
 	// Lifecycle
-	ctx    context.Context
-	cancel context.CancelFunc
-	done   chan struct{}
+	ctx       context.Context
+	cancel    context.CancelFunc
+	done      chan struct{}
+	closeOnce sync.Once
+	closeErr  error
 }
 
 // cdpMessage represents a CDP protocol message.
@@ -63,8 +85,8 @@ type cdpError struct {
 	Data    string `json:"data,omitempty"`
 }
 
-// targetInfo represents Chrome DevTools target information.
-type targetInfo struct {
+// TargetInfo represents Chrome DevTools target information.
+type TargetInfo struct {
 	ID                   string `json:"id"`
 	Type                 string `json:"type"`
 	Title                string `json:"title"`
@@ -75,87 +97,64 @@ type targetInfo struct {
 // NewCDPClient creates a new CDP client connected to the given debug URL.
 // The debug URL should be the Chrome DevTools HTTP endpoint (e.g., http://localhost:9222).
 func NewCDPClient(debugURL string) (*CDPClient, error) {
-	// Get available targets
-	resp, err := http.Get(debugURL + "/json")
+	debugBase, err := parseDebugURL(debugURL)
 	if err != nil {
-		return nil, fmt.Errorf("failed to get targets: %w", err)
-	}
-	defer func() { _ = resp.Body.Close() }()
-
-	body, err := io.ReadAll(resp.Body)
-	if err != nil {
-		return nil, fmt.Errorf("failed to read targets: %w", err)
+		return nil, coreerr.E("CDPClient.New", "invalid debug URL", err)
 	}
 
-	var targets []targetInfo
-	if err := json.Unmarshal(body, &targets); err != nil {
-		return nil, fmt.Errorf("failed to parse targets: %w", err)
+	ctx, cancel := context.WithTimeout(context.Background(), debugEndpointTimeout)
+	defer cancel()
+
+	targets, err := listTargetsAt(ctx, debugBase)
+	if err != nil {
+		return nil, coreerr.E("CDPClient.New", "failed to get targets", err)
 	}
 
 	// Find a page target
 	var wsURL string
 	for _, t := range targets {
 		if t.Type == "page" && t.WebSocketDebuggerURL != "" {
-			wsURL = t.WebSocketDebuggerURL
+			wsURL, err = validateTargetWebSocketURL(debugBase, t.WebSocketDebuggerURL)
+			if err != nil {
+				return nil, coreerr.E("CDPClient.New", "invalid target WebSocket URL", err)
+			}
 			break
 		}
 	}
 
 	if wsURL == "" {
-		// Try to create a new target
-		resp, err := http.Get(debugURL + "/json/new")
+		newTarget, err := createTargetAt(ctx, debugBase, "")
 		if err != nil {
-			return nil, fmt.Errorf("no page targets found and failed to create new: %w", err)
+			return nil, coreerr.E("CDPClient.New", "no page targets found and failed to create new", err)
 		}
-		defer func() { _ = resp.Body.Close() }()
 
-		body, err := io.ReadAll(resp.Body)
+		wsURL, err = validateTargetWebSocketURL(debugBase, newTarget.WebSocketDebuggerURL)
 		if err != nil {
-			return nil, fmt.Errorf("failed to read new target: %w", err)
+			return nil, coreerr.E("CDPClient.New", "invalid new target WebSocket URL", err)
 		}
-
-		var newTarget targetInfo
-		if err := json.Unmarshal(body, &newTarget); err != nil {
-			return nil, fmt.Errorf("failed to parse new target: %w", err)
-		}
-
-		wsURL = newTarget.WebSocketDebuggerURL
 	}
 
 	if wsURL == "" {
-		return nil, fmt.Errorf("no WebSocket URL available")
+		return nil, coreerr.E("CDPClient.New", "no WebSocket URL available", nil)
 	}
 
 	// Connect to WebSocket
 	conn, _, err := websocket.DefaultDialer.Dial(wsURL, nil)
 	if err != nil {
-		return nil, fmt.Errorf("failed to connect to WebSocket: %w", err)
+		return nil, coreerr.E("CDPClient.New", "failed to connect to WebSocket", err)
 	}
 
-	ctx, cancel := context.WithCancel(context.Background())
-
-	client := &CDPClient{
-		conn:     conn,
-		debugURL: debugURL,
-		wsURL:    wsURL,
-		pending:  make(map[int64]chan *cdpResponse),
-		handlers: make(map[string][]func(map[string]any)),
-		ctx:      ctx,
-		cancel:   cancel,
-		done:     make(chan struct{}),
-	}
-
-	// Start message reader
-	go client.readLoop()
-
-	return client, nil
+	return newCDPClient(debugBase, wsURL, conn), nil
 }
 
 // Close closes the CDP connection.
 func (c *CDPClient) Close() error {
-	c.cancel()
-	<-c.done // Wait for read loop to finish
-	return c.conn.Close()
+	c.close(errCDPClientClosed)
+	<-c.done
+	if c.closeErr != nil {
+		return coreerr.E("CDPClient.Close", "failed to close WebSocket", c.closeErr)
+	}
+	return nil
 }
 
 // Call sends a CDP method call and waits for the response.
@@ -165,7 +164,7 @@ func (c *CDPClient) Call(ctx context.Context, method string, params map[string]a
 	msg := cdpMessage{
 		ID:     id,
 		Method: method,
-		Params: params,
+		Params: cloneMapAny(params),
 	}
 
 	// Register response channel
@@ -185,16 +184,18 @@ func (c *CDPClient) Call(ctx context.Context, method string, params map[string]a
 	err := c.conn.WriteJSON(msg)
 	c.mu.Unlock()
 	if err != nil {
-		return nil, fmt.Errorf("failed to send message: %w", err)
+		return nil, coreerr.E("CDPClient.Call", "failed to send message", err)
 	}
 
 	// Wait for response
 	select {
 	case <-ctx.Done():
 		return nil, ctx.Err()
+	case <-c.ctx.Done():
+		return nil, coreerr.E("CDPClient.Call", "client closed", errCDPClientClosed)
 	case resp := <-respCh:
 		if resp.Error != nil {
-			return nil, fmt.Errorf("CDP error %d: %s", resp.Error.Code, resp.Error.Message)
+			return nil, coreerr.E("CDPClient.Call", resp.Error.Message, nil)
 		}
 		return resp.Result, nil
 	}
@@ -212,31 +213,35 @@ func (c *CDPClient) readLoop() {
 	defer close(c.done)
 
 	for {
-		select {
-		case <-c.ctx.Done():
-			return
-		default:
-		}
-
 		_, data, err := c.conn.ReadMessage()
 		if err != nil {
-			// Check if context was cancelled
-			select {
-			case <-c.ctx.Done():
+			if c.ctx.Err() != nil {
 				return
-			default:
-				// Log error but continue (could be temporary)
+			}
+			if isTerminalReadError(err) {
+				c.close(err)
+				return
+			}
+
+			var netErr net.Error
+			if core.As(err, &netErr) && netErr.Timeout() {
 				continue
 			}
+
+			c.close(err)
+			return
 		}
 
 		// Try to parse as response
 		var resp cdpResponse
-		if err := json.Unmarshal(data, &resp); err == nil && resp.ID > 0 {
+		if r := core.JSONUnmarshal(data, &resp); r.OK && resp.ID > 0 {
 			c.pendMu.Lock()
 			if ch, ok := c.pending[resp.ID]; ok {
 				respCopy := resp
-				ch <- &respCopy
+				select {
+				case ch <- &respCopy:
+				default:
+				}
 			}
 			c.pendMu.Unlock()
 			continue
@@ -244,7 +249,7 @@ func (c *CDPClient) readLoop() {
 
 		// Try to parse as event
 		var event cdpEvent
-		if err := json.Unmarshal(data, &event); err == nil && event.Method != "" {
+		if r := core.JSONUnmarshal(data, &event); r.OK && event.Method != "" {
 			c.dispatchEvent(event.Method, event.Params)
 		}
 	}
@@ -258,7 +263,8 @@ func (c *CDPClient) dispatchEvent(method string, params map[string]any) {
 
 	for _, handler := range handlers {
 		// Call handler in goroutine to avoid blocking
-		go handler(params)
+		handlerParams := cloneMapAny(params)
+		go handler(handlerParams)
 	}
 }
 
@@ -266,7 +272,7 @@ func (c *CDPClient) dispatchEvent(method string, params map[string]any) {
 func (c *CDPClient) Send(method string, params map[string]any) error {
 	msg := cdpMessage{
 		Method: method,
-		Params: params,
+		Params: cloneMapAny(params),
 	}
 
 	c.mu.Lock()
@@ -286,90 +292,77 @@ func (c *CDPClient) WebSocketURL() string {
 
 // NewTab creates a new browser tab and returns a new CDPClient connected to it.
 func (c *CDPClient) NewTab(url string) (*CDPClient, error) {
-	endpoint := c.debugURL + "/json/new"
-	if url != "" {
-		endpoint += "?" + url
-	}
+	ctx, cancel := context.WithTimeout(c.ctx, debugEndpointTimeout)
+	defer cancel()
 
-	resp, err := http.Get(endpoint)
+	target, err := createTargetAt(ctx, c.debugBase, url)
 	if err != nil {
-		return nil, fmt.Errorf("failed to create new tab: %w", err)
-	}
-	defer func() { _ = resp.Body.Close() }()
-
-	body, err := io.ReadAll(resp.Body)
-	if err != nil {
-		return nil, fmt.Errorf("failed to read response: %w", err)
-	}
-
-	var target targetInfo
-	if err := json.Unmarshal(body, &target); err != nil {
-		return nil, fmt.Errorf("failed to parse target: %w", err)
+		return nil, coreerr.E("CDPClient.NewTab", "failed to create new tab", err)
 	}
 
 	if target.WebSocketDebuggerURL == "" {
-		return nil, fmt.Errorf("no WebSocket URL for new tab")
+		return nil, coreerr.E("CDPClient.NewTab", "no WebSocket URL for new tab", nil)
+	}
+
+	wsURL, err := validateTargetWebSocketURL(c.debugBase, target.WebSocketDebuggerURL)
+	if err != nil {
+		return nil, coreerr.E("CDPClient.NewTab", "invalid WebSocket URL for new tab", err)
 	}
 
 	// Connect to new tab
-	conn, _, err := websocket.DefaultDialer.Dial(target.WebSocketDebuggerURL, nil)
+	conn, _, err := websocket.DefaultDialer.Dial(wsURL, nil)
 	if err != nil {
-		return nil, fmt.Errorf("failed to connect to new tab: %w", err)
+		return nil, coreerr.E("CDPClient.NewTab", "failed to connect to new tab", err)
 	}
 
-	ctx, cancel := context.WithCancel(context.Background())
-
-	client := &CDPClient{
-		conn:     conn,
-		debugURL: c.debugURL,
-		wsURL:    target.WebSocketDebuggerURL,
-		pending:  make(map[int64]chan *cdpResponse),
-		handlers: make(map[string][]func(map[string]any)),
-		ctx:      ctx,
-		cancel:   cancel,
-		done:     make(chan struct{}),
-	}
-
-	go client.readLoop()
-
-	return client, nil
+	return newCDPClient(c.debugBase, wsURL, conn), nil
 }
 
 // CloseTab closes the current tab (target).
 func (c *CDPClient) CloseTab() error {
-	// Extract target ID from WebSocket URL
-	// Format: ws://host:port/devtools/page/TARGET_ID
-	// We'll use the Browser.close target API
+	targetID, err := targetIDFromWebSocketURL(c.wsURL)
+	if err != nil {
+		return coreerr.E("CDPClient.CloseTab", "failed to determine target ID", err)
+	}
 
-	ctx := context.Background()
-	_, err := c.Call(ctx, "Browser.close", nil)
-	return err
+	ctx, cancel := context.WithTimeout(c.ctx, debugEndpointTimeout)
+	defer cancel()
+
+	result, err := c.Call(ctx, "Target.closeTarget", map[string]any{
+		"targetId": targetID,
+	})
+	if err != nil {
+		return coreerr.E("CDPClient.CloseTab", "failed to close target", err)
+	}
+
+	if success, ok := result["success"].(bool); ok && !success {
+		return coreerr.E("CDPClient.CloseTab", "target close was not acknowledged", nil)
+	}
+
+	return c.Close()
 }
 
 // ListTargets returns all available targets.
-func ListTargets(debugURL string) ([]targetInfo, error) {
-	resp, err := http.Get(debugURL + "/json")
+func ListTargets(debugURL string) ([]TargetInfo, error) {
+	debugBase, err := parseDebugURL(debugURL)
 	if err != nil {
-		return nil, fmt.Errorf("failed to get targets: %w", err)
-	}
-	defer func() { _ = resp.Body.Close() }()
-
-	body, err := io.ReadAll(resp.Body)
-	if err != nil {
-		return nil, fmt.Errorf("failed to read targets: %w", err)
+		return nil, coreerr.E("ListTargets", "invalid debug URL", err)
 	}
 
-	var targets []targetInfo
-	if err := json.Unmarshal(body, &targets); err != nil {
-		return nil, fmt.Errorf("failed to parse targets: %w", err)
+	ctx, cancel := context.WithTimeout(context.Background(), debugEndpointTimeout)
+	defer cancel()
+
+	targets, err := listTargetsAt(ctx, debugBase)
+	if err != nil {
+		return nil, coreerr.E("ListTargets", "failed to get targets", err)
 	}
 
 	return targets, nil
 }
 
 // ListTargetsAll returns an iterator over all available targets.
-func ListTargetsAll(debugURL string) iter.Seq[targetInfo] {
-	return func(yield func(targetInfo) bool) {
+func ListTargetsAll(debugURL string) iter.Seq[TargetInfo] {
+	return func(yield func(TargetInfo) bool) {
 		targets, err := ListTargets(debugURL)
 		if err != nil {
 			return
@@ -384,21 +377,261 @@ func ListTargetsAll(debugURL string) iter.Seq[targetInfo] {
 
 // GetVersion returns Chrome version information.
 func GetVersion(debugURL string) (map[string]string, error) {
-	resp, err := http.Get(debugURL + "/json/version")
+	debugBase, err := parseDebugURL(debugURL)
 	if err != nil {
-		return nil, fmt.Errorf("failed to get version: %w", err)
+		return nil, coreerr.E("GetVersion", "invalid debug URL", err)
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), debugEndpointTimeout)
+	defer cancel()
+
+	body, err := doDebugRequest(ctx, debugBase, "/json/version", "")
+	if err != nil {
+		return nil, coreerr.E("GetVersion", "failed to get version", err)
+	}
+
+	var version map[string]string
+	if r := core.JSONUnmarshal(body, &version); !r.OK {
+		return nil, coreerr.E("GetVersion", "failed to parse version", nil)
+	}
+
+	return version, nil
+}
+
+func newCDPClient(debugBase *url.URL, wsURL string, conn *websocket.Conn) *CDPClient {
+	ctx, cancel := context.WithCancel(context.Background())
+	baseCopy := *debugBase
+
+	client := &CDPClient{
+		conn:      conn,
+		debugURL:  canonicalDebugURL(&baseCopy),
+		debugBase: &baseCopy,
+		wsURL:     wsURL,
+		pending:   make(map[int64]chan *cdpResponse),
+		handlers:  make(map[string][]func(map[string]any)),
+		ctx:       ctx,
+		cancel:    cancel,
+		done:      make(chan struct{}),
+	}
+
+	go client.readLoop()
+
+	return client
+}
+
+func parseDebugURL(raw string) (*url.URL, error) {
+	debugURL, err := url.Parse(raw)
+	if err != nil {
+		return nil, err
+	}
+	if debugURL.Scheme != "http" && debugURL.Scheme != "https" {
+		return nil, coreerr.E("CDPClient.parseDebugURL", "debug URL must use http or https", nil)
+	}
+	if debugURL.Host == "" {
+		return nil, coreerr.E("CDPClient.parseDebugURL", "debug URL host is required", nil)
+	}
+	if debugURL.User != nil {
+		return nil, coreerr.E("CDPClient.parseDebugURL", "debug URL must not include credentials", nil)
+	}
+	if debugURL.RawQuery != "" || debugURL.Fragment != "" {
+		return nil, coreerr.E("CDPClient.parseDebugURL", "debug URL must not include query or fragment", nil)
+	}
+	if debugURL.Path == "" {
+		debugURL.Path = "/"
+	}
+	if debugURL.Path != "/" {
+		return nil, coreerr.E("CDPClient.parseDebugURL", "debug URL must point at the DevTools root", nil)
+	}
+	return debugURL, nil
+}
+
+func canonicalDebugURL(debugURL *url.URL) string {
+	return core.TrimSuffix(debugURL.String(), "/")
+}
+
+func doDebugRequest(ctx context.Context, debugBase *url.URL, endpoint, rawQuery string) ([]byte, error) {
+	reqURL := *debugBase
+	reqURL.Path = endpoint
+	reqURL.RawPath = ""
+	reqURL.RawQuery = rawQuery
+	reqURL.Fragment = ""
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, reqURL.String(), nil)
+	if err != nil {
+		return nil, err
+	}
+
+	resp, err := defaultDebugHTTPClient.Do(req)
+	if err != nil {
+		return nil, err
 	}
 	defer func() { _ = resp.Body.Close() }()
 
 	body, err := io.ReadAll(resp.Body)
 	if err != nil {
-		return nil, fmt.Errorf("failed to read version: %w", err)
+		return nil, err
+	}
+	if resp.StatusCode < http.StatusOK || resp.StatusCode >= http.StatusMultipleChoices {
+		return nil, coreerr.E("CDPClient.doDebugRequest", "debug endpoint returned "+resp.Status, nil)
 	}
 
-	var version map[string]string
-	if err := json.Unmarshal(body, &version); err != nil {
-		return nil, fmt.Errorf("failed to parse version: %w", err)
-	}
-
-	return version, nil
+	return body, nil
+}
+
+func listTargetsAt(ctx context.Context, debugBase *url.URL) ([]TargetInfo, error) {
+	body, err := doDebugRequest(ctx, debugBase, "/json", "")
+	if err != nil {
+		return nil, err
+	}
+
+	var targets []TargetInfo
+	if r := core.JSONUnmarshal(body, &targets); !r.OK {
+		return nil, coreerr.E("CDPClient.listTargetsAt", "failed to parse targets", nil)
+	}
+
+	return targets, nil
+}
+
+func createTargetAt(ctx context.Context, debugBase *url.URL, pageURL string) (*TargetInfo, error) {
+	rawQuery := ""
+	if pageURL != "" {
+		rawQuery = url.QueryEscape(pageURL)
+	}
+
+	body, err := doDebugRequest(ctx, debugBase, "/json/new", rawQuery)
+	if err != nil {
+		return nil, err
+	}
+
+	var target TargetInfo
+	if r := core.JSONUnmarshal(body, &target); !r.OK {
+		return nil, coreerr.E("CDPClient.createTargetAt", "failed to parse target", nil)
+	}
+
+	return &target, nil
+}
+
+func validateTargetWebSocketURL(debugBase *url.URL, raw string) (string, error) {
+	wsURL, err := url.Parse(raw)
+	if err != nil {
+		return "", err
+	}
+	if wsURL.Scheme != "ws" && wsURL.Scheme != "wss" {
+		return "", coreerr.E("CDPClient.validateTargetWebSocketURL", "target WebSocket URL must use ws or wss", nil)
+	}
+	if !sameEndpointHost(debugBase, wsURL) {
+		return "", coreerr.E("CDPClient.validateTargetWebSocketURL", "target WebSocket URL must match debug URL host", nil)
+	}
+	return wsURL.String(), nil
+}
+
+func sameEndpointHost(httpURL, wsURL *url.URL) bool {
+	return strings.EqualFold(httpURL.Hostname(), wsURL.Hostname()) && normalisedPort(httpURL) == normalisedPort(wsURL)
+}
+
+func normalisedPort(u *url.URL) string {
+	if port := u.Port(); port != "" {
+		return port
+	}
+
+	switch u.Scheme {
+	case "http", "ws":
+		return "80"
+	case "https", "wss":
+		return "443"
+	default:
+		return ""
+	}
+}
+
+func targetIDFromWebSocketURL(raw string) (string, error) {
+	wsURL, err := url.Parse(raw)
+	if err != nil {
+		return "", err
+	}
+
+	targetID := path.Base(core.TrimSuffix(wsURL.Path, "/"))
+	if targetID == "." || targetID == "/" || targetID == "" {
+		return "", coreerr.E("CDPClient.targetIDFromWebSocketURL", "missing target ID in WebSocket URL", nil)
+	}
+
+	return targetID, nil
+}
+
+func (c *CDPClient) close(reason error) {
+	c.closeOnce.Do(func() {
+		c.cancel()
+		c.failPending(reason)
+
+		c.mu.Lock()
+		err := c.conn.Close()
+		c.mu.Unlock()
+		if err != nil && !isTerminalReadError(err) {
+			c.closeErr = err
+		}
+	})
+}
+
+func (c *CDPClient) failPending(err error) {
+	c.pendMu.Lock()
+	defer c.pendMu.Unlock()
+
+	for id, ch := range c.pending {
+		resp := &cdpResponse{
+			ID: id,
+			Error: &cdpError{
+				Message: err.Error(),
+			},
+		}
+		select {
+		case ch <- resp:
+		default:
+		}
+	}
+}
+
+func isTerminalReadError(err error) bool {
+	if err == nil {
+		return false
+	}
+	if core.Is(err, net.ErrClosed) || core.Is(err, websocket.ErrCloseSent) {
+		return true
+	}
+	var closeErr *websocket.CloseError
+	return core.As(err, &closeErr)
+}
+
+func cloneMapAny(src map[string]any) map[string]any {
+	if src == nil {
+		return nil
+	}
+
+	dst := make(map[string]any, len(src))
+	for key, value := range src {
+		dst[key] = cloneAny(value)
+	}
+	return dst
+}
+
+func cloneSliceAny(src []any) []any {
+	if src == nil {
+		return nil
+	}
+
+	dst := make([]any, len(src))
+	for i, value := range src {
+		dst[i] = cloneAny(value)
+	}
+	return dst
+}
+
+func cloneAny(value any) any {
+	switch typed := value.(type) {
+	case map[string]any:
+		return cloneMapAny(typed)
+	case []any:
+		return cloneSliceAny(typed)
+	default:
+		return typed
+	}
 }

console.go

@@ -1,23 +1,26 @@
+// SPDX-License-Identifier: EUPL-1.2
 package webview
 
 import (
 	"context"
-	"fmt"
 	"iter"
 	"slices"
-	"strings"
 	"sync"
+	"sync/atomic"
 	"time"
+
+	core "dappco.re/go/core"
 )
 
 // ConsoleWatcher provides advanced console message watching capabilities.
 type ConsoleWatcher struct {
-	mu       sync.RWMutex
-	wv       *Webview
-	messages []ConsoleMessage
-	filters  []ConsoleFilter
-	limit    int
-	handlers []ConsoleHandler
+	mu            sync.RWMutex
+	wv            *Webview
+	messages      []ConsoleMessage
+	filters       []ConsoleFilter
+	limit         int
+	handlers      []consoleHandlerRegistration
+	nextHandlerID atomic.Int64
 }
 
 // ConsoleFilter filters console messages.
@@ -29,14 +32,19 @@ type ConsoleFilter struct {
 // ConsoleHandler is called when a matching console message is received.
 type ConsoleHandler func(msg ConsoleMessage)
 
+type consoleHandlerRegistration struct {
+	id      int64
+	handler ConsoleHandler
+}
+
 // NewConsoleWatcher creates a new console watcher for the webview.
 func NewConsoleWatcher(wv *Webview) *ConsoleWatcher {
 	cw := &ConsoleWatcher{
 		wv:       wv,
-		messages: make([]ConsoleMessage, 0, 100),
+		messages: make([]ConsoleMessage, 0, 1000),
 		filters:  make([]ConsoleFilter, 0),
 		limit:    1000,
-		handlers: make([]ConsoleHandler, 0),
+		handlers: make([]consoleHandlerRegistration, 0),
 	}
 
 	// Subscribe to console events from the webview's client
@@ -63,9 +71,30 @@ func (cw *ConsoleWatcher) ClearFilters() {
 
 // AddHandler adds a handler for console messages.
 func (cw *ConsoleWatcher) AddHandler(handler ConsoleHandler) {
+	cw.addHandler(handler)
+}
+
+func (cw *ConsoleWatcher) addHandler(handler ConsoleHandler) int64 {
 	cw.mu.Lock()
 	defer cw.mu.Unlock()
-	cw.handlers = append(cw.handlers, handler)
+	id := cw.nextHandlerID.Add(1)
+	cw.handlers = append(cw.handlers, consoleHandlerRegistration{
+		id:      id,
+		handler: handler,
+	})
+	return id
+}
+
+func (cw *ConsoleWatcher) removeHandler(id int64) {
+	cw.mu.Lock()
+	defer cw.mu.Unlock()
+
+	for i, registration := range cw.handlers {
+		if registration.id == id {
+			cw.handlers = slices.Delete(cw.handlers, i, i+1)
+			return
+		}
+	}
 }
 
 // SetLimit sets the maximum number of messages to retain.
@@ -187,13 +216,8 @@ func (cw *ConsoleWatcher) WaitForMessage(ctx context.Context, filter ConsoleFilt
 		}
 	}
 
-	cw.AddHandler(handler)
-	defer func() {
-		cw.mu.Lock()
-		// Remove handler (simple implementation - in production you'd want a handle-based removal)
-		cw.handlers = cw.handlers[:len(cw.handlers)-1]
-		cw.mu.Unlock()
-	}()
+	handlerID := cw.addHandler(handler)
+	defer cw.removeHandler(handlerID)
 
 	select {
 	case <-ctx.Done():
@@ -248,14 +272,14 @@ func (cw *ConsoleWatcher) handleConsoleEvent(params map[string]any) {
 
 	// Extract args
 	args, _ := params["args"].([]any)
-	var text strings.Builder
+	text := core.NewBuilder()
 	for i, arg := range args {
 		if argMap, ok := arg.(map[string]any); ok {
 			if val, ok := argMap["value"]; ok {
 				if i > 0 {
 					text.WriteString(" ")
 				}
-				text.WriteString(fmt.Sprint(val))
+				text.WriteString(core.Sprint(val))
 			}
 		}
 	}
@@ -292,7 +316,8 @@ func (cw *ConsoleWatcher) addMessage(msg ConsoleMessage) {
 
 	// Enforce limit
 	if len(cw.messages) >= cw.limit {
-		cw.messages = cw.messages[len(cw.messages)-cw.limit+100:]
+		drop := min(100, len(cw.messages))
+		cw.messages = cw.messages[drop:]
 	}
 	cw.messages = append(cw.messages, msg)
 
@@ -301,8 +326,8 @@ func (cw *ConsoleWatcher) addMessage(msg ConsoleMessage) {
 	cw.mu.Unlock()
 
 	// Call handlers
-	for _, handler := range handlers {
-		handler(msg)
+	for _, registration := range handlers {
+		registration.handler(msg)
 	}
 }
 
@@ -360,10 +385,16 @@ type ExceptionInfo struct {
 
 // ExceptionWatcher watches for JavaScript exceptions.
 type ExceptionWatcher struct {
-	mu         sync.RWMutex
-	wv         *Webview
-	exceptions []ExceptionInfo
-	handlers   []func(ExceptionInfo)
+	mu            sync.RWMutex
+	wv            *Webview
+	exceptions    []ExceptionInfo
+	handlers      []exceptionHandlerRegistration
+	nextHandlerID atomic.Int64
+}
+
+type exceptionHandlerRegistration struct {
+	id      int64
+	handler func(ExceptionInfo)
 }
 
 // NewExceptionWatcher creates a new exception watcher.
@@ -371,7 +402,7 @@ func NewExceptionWatcher(wv *Webview) *ExceptionWatcher {
 	ew := &ExceptionWatcher{
 		wv:         wv,
 		exceptions: make([]ExceptionInfo, 0),
-		handlers:   make([]func(ExceptionInfo), 0),
+		handlers:   make([]exceptionHandlerRegistration, 0),
 	}
 
 	// Subscribe to exception events
@@ -424,9 +455,30 @@ func (ew *ExceptionWatcher) Count() int {
 
 // AddHandler adds a handler for exceptions.
 func (ew *ExceptionWatcher) AddHandler(handler func(ExceptionInfo)) {
+	ew.addHandler(handler)
+}
+
+func (ew *ExceptionWatcher) addHandler(handler func(ExceptionInfo)) int64 {
 	ew.mu.Lock()
 	defer ew.mu.Unlock()
-	ew.handlers = append(ew.handlers, handler)
+	id := ew.nextHandlerID.Add(1)
+	ew.handlers = append(ew.handlers, exceptionHandlerRegistration{
+		id:      id,
+		handler: handler,
+	})
+	return id
+}
+
+func (ew *ExceptionWatcher) removeHandler(id int64) {
+	ew.mu.Lock()
+	defer ew.mu.Unlock()
+
+	for i, registration := range ew.handlers {
+		if registration.id == id {
+			ew.handlers = slices.Delete(ew.handlers, i, i+1)
+			return
+		}
+	}
 }
 
 // WaitForException waits for an exception to be thrown.
@@ -449,12 +501,8 @@ func (ew *ExceptionWatcher) WaitForException(ctx context.Context) (*ExceptionInf
 		}
 	}
 
-	ew.AddHandler(handler)
-	defer func() {
-		ew.mu.Lock()
-		ew.handlers = ew.handlers[:len(ew.handlers)-1]
-		ew.mu.Unlock()
-	}()
+	handlerID := ew.addHandler(handler)
+	defer ew.removeHandler(handlerID)
 
 	select {
 	case <-ctx.Done():
@@ -477,7 +525,7 @@ func (ew *ExceptionWatcher) handleException(params map[string]any) {
 	url, _ := exceptionDetails["url"].(string)
 
 	// Extract stack trace
-	var stackTrace strings.Builder
+	stackTrace := core.NewBuilder()
 	if st, ok := exceptionDetails["stackTrace"].(map[string]any); ok {
 		if frames, ok := st["callFrames"].([]any); ok {
 			for _, f := range frames {
@@ -486,7 +534,7 @@ func (ew *ExceptionWatcher) handleException(params map[string]any) {
 					frameURL, _ := frame["url"].(string)
 					frameLine, _ := frame["lineNumber"].(float64)
 					frameCol, _ := frame["columnNumber"].(float64)
-					stackTrace.WriteString(fmt.Sprintf("  at %s (%s:%d:%d)\n", funcName, frameURL, int(frameLine), int(frameCol)))
+					stackTrace.WriteString(core.Sprintf("  at %s (%s:%d:%d)\n", funcName, frameURL, int(frameLine), int(frameCol)))
 				}
 			}
 		}
@@ -514,14 +562,14 @@ func (ew *ExceptionWatcher) handleException(params map[string]any) {
 	ew.mu.Unlock()
 
 	// Call handlers
-	for _, handler := range handlers {
-		handler(info)
+	for _, registration := range handlers {
+		registration.handler(info)
 	}
 }
 
 // FormatConsoleOutput formats console messages for display.
 func FormatConsoleOutput(messages []ConsoleMessage) string {
-	var output strings.Builder
+	output := core.NewBuilder()
 	for _, msg := range messages {
 		prefix := ""
 		switch msg.Type {
@@ -537,7 +585,7 @@ func FormatConsoleOutput(messages []ConsoleMessage) string {
 			prefix = "[LOG]"
 		}
 		timestamp := msg.Timestamp.Format("15:04:05.000")
-		output.WriteString(fmt.Sprintf("%s %s %s\n", timestamp, prefix, msg.Text))
+		output.WriteString(core.Sprintf("%s %s %s\n", timestamp, prefix, msg.Text))
 	}
 	return output.String()
 }

docs/api-contract.md

@@ -0,0 +1,160 @@
+---
+title: API Contract
+description: Extracted exported API contract for go-webview with signatures and test coverage notes.
+---
+
+# API Contract
+
+This inventory covers the current exported surface of `dappco.re/go/core/webview`.
+
+Coverage notes:
+- Coverage is based on `webview_test.go`.
+- `Indirect via ...` means the symbol is only exercised through another exported API or helper path.
+- `None` means no evidence was found in the current test file.
+
+| Kind | Name | Signature | Description | Test coverage |
+| --- | --- | --- | --- | --- |
+| Function | `FormatConsoleOutput` | `func FormatConsoleOutput(messages []ConsoleMessage) string` | FormatConsoleOutput formats console messages for display. | `TestFormatConsoleOutput_Good`, `TestFormatConsoleOutput_Good_Empty`. |
+| Function | `GetVersion` | `func GetVersion(debugURL string) (map[string]string, error)` | GetVersion returns Chrome version information. | None in `webview_test.go`. |
+| Function | `ListTargetsAll` | `func ListTargetsAll(debugURL string) iter.Seq[TargetInfo]` | ListTargetsAll returns an iterator over all available targets. | None in `webview_test.go`. |
+| Type | `Action` | `type Action interface { Execute(ctx context.Context, wv *Webview) error }` | Action represents a browser action that can be performed. | Indirect via `TestActionSequence_Good`, `TestWaitAction_Good_ContextCancelled`, and `TestWaitAction_Good_ShortWait`. |
+| Method | `Action.Execute` | `Execute(ctx context.Context, wv *Webview) error` | Runs an action against a Webview within the caller's context. | Indirect via `TestWaitAction_Good_ContextCancelled` and `TestWaitAction_Good_ShortWait`. |
+| Type | `ActionSequence` | `type ActionSequence struct { /* unexported fields */ }` | ActionSequence represents a sequence of actions to execute. | `TestActionSequence_Good`. |
+| Function | `NewActionSequence` | `func NewActionSequence() *ActionSequence` | NewActionSequence creates a new action sequence. | `TestActionSequence_Good`. |
+| Method | `ActionSequence.Add` | `func (s *ActionSequence) Add(action Action) *ActionSequence` | Add adds an action to the sequence. | Indirect via `TestActionSequence_Good` builder chaining. |
+| Method | `ActionSequence.Click` | `func (s *ActionSequence) Click(selector string) *ActionSequence` | Click adds a click action. | `TestActionSequence_Good`. |
+| Method | `ActionSequence.Execute` | `func (s *ActionSequence) Execute(ctx context.Context, wv *Webview) error` | Execute executes all actions in the sequence. | None in `webview_test.go`. |
+| Method | `ActionSequence.Navigate` | `func (s *ActionSequence) Navigate(url string) *ActionSequence` | Navigate adds a navigate action. | `TestActionSequence_Good`. |
+| Method | `ActionSequence.Type` | `func (s *ActionSequence) Type(selector, text string) *ActionSequence` | Type adds a type action. | `TestActionSequence_Good`. |
+| Method | `ActionSequence.Wait` | `func (s *ActionSequence) Wait(d time.Duration) *ActionSequence` | Wait adds a wait action. | `TestActionSequence_Good`. |
+| Method | `ActionSequence.WaitForSelector` | `func (s *ActionSequence) WaitForSelector(selector string) *ActionSequence` | WaitForSelector adds a wait for selector action. | `TestActionSequence_Good`. |
+| Type | `AngularHelper` | `type AngularHelper struct { /* unexported fields */ }` | AngularHelper provides Angular-specific testing utilities. | None in `webview_test.go`. |
+| Function | `NewAngularHelper` | `func NewAngularHelper(wv *Webview) *AngularHelper` | NewAngularHelper creates a new Angular helper for the webview. | None in `webview_test.go`. |
+| Method | `AngularHelper.CallComponentMethod` | `func (ah *AngularHelper) CallComponentMethod(selector, methodName string, args ...any) (any, error)` | CallComponentMethod calls a method on an Angular component. | None in `webview_test.go`. |
+| Method | `AngularHelper.DispatchEvent` | `func (ah *AngularHelper) DispatchEvent(selector, eventName string, detail any) error` | DispatchEvent dispatches a custom event on an element. | None in `webview_test.go`. |
+| Method | `AngularHelper.GetComponentProperty` | `func (ah *AngularHelper) GetComponentProperty(selector, propertyName string) (any, error)` | GetComponentProperty gets a property from an Angular component. | None in `webview_test.go`. |
+| Method | `AngularHelper.GetNgModel` | `func (ah *AngularHelper) GetNgModel(selector string) (any, error)` | GetNgModel gets the value of an ngModel-bound input. | None in `webview_test.go`. |
+| Method | `AngularHelper.GetRouterState` | `func (ah *AngularHelper) GetRouterState() (*AngularRouterState, error)` | GetRouterState returns the current Angular router state. | None in `webview_test.go`. |
+| Method | `AngularHelper.GetService` | `func (ah *AngularHelper) GetService(serviceName string) (any, error)` | GetService gets an Angular service by token name. | None in `webview_test.go`. |
+| Method | `AngularHelper.NavigateByRouter` | `func (ah *AngularHelper) NavigateByRouter(path string) error` | NavigateByRouter navigates using Angular Router. | None in `webview_test.go`. |
+| Method | `AngularHelper.SetComponentProperty` | `func (ah *AngularHelper) SetComponentProperty(selector, propertyName string, value any) error` | SetComponentProperty sets a property on an Angular component. | None in `webview_test.go`. |
+| Method | `AngularHelper.SetNgModel` | `func (ah *AngularHelper) SetNgModel(selector string, value any) error` | SetNgModel sets the value of an ngModel-bound input. | None in `webview_test.go`. |
+| Method | `AngularHelper.SetTimeout` | `func (ah *AngularHelper) SetTimeout(d time.Duration)` | SetTimeout sets the default timeout for Angular operations. | None in `webview_test.go`. |
+| Method | `AngularHelper.TriggerChangeDetection` | `func (ah *AngularHelper) TriggerChangeDetection() error` | TriggerChangeDetection manually triggers Angular change detection. | None in `webview_test.go`. |
+| Method | `AngularHelper.WaitForAngular` | `func (ah *AngularHelper) WaitForAngular() error` | WaitForAngular waits for Angular to finish all pending operations. | None in `webview_test.go`. |
+| Method | `AngularHelper.WaitForComponent` | `func (ah *AngularHelper) WaitForComponent(selector string) error` | WaitForComponent waits for an Angular component to be present. | None in `webview_test.go`. |
+| Type | `AngularRouterState` | `type AngularRouterState struct { URL string Fragment string Params map[string]string QueryParams map[string]string }` | AngularRouterState represents Angular router state. | `TestAngularRouterState_Good`. |
+| Type | `BlurAction` | `type BlurAction struct { Selector string }` | BlurAction removes focus from an element. | `TestBlurAction_Good`. |
+| Method | `BlurAction.Execute` | `func (a BlurAction) Execute(ctx context.Context, wv *Webview) error` | Execute removes focus from the element. | None in `webview_test.go`. |
+| Type | `BoundingBox` | `type BoundingBox struct { X float64 Y float64 Width float64 Height float64 }` | BoundingBox represents the bounding rectangle of an element. | `TestBoundingBox_Good`; also nested in `TestElementInfo_Good`. |
+| Type | `CDPClient` | `type CDPClient struct { /* unexported fields */ }` | CDPClient handles communication with Chrome DevTools Protocol via WebSocket. | None in `webview_test.go`. |
+| Function | `NewCDPClient` | `func NewCDPClient(debugURL string) (*CDPClient, error)` | NewCDPClient creates a new CDP client connected to the given debug URL. | Indirect error-path coverage via `TestNew_Bad_InvalidDebugURL`. |
+| Method | `CDPClient.Call` | `func (c *CDPClient) Call(ctx context.Context, method string, params map[string]any) (map[string]any, error)` | Call sends a CDP method call and waits for the response. | None in `webview_test.go`. |
+| Method | `CDPClient.Close` | `func (c *CDPClient) Close() error` | Close closes the CDP connection. | None in `webview_test.go`. |
+| Method | `CDPClient.CloseTab` | `func (c *CDPClient) CloseTab() error` | CloseTab closes the current tab (target). | None in `webview_test.go`. |
+| Method | `CDPClient.DebugURL` | `func (c *CDPClient) DebugURL() string` | DebugURL returns the debug HTTP URL. | None in `webview_test.go`. |
+| Method | `CDPClient.NewTab` | `func (c *CDPClient) NewTab(url string) (*CDPClient, error)` | NewTab creates a new browser tab and returns a new CDPClient connected to it. | None in `webview_test.go`. |
+| Method | `CDPClient.OnEvent` | `func (c *CDPClient) OnEvent(method string, handler func(map[string]any))` | OnEvent registers a handler for CDP events. | None in `webview_test.go`. |
+| Method | `CDPClient.Send` | `func (c *CDPClient) Send(method string, params map[string]any) error` | Send sends a fire-and-forget CDP message (no response expected). | None in `webview_test.go`. |
+| Method | `CDPClient.WebSocketURL` | `func (c *CDPClient) WebSocketURL() string` | WebSocketURL returns the WebSocket URL being used. | None in `webview_test.go`. |
+| Type | `CheckAction` | `type CheckAction struct { Selector string Checked bool }` | CheckAction checks or unchecks a checkbox. | `TestCheckAction_Good`. |
+| Method | `CheckAction.Execute` | `func (a CheckAction) Execute(ctx context.Context, wv *Webview) error` | Execute checks/unchecks the checkbox. | None in `webview_test.go`. |
+| Type | `ClearAction` | `type ClearAction struct { Selector string }` | ClearAction clears the value of an input element. | `TestClearAction_Good`. |
+| Method | `ClearAction.Execute` | `func (a ClearAction) Execute(ctx context.Context, wv *Webview) error` | Execute clears the input value. | None in `webview_test.go`. |
+| Type | `ClickAction` | `type ClickAction struct { Selector string }` | ClickAction represents a click action. | `TestClickAction_Good`. |
+| Method | `ClickAction.Execute` | `func (a ClickAction) Execute(ctx context.Context, wv *Webview) error` | Execute performs the click action. | None in `webview_test.go`. |
+| Type | `ConsoleFilter` | `type ConsoleFilter struct { Type string Pattern string }` | ConsoleFilter filters console messages. | `TestConsoleWatcherFilter_Good`, `TestConsoleWatcherFilteredMessages_Good`. |
+| Type | `ConsoleHandler` | `type ConsoleHandler func(msg ConsoleMessage)` | ConsoleHandler is called when a matching console message is received. | Indirect via `TestConsoleWatcherHandler_Good`. |
+| Type | `ConsoleMessage` | `type ConsoleMessage struct { Type string Text string Timestamp time.Time URL string Line int Column int }` | ConsoleMessage represents a captured console log message. | `TestConsoleMessage_Good`; also used by console watcher tests. |
+| Type | `ConsoleWatcher` | `type ConsoleWatcher struct { /* unexported fields */ }` | ConsoleWatcher provides advanced console message watching capabilities. | `TestConsoleWatcherFilter_Good`, `TestConsoleWatcherCounts_Good`, `TestConsoleWatcherAddMessage_Good`, `TestConsoleWatcherHandler_Good`, `TestConsoleWatcherFilteredMessages_Good`. |
+| Function | `NewConsoleWatcher` | `func NewConsoleWatcher(wv *Webview) *ConsoleWatcher` | NewConsoleWatcher creates a new console watcher for the webview. | None in `webview_test.go`. |
+| Method | `ConsoleWatcher.AddFilter` | `func (cw *ConsoleWatcher) AddFilter(filter ConsoleFilter)` | AddFilter adds a filter to the watcher. | `TestConsoleWatcherFilter_Good`. |
+| Method | `ConsoleWatcher.AddHandler` | `func (cw *ConsoleWatcher) AddHandler(handler ConsoleHandler)` | AddHandler adds a handler for console messages. | `TestConsoleWatcherHandler_Good`. |
+| Method | `ConsoleWatcher.Clear` | `func (cw *ConsoleWatcher) Clear()` | Clear clears all captured messages. | `TestConsoleWatcherCounts_Good`. |
+| Method | `ConsoleWatcher.ClearFilters` | `func (cw *ConsoleWatcher) ClearFilters()` | ClearFilters removes all filters. | `TestConsoleWatcherFilter_Good`. |
+| Method | `ConsoleWatcher.Count` | `func (cw *ConsoleWatcher) Count() int` | Count returns the number of captured messages. | `TestConsoleWatcherCounts_Good`. |
+| Method | `ConsoleWatcher.ErrorCount` | `func (cw *ConsoleWatcher) ErrorCount() int` | ErrorCount returns the number of error messages. | `TestConsoleWatcherCounts_Good`. |
+| Method | `ConsoleWatcher.Errors` | `func (cw *ConsoleWatcher) Errors() []ConsoleMessage` | Errors returns all error messages. | `TestConsoleWatcherCounts_Good`. |
+| Method | `ConsoleWatcher.ErrorsAll` | `func (cw *ConsoleWatcher) ErrorsAll() iter.Seq[ConsoleMessage]` | ErrorsAll returns an iterator over all error messages. | Indirect via `ConsoleWatcher.Errors()` in `TestConsoleWatcherCounts_Good`. |
+| Method | `ConsoleWatcher.FilteredMessages` | `func (cw *ConsoleWatcher) FilteredMessages() []ConsoleMessage` | FilteredMessages returns messages matching the current filters. | `TestConsoleWatcherFilteredMessages_Good`. |
+| Method | `ConsoleWatcher.FilteredMessagesAll` | `func (cw *ConsoleWatcher) FilteredMessagesAll() iter.Seq[ConsoleMessage]` | FilteredMessagesAll returns an iterator over messages matching the current filters. | Indirect via `ConsoleWatcher.FilteredMessages()` in `TestConsoleWatcherFilteredMessages_Good`. |
+| Method | `ConsoleWatcher.HasErrors` | `func (cw *ConsoleWatcher) HasErrors() bool` | HasErrors returns true if there are any error messages. | `TestConsoleWatcherCounts_Good`. |
+| Method | `ConsoleWatcher.Messages` | `func (cw *ConsoleWatcher) Messages() []ConsoleMessage` | Messages returns all captured messages. | None in `webview_test.go`. |
+| Method | `ConsoleWatcher.MessagesAll` | `func (cw *ConsoleWatcher) MessagesAll() iter.Seq[ConsoleMessage]` | MessagesAll returns an iterator over all captured messages. | None in `webview_test.go`. |
+| Method | `ConsoleWatcher.SetLimit` | `func (cw *ConsoleWatcher) SetLimit(limit int)` | SetLimit sets the maximum number of messages to retain. | None in `webview_test.go`. |
+| Method | `ConsoleWatcher.WaitForError` | `func (cw *ConsoleWatcher) WaitForError(ctx context.Context) (*ConsoleMessage, error)` | WaitForError waits for an error message. | None in `webview_test.go`. |
+| Method | `ConsoleWatcher.WaitForMessage` | `func (cw *ConsoleWatcher) WaitForMessage(ctx context.Context, filter ConsoleFilter) (*ConsoleMessage, error)` | WaitForMessage waits for a message matching the filter. | None in `webview_test.go`. |
+| Method | `ConsoleWatcher.Warnings` | `func (cw *ConsoleWatcher) Warnings() []ConsoleMessage` | Warnings returns all warning messages. | `TestConsoleWatcherCounts_Good`. |
+| Method | `ConsoleWatcher.WarningsAll` | `func (cw *ConsoleWatcher) WarningsAll() iter.Seq[ConsoleMessage]` | WarningsAll returns an iterator over all warning messages. | Indirect via `ConsoleWatcher.Warnings()` in `TestConsoleWatcherCounts_Good`. |
+| Type | `DoubleClickAction` | `type DoubleClickAction struct { Selector string }` | DoubleClickAction double-clicks an element. | `TestDoubleClickAction_Good`. |
+| Method | `DoubleClickAction.Execute` | `func (a DoubleClickAction) Execute(ctx context.Context, wv *Webview) error` | Execute double-clicks the element. | None in `webview_test.go`. |
+| Type | `ElementInfo` | `type ElementInfo struct { NodeID int TagName string Attributes map[string]string InnerHTML string InnerText string BoundingBox *BoundingBox }` | ElementInfo represents information about a DOM element. | `TestElementInfo_Good`. |
+| Type | `ExceptionInfo` | `type ExceptionInfo struct { Text string LineNumber int ColumnNumber int URL string StackTrace string Timestamp time.Time }` | ExceptionInfo represents information about a JavaScript exception. | `TestExceptionInfo_Good`; also used by `TestExceptionWatcher_Good`. |
+| Type | `ExceptionWatcher` | `type ExceptionWatcher struct { /* unexported fields */ }` | ExceptionWatcher watches for JavaScript exceptions. | `TestExceptionWatcher_Good`. |
+| Function | `NewExceptionWatcher` | `func NewExceptionWatcher(wv *Webview) *ExceptionWatcher` | NewExceptionWatcher creates a new exception watcher. | None in `webview_test.go`. |
+| Method | `ExceptionWatcher.AddHandler` | `func (ew *ExceptionWatcher) AddHandler(handler func(ExceptionInfo))` | AddHandler adds a handler for exceptions. | None in `webview_test.go`. |
+| Method | `ExceptionWatcher.Clear` | `func (ew *ExceptionWatcher) Clear()` | Clear clears all captured exceptions. | `TestExceptionWatcher_Good`. |
+| Method | `ExceptionWatcher.Count` | `func (ew *ExceptionWatcher) Count() int` | Count returns the number of exceptions. | `TestExceptionWatcher_Good`. |
+| Method | `ExceptionWatcher.Exceptions` | `func (ew *ExceptionWatcher) Exceptions() []ExceptionInfo` | Exceptions returns all captured exceptions. | `TestExceptionWatcher_Good`. |
+| Method | `ExceptionWatcher.ExceptionsAll` | `func (ew *ExceptionWatcher) ExceptionsAll() iter.Seq[ExceptionInfo]` | ExceptionsAll returns an iterator over all captured exceptions. | Indirect via `ExceptionWatcher.Exceptions()` in `TestExceptionWatcher_Good`. |
+| Method | `ExceptionWatcher.HasExceptions` | `func (ew *ExceptionWatcher) HasExceptions() bool` | HasExceptions returns true if there are any exceptions. | `TestExceptionWatcher_Good`. |
+| Method | `ExceptionWatcher.WaitForException` | `func (ew *ExceptionWatcher) WaitForException(ctx context.Context) (*ExceptionInfo, error)` | WaitForException waits for an exception to be thrown. | None in `webview_test.go`. |
+| Type | `FocusAction` | `type FocusAction struct { Selector string }` | FocusAction focuses an element. | `TestFocusAction_Good`. |
+| Method | `FocusAction.Execute` | `func (a FocusAction) Execute(ctx context.Context, wv *Webview) error` | Execute focuses the element. | None in `webview_test.go`. |
+| Type | `HoverAction` | `type HoverAction struct { Selector string }` | HoverAction hovers over an element. | `TestHoverAction_Good`. |
+| Method | `HoverAction.Execute` | `func (a HoverAction) Execute(ctx context.Context, wv *Webview) error` | Execute hovers over the element. | None in `webview_test.go`. |
+| Type | `NavigateAction` | `type NavigateAction struct { URL string }` | NavigateAction represents a navigation action. | `TestNavigateAction_Good`. |
+| Method | `NavigateAction.Execute` | `func (a NavigateAction) Execute(ctx context.Context, wv *Webview) error` | Execute performs the navigate action. | None in `webview_test.go`. |
+| Type | `Option` | `type Option func(*Webview) error` | Option configures a Webview instance. | Used in `TestWithTimeout_Good`, `TestWithConsoleLimit_Good`, and `TestNew_Bad_InvalidDebugURL`. |
+| Function | `WithConsoleLimit` | `func WithConsoleLimit(limit int) Option` | WithConsoleLimit sets the maximum number of console messages to retain. | `TestWithConsoleLimit_Good`. |
+| Function | `WithDebugURL` | `func WithDebugURL(url string) Option` | WithDebugURL sets the Chrome DevTools debugging URL. | Indirect error-path coverage via `TestNew_Bad_InvalidDebugURL`. |
+| Function | `WithTimeout` | `func WithTimeout(d time.Duration) Option` | WithTimeout sets the default timeout for operations. | `TestWithTimeout_Good`. |
+| Type | `PressKeyAction` | `type PressKeyAction struct { Key string }` | PressKeyAction presses a key. | `TestPressKeyAction_Good`. |
+| Method | `PressKeyAction.Execute` | `func (a PressKeyAction) Execute(ctx context.Context, wv *Webview) error` | Execute presses the key. | None in `webview_test.go`. |
+| Type | `RemoveAttributeAction` | `type RemoveAttributeAction struct { Selector string Attribute string }` | RemoveAttributeAction removes an attribute from an element. | `TestRemoveAttributeAction_Good`. |
+| Method | `RemoveAttributeAction.Execute` | `func (a RemoveAttributeAction) Execute(ctx context.Context, wv *Webview) error` | Execute removes the attribute. | None in `webview_test.go`. |
+| Type | `RightClickAction` | `type RightClickAction struct { Selector string }` | RightClickAction right-clicks an element. | `TestRightClickAction_Good`. |
+| Method | `RightClickAction.Execute` | `func (a RightClickAction) Execute(ctx context.Context, wv *Webview) error` | Execute right-clicks the element. | None in `webview_test.go`. |
+| Type | `ScrollAction` | `type ScrollAction struct { X int Y int }` | ScrollAction represents a scroll action. | `TestScrollAction_Good`. |
+| Method | `ScrollAction.Execute` | `func (a ScrollAction) Execute(ctx context.Context, wv *Webview) error` | Execute performs the scroll action. | None in `webview_test.go`. |
+| Type | `ScrollIntoViewAction` | `type ScrollIntoViewAction struct { Selector string }` | ScrollIntoViewAction scrolls an element into view. | `TestScrollIntoViewAction_Good`. |
+| Method | `ScrollIntoViewAction.Execute` | `func (a ScrollIntoViewAction) Execute(ctx context.Context, wv *Webview) error` | Execute scrolls the element into view. | None in `webview_test.go`. |
+| Type | `SelectAction` | `type SelectAction struct { Selector string Value string }` | SelectAction selects an option in a select element. | `TestSelectAction_Good`. |
+| Method | `SelectAction.Execute` | `func (a SelectAction) Execute(ctx context.Context, wv *Webview) error` | Execute selects the option. | None in `webview_test.go`. |
+| Type | `SetAttributeAction` | `type SetAttributeAction struct { Selector string Attribute string Value string }` | SetAttributeAction sets an attribute on an element. | `TestSetAttributeAction_Good`. |
+| Method | `SetAttributeAction.Execute` | `func (a SetAttributeAction) Execute(ctx context.Context, wv *Webview) error` | Execute sets the attribute. | None in `webview_test.go`. |
+| Type | `SetValueAction` | `type SetValueAction struct { Selector string Value string }` | SetValueAction sets the value of an input element. | `TestSetValueAction_Good`. |
+| Method | `SetValueAction.Execute` | `func (a SetValueAction) Execute(ctx context.Context, wv *Webview) error` | Execute sets the value. | None in `webview_test.go`. |
+| Type | `TargetInfo` | `type TargetInfo struct { ID string Type string Title string URL string WebSocketDebuggerURL string }` | TargetInfo represents Chrome DevTools target information. | `TestTargetInfo_Good`. |
+| Function | `ListTargets` | `func ListTargets(debugURL string) ([]TargetInfo, error)` | ListTargets returns all available targets. | None in `webview_test.go`. |
+| Type | `TypeAction` | `type TypeAction struct { Selector string Text string }` | TypeAction represents a typing action. | `TestTypeAction_Good`. |
+| Method | `TypeAction.Execute` | `func (a TypeAction) Execute(ctx context.Context, wv *Webview) error` | Execute performs the type action. | None in `webview_test.go`. |
+| Type | `WaitAction` | `type WaitAction struct { Duration time.Duration }` | WaitAction represents a wait action. | `TestWaitAction_Good`, `TestWaitAction_Good_ContextCancelled`, `TestWaitAction_Good_ShortWait`. |
+| Method | `WaitAction.Execute` | `func (a WaitAction) Execute(ctx context.Context, wv *Webview) error` | Execute performs the wait action. | `TestWaitAction_Good_ContextCancelled`, `TestWaitAction_Good_ShortWait`. |
+| Type | `WaitForSelectorAction` | `type WaitForSelectorAction struct { Selector string }` | WaitForSelectorAction represents waiting for a selector. | `TestWaitForSelectorAction_Good`. |
+| Method | `WaitForSelectorAction.Execute` | `func (a WaitForSelectorAction) Execute(ctx context.Context, wv *Webview) error` | Execute waits for the selector to appear. | None in `webview_test.go`. |
+| Type | `Webview` | `type Webview struct { /* unexported fields */ }` | Webview represents a connection to a Chrome DevTools Protocol endpoint. | Structural coverage in `TestWithTimeout_Good`, `TestWithConsoleLimit_Good`, and `TestAddConsoleMessage_Good`; no public-method test. |
+| Function | `New` | `func New(opts ...Option) (*Webview, error)` | New creates a new Webview instance with the given options. | `TestNew_Bad_NoDebugURL`, `TestNew_Bad_InvalidDebugURL`. |
+| Method | `Webview.ClearConsole` | `func (wv *Webview) ClearConsole()` | ClearConsole clears captured console messages. | None in `webview_test.go`. |
+| Method | `Webview.Click` | `func (wv *Webview) Click(selector string) error` | Click clicks on an element matching the selector. | None in `webview_test.go`. |
+| Method | `Webview.Close` | `func (wv *Webview) Close() error` | Close closes the Webview connection. | None in `webview_test.go`. |
+| Method | `Webview.DragAndDrop` | `func (wv *Webview) DragAndDrop(sourceSelector, targetSelector string) error` | DragAndDrop performs a drag and drop operation. | None in `webview_test.go`. |
+| Method | `Webview.Evaluate` | `func (wv *Webview) Evaluate(script string) (any, error)` | Evaluate executes JavaScript and returns the result. | None in `webview_test.go`. |
+| Method | `Webview.GetConsole` | `func (wv *Webview) GetConsole() []ConsoleMessage` | GetConsole returns captured console messages. | None in `webview_test.go`. |
+| Method | `Webview.GetConsoleAll` | `func (wv *Webview) GetConsoleAll() iter.Seq[ConsoleMessage]` | GetConsoleAll returns an iterator over captured console messages. | None in `webview_test.go`. |
+| Method | `Webview.GetHTML` | `func (wv *Webview) GetHTML(selector string) (string, error)` | GetHTML returns the outer HTML of an element or the whole document. | None in `webview_test.go`. |
+| Method | `Webview.GetTitle` | `func (wv *Webview) GetTitle() (string, error)` | GetTitle returns the current page title. | None in `webview_test.go`. |
+| Method | `Webview.GetURL` | `func (wv *Webview) GetURL() (string, error)` | GetURL returns the current page URL. | None in `webview_test.go`. |
+| Method | `Webview.GoBack` | `func (wv *Webview) GoBack() error` | GoBack navigates back in history. | None in `webview_test.go`. |
+| Method | `Webview.GoForward` | `func (wv *Webview) GoForward() error` | GoForward navigates forward in history. | None in `webview_test.go`. |
+| Method | `Webview.Navigate` | `func (wv *Webview) Navigate(url string) error` | Navigate navigates to the specified URL. | None in `webview_test.go`. |
+| Method | `Webview.QuerySelector` | `func (wv *Webview) QuerySelector(selector string) (*ElementInfo, error)` | QuerySelector finds an element by CSS selector and returns its information. | None in `webview_test.go`. |
+| Method | `Webview.QuerySelectorAll` | `func (wv *Webview) QuerySelectorAll(selector string) ([]*ElementInfo, error)` | QuerySelectorAll finds all elements matching the selector. | None in `webview_test.go`. |
+| Method | `Webview.QuerySelectorAllAll` | `func (wv *Webview) QuerySelectorAllAll(selector string) iter.Seq[*ElementInfo]` | QuerySelectorAllAll returns an iterator over all elements matching the selector. | None in `webview_test.go`. |
+| Method | `Webview.Reload` | `func (wv *Webview) Reload() error` | Reload reloads the current page. | None in `webview_test.go`. |
+| Method | `Webview.Screenshot` | `func (wv *Webview) Screenshot() ([]byte, error)` | Screenshot captures a screenshot and returns it as PNG bytes. | None in `webview_test.go`. |
+| Method | `Webview.SetUserAgent` | `func (wv *Webview) SetUserAgent(userAgent string) error` | SetUserAgent sets the user agent string. | None in `webview_test.go`. |
+| Method | `Webview.SetViewport` | `func (wv *Webview) SetViewport(width, height int) error` | SetViewport sets the viewport size. | None in `webview_test.go`. |
+| Method | `Webview.Type` | `func (wv *Webview) Type(selector, text string) error` | Type types text into an element matching the selector. | None in `webview_test.go`. |
+| Method | `Webview.UploadFile` | `func (wv *Webview) UploadFile(selector string, filePaths []string) error` | UploadFile uploads a file to a file input element. | None in `webview_test.go`. |
+| Method | `Webview.WaitForSelector` | `func (wv *Webview) WaitForSelector(selector string) error` | WaitForSelector waits for an element matching the selector to appear. | None in `webview_test.go`. |

docs/architecture.md

@@ -1,45 +1,46 @@
+---
+title: Architecture
+description: Internals of go-webview -- CDP connection, message protocol, DOM queries, console capture, action system, and Angular helpers.
+---
+
 # Architecture
 
-Module: `forge.lthn.ai/core/go-webview`
+This document describes how `go-webview` works internally. It covers the CDP connection lifecycle, message protocol, DOM query mechanics, input simulation, console capture, the action system, Angular helpers, and thread safety.
 
-## Overview
+## High-Level Data Flow
 
-go-webview is a Chrome DevTools Protocol (CDP) client for browser automation, testing, and scraping. It provides a high-level Go API over the low-level CDP WebSocket protocol, connecting to an externally managed Chrome or Chromium instance running with the remote debugging port enabled.
+```
+Application Code
+      |
+      v
+  Webview  (high-level API: Navigate, Click, Type, Screenshot, ...)
+      |
+      v
+  CDPClient  (WebSocket transport, message framing, event dispatch)
+      |
+      v
+  Chrome / Chromium  (running with --remote-debugging-port=9222)
+```
 
-The package does not launch Chrome itself. The caller is responsible for starting a Chrome process with `--remote-debugging-port=9222` before constructing a `Webview`.
-
----
-
-## Package Structure
-
-| File | Responsibility |
-|------|---------------|
-| `webview.go` | `Webview` struct, public API, navigation, DOM, screenshot, JS evaluation |
-| `cdp.go` | `CDPClient` — WebSocket transport, message framing, event dispatch |
-| `actions.go` | `Action` interface, concrete action types, `ActionSequence` builder |
-| `console.go` | `ConsoleWatcher`, `ExceptionWatcher`, log formatting |
-| `angular.go` | `AngularHelper` — SPA-specific helpers for Angular 2+ and AngularJS 1.x |
-
----
+The application interacts with `Webview` methods. Each method constructs a CDP command, passes it to `CDPClient.Call()`, which serialises it as JSON over a WebSocket connection to Chrome. Chrome processes the command and returns a JSON response. Events (console messages, exceptions, navigation state changes) flow in the opposite direction: Chrome pushes them over the WebSocket, the `CDPClient` read loop dispatches them to registered handlers.
 
 ## CDP Connection
 
 ### Initialisation
 
-`NewCDPClient(debugURL string)` connects to Chrome's HTTP endpoint:
+`NewCDPClient(debugURL string)` connects to Chrome's HTTP endpoint in four steps:
 
 1. Issues `GET {debugURL}/json` to retrieve the list of available targets (tabs/pages).
 2. Selects the first target with `type == "page"` that has a `webSocketDebuggerUrl`.
 3. If no page target exists, calls `GET {debugURL}/json/new` to create one.
-4. Upgrades the connection to WebSocket using `github.com/gorilla/websocket`.
-5. Starts a background `readLoop` goroutine on the connection.
+4. Upgrades the connection to WebSocket using `github.com/gorilla/websocket` and starts a background `readLoop` goroutine.
 
 ### Message Protocol
 
 CDP uses JSON-framed messages over WebSocket. The client distinguishes two message kinds:
 
-- **Commands** — sent by the client with an integer `id`. Chrome responds with a matching `id` and a `result` or `error` field.
-- **Events** — sent by Chrome without an `id`. They carry a `method` name and a `params` map.
+- **Commands** -- sent by the client with an integer `id`. Chrome responds with a matching `id` and a `result` or `error` field.
+- **Events** -- sent by Chrome without an `id`. They carry a `method` name and a `params` map.
 
 The `CDPClient` maintains a `pending` map of `id -> chan *cdpResponse`. When `Call()` sends a command it registers a channel, then blocks on that channel until the matching response arrives or the context expires.
 
@@ -49,25 +50,42 @@ Events are dispatched to zero or more registered handlers via `OnEvent(method, h
 
 ```
 New(WithDebugURL(...))
-  └── NewCDPClient(url)
-        ├── HTTP GET /json          (target discovery)
-        ├── websocket.Dial(wsURL)   (WebSocket upgrade)
-        └── go readLoop()           (background goroutine)
+  +-- NewCDPClient(url)
+        |-- HTTP GET /json          (target discovery)
+        |-- websocket.Dial(wsURL)   (WebSocket upgrade)
+        +-- go readLoop()           (background goroutine)
 
 wv.Close()
-  └── cancel()                     (signals readLoop to stop)
-      └── CDPClient.Close()
-            ├── <-done              (waits for readLoop to finish)
-            └── conn.Close()        (closes WebSocket)
+  +-- cancel()                     (signals readLoop to stop)
+      +-- CDPClient.Close()
+            |-- <-done              (waits for readLoop to finish)
+            +-- conn.Close()        (closes WebSocket)
 ```
 
----
+## Key Types
 
-## Webview Struct
+### CDPClient
+
+```go
+type CDPClient struct {
+    conn     *websocket.Conn
+    debugURL string
+    wsURL    string
+    msgID    atomic.Int64                    // monotonic command ID
+    pending  map[int64]chan *cdpResponse      // awaiting responses
+    handlers map[string][]func(map[string]any) // event subscribers
+    ctx      context.Context
+    cancel   context.CancelFunc
+    done     chan struct{}
+}
+```
+
+The core transport layer. All WebSocket reads happen in the `readLoop` goroutine. All writes are serialised through a `sync.RWMutex`. The `pending` map and `handlers` map each have their own dedicated mutexes.
+
+### Webview
 
 ```go
 type Webview struct {
-    mu           sync.RWMutex
     client       *CDPClient
     ctx          context.Context
     cancel       context.CancelFunc
@@ -77,40 +95,22 @@ type Webview struct {
 }
 ```
 
-`New()` accepts functional options:
+The high-level API surface. Constructed via `New()` with functional options. On construction, it enables three CDP domains -- `Runtime`, `Page`, and `DOM` -- and registers a handler for `Runtime.consoleAPICalled` events so console capture begins immediately.
 
-| Option | Effect |
-|--------|--------|
-| `WithDebugURL(url)` | Required. Connects to Chrome at the given HTTP debug endpoint. |
-| `WithTimeout(d)` | Overrides the default 30-second operation timeout. |
-| `WithConsoleLimit(n)` | Maximum console messages to retain in memory (default 1000). |
+### ConsoleMessage
 
-On construction, `New()` enables three CDP domains — `Runtime`, `Page`, and `DOM` — and registers a handler for `Runtime.consoleAPICalled` events to begin console capture immediately.
+```go
+type ConsoleMessage struct {
+    Type      string    // log, warn, error, info, debug
+    Text      string    // message text
+    Timestamp time.Time
+    URL       string    // source URL
+    Line      int       // source line number
+    Column    int       // source column number
+}
+```
 
----
-
-## Navigation
-
-`Navigate(url string) error` calls `Page.navigate` then polls `document.readyState` via `Runtime.evaluate` at 100 ms intervals until the value is `"complete"` or the context deadline is exceeded.
-
-`Reload()`, `GoBack()`, and `GoForward()` follow the same pattern: issue a CDP command then call `waitForLoad`.
-
-`waitForSelector(ctx, selector)` polls `document.querySelector(selector)` at 100 ms intervals.
-
----
-
-## DOM Queries
-
-DOM queries follow a two-step pattern:
-
-1. Call `DOM.getDocument` to obtain the root node ID.
-2. Call `DOM.querySelector` or `DOM.querySelectorAll` with that node ID and the CSS selector string.
-
-For each matching node, `getElementInfo` calls:
-- `DOM.describeNode` — tag name and attribute list (flat alternating key/value array)
-- `DOM.getBoxModel` — bounding rectangle from the `content` quad
-
-The returned `ElementInfo` carries:
+### ElementInfo
 
 ```go
 type ElementInfo struct {
@@ -123,7 +123,37 @@ type ElementInfo struct {
 }
 ```
 
----
+### BoundingBox
+
+```go
+type BoundingBox struct {
+    X      float64
+    Y      float64
+    Width  float64
+    Height float64
+}
+```
+
+## Navigation
+
+`Navigate(url string) error` calls `Page.navigate` then polls `document.readyState` via `Runtime.evaluate` at 100 ms intervals until the value is `"complete"` or the context deadline is exceeded.
+
+`Reload()`, `GoBack()`, and `GoForward()` follow the same pattern: issue a CDP command then call `waitForLoad`.
+
+`waitForSelector(ctx, selector)` polls `document.querySelector(selector)` at 100 ms intervals until the element exists or the context expires.
+
+## DOM Queries
+
+DOM queries follow a two-step pattern:
+
+1. Call `DOM.getDocument` to obtain the root node ID.
+2. Call `DOM.querySelector` or `DOM.querySelectorAll` with that node ID and the CSS selector string.
+
+For each matching node, `getElementInfo` calls:
+- `DOM.describeNode` -- tag name and attribute list (flat alternating key/value array)
+- `DOM.getBoxModel` -- bounding rectangle from the `content` quad
+
+`QuerySelectorAllAll(selector)` returns an `iter.Seq[*ElementInfo]` iterator for lazy consumption of results.
 
 ## Click and Type
 
@@ -137,8 +167,6 @@ type ElementInfo struct {
 
 `PressKeyAction` handles named keys (Enter, Tab, Escape, Backspace, Delete, arrow keys, Home, End, Page Up, Page Down) by mapping them to their CDP virtual key codes and code strings.
 
----
-
 ## Console Capture
 
 Console capture is enabled in `New()` by subscribing to `Runtime.consoleAPICalled` events.
@@ -148,43 +176,64 @@ Console capture is enabled in `New()` by subscribing to `Runtime.consoleAPICalle
 The `Webview` itself accumulates messages in a slice guarded by `sync.RWMutex`. When the buffer reaches `consoleLimit`, the oldest 100 messages are dropped.
 
 ```go
-msgs := wv.GetConsole()   // returns a copy
+msgs := wv.GetConsole()       // returns a collected slice
 wv.ClearConsole()
+
+// Or iterate lazily
+for msg := range wv.GetConsoleAll() {
+    fmt.Println(msg.Text)
+}
 ```
 
 ### ConsoleWatcher
 
 `ConsoleWatcher` (constructed via `NewConsoleWatcher(wv)`) registers its own handler on the same `Runtime.consoleAPICalled` event. It adds filtering and reactive capabilities:
 
-- `AddFilter(ConsoleFilter)` — filter by message type and/or text pattern
-- `AddHandler(ConsoleHandler)` — callback invoked for each incoming message (outside the write lock)
-- `WaitForMessage(ctx, filter)` — blocks until a matching message arrives
-- `WaitForError(ctx)` — convenience wrapper for `type == "error"`
+- `AddFilter(ConsoleFilter)` -- filter by message type and/or text pattern (substring match)
+- `AddHandler(ConsoleHandler)` -- callback invoked for each incoming message (outside the write lock)
+- `WaitForMessage(ctx, filter)` -- blocks until a matching message arrives
+- `WaitForError(ctx)` -- convenience wrapper for `type == "error"`
 - `Errors()`, `Warnings()`, `HasErrors()`, `ErrorCount()`
+- `FilteredMessages()` / `FilteredMessagesAll()` -- returns messages matching all active filters
 
 ### ExceptionWatcher
 
-`ExceptionWatcher` subscribes to `Runtime.exceptionThrown` events and captures unhandled JavaScript exceptions with full stack traces. It exposes the same reactive pattern as `ConsoleWatcher`: `AddHandler`, `WaitForException`, `HasExceptions`.
+`ExceptionWatcher` subscribes to `Runtime.exceptionThrown` events and captures unhandled JavaScript exceptions with full stack traces:
 
----
+```go
+type ExceptionInfo struct {
+    Text         string
+    LineNumber   int
+    ColumnNumber int
+    URL          string
+    StackTrace   string
+    Timestamp    time.Time
+}
+```
+
+It exposes the same reactive pattern as `ConsoleWatcher`: `AddHandler`, `WaitForException`, `HasExceptions`, `Count`.
+
+### FormatConsoleOutput
+
+The package-level `FormatConsoleOutput(messages)` function formats a slice of `ConsoleMessage` into human-readable lines with timestamp, level prefix (`[ERROR]`, `[WARN]`, `[INFO]`, `[DEBUG]`, `[LOG]`), and message text.
 
 ## Screenshots
 
 `Screenshot()` calls `Page.captureScreenshot` with `format: "png"`. Chrome returns the image as a base64-encoded string in the `data` field of the response. The method decodes this and returns raw PNG bytes.
 
----
-
 ## JavaScript Evaluation
 
 `evaluate(ctx, script)` calls `Runtime.evaluate` with `returnByValue: true`. The result is extracted from `result.result.value`. If `result.exceptionDetails` is present, the error description is returned as a Go error.
 
 `Evaluate(script string) (any, error)` is the public wrapper that applies the default timeout.
 
-`GetURL()` and `GetTitle()` are thin wrappers that evaluate `window.location.href` and `document.title` respectively.
+Convenience wrappers:
 
-`GetHTML(selector string)` evaluates `outerHTML` on the matched element, or `document.documentElement.outerHTML` when the selector is empty.
-
----
+| Method | JavaScript evaluated |
+|--------|---------------------|
+| `GetURL()` | `window.location.href` |
+| `GetTitle()` | `document.title` |
+| `GetHTML(selector)` | `document.querySelector(selector)?.outerHTML` (or `document.documentElement.outerHTML` when selector is empty) |
 
 ## Action System
 
@@ -196,12 +245,36 @@ type Action interface {
 }
 ```
 
-Concrete action types cover: `Click`, `Type`, `Navigate`, `Wait`, `WaitForSelector`, `Scroll`, `ScrollIntoView`, `Focus`, `Blur`, `Clear`, `Select`, `Check`, `Hover`, `DoubleClick`, `RightClick`, `PressKey`, `SetAttribute`, `RemoveAttribute`, `SetValue`.
+### Concrete Action Types
 
-`ActionSequence` provides a fluent builder:
+| Type | Description |
+|------|-------------|
+| `ClickAction` | Click an element by CSS selector |
+| `TypeAction` | Type text into a focused element |
+| `NavigateAction` | Navigate to a URL and wait for load |
+| `WaitAction` | Wait for a fixed duration |
+| `WaitForSelectorAction` | Wait for an element to appear |
+| `ScrollAction` | Scroll to absolute coordinates |
+| `ScrollIntoViewAction` | Scroll an element into view smoothly |
+| `FocusAction` | Focus an element |
+| `BlurAction` | Remove focus from an element |
+| `ClearAction` | Clear an input's value, firing `input` and `change` events |
+| `SelectAction` | Select a value in a `<select>` element |
+| `CheckAction` | Check or uncheck a checkbox |
+| `HoverAction` | Hover over an element |
+| `DoubleClickAction` | Double-click an element |
+| `RightClickAction` | Right-click (context menu) an element |
+| `PressKeyAction` | Press a named key (Enter, Tab, Escape, etc.) |
+| `SetAttributeAction` | Set an HTML attribute on an element |
+| `RemoveAttributeAction` | Remove an HTML attribute from an element |
+| `SetValueAction` | Set an input's value, firing `input` and `change` events |
+
+### ActionSequence
+
+`ActionSequence` provides a fluent builder. Actions are executed sequentially; the first failure halts the sequence and returns the action index with the error.
 
 ```go
-err := NewActionSequence().
+err := webview.NewActionSequence().
     Navigate("https://example.com").
     WaitForSelector("#login-form").
     Type("#email", "user@example.com").
@@ -210,23 +283,24 @@ err := NewActionSequence().
     Execute(ctx, wv)
 ```
 
-`Execute` runs actions sequentially and returns the index and error of the first failure.
-
 ### File Upload and Drag-and-Drop
 
-`UploadFile(selector, filePaths)` uses `DOM.setFileInputFiles` on the node ID of the resolved file input element.
+These are methods on `Webview` rather than action types:
 
-`DragAndDrop(sourceSelector, targetSelector)` dispatches `mousePressed`, `mouseMoved`, and `mouseReleased` events between the centre points of the two elements.
-
----
+- `UploadFile(selector, filePaths)` -- uses `DOM.setFileInputFiles` on the resolved file input node
+- `DragAndDrop(sourceSelector, targetSelector)` -- dispatches `mousePressed`, `mouseMoved`, and `mouseReleased` events between the centre points of two elements
 
 ## Angular Helpers
 
-`AngularHelper` (constructed via `NewAngularHelper(wv)`) provides SPA-specific utilities. All methods accept the `AngularHelper.timeout` deadline (default 30 s).
+`AngularHelper` (constructed via `NewAngularHelper(wv)`) provides SPA-specific utilities for Angular 2+ applications. All methods use the helper's configurable timeout (default 30 seconds).
 
 ### Application Detection
 
-`isAngularApp` checks for Angular 2+ via `window.getAllAngularRootElements`, the `[ng-version]` attribute, or `window.ng.probe`. It also checks for AngularJS 1.x via `window.angular.element`.
+`isAngularApp` checks for Angular by probing:
+- `window.getAllAngularRootElements` (Angular 2+)
+- The `[ng-version]` attribute on DOM elements
+- `window.ng.probe` (Angular debug utilities)
+- `window.angular.element` (AngularJS 1.x)
 
 ### Zone.js Stability
 
@@ -234,44 +308,45 @@ err := NewActionSequence().
 
 ### Router Integration
 
-`NavigateByRouter(path)` obtains the `Router` service from the Angular injector and calls `router.navigateByUrl(path)`, then waits for Zone.js stability.
-
-`GetRouterState()` returns an `AngularRouterState` with the current URL, fragment, route params, and query params.
+- `NavigateByRouter(path)` -- obtains the `Router` service from the Angular injector, calls `router.navigateByUrl(path)`, then waits for Zone.js stability
+- `GetRouterState()` -- returns an `AngularRouterState` with the current URL, fragment, route params, and query params
 
 ### Component Introspection
 
-`GetComponentProperty(selector, property)` and `SetComponentProperty(selector, property, value)` access component instances via `window.ng.probe(element).componentInstance`. After setting a property, `ApplicationRef.tick()` is called to trigger change detection.
+These methods require the Angular application to be running in debug mode (`window.ng.probe` must be available):
 
-`CallComponentMethod(selector, method, args...)` invokes a method on the component instance and triggers change detection.
+- `GetComponentProperty(selector, property)` -- reads a property from a component instance
+- `SetComponentProperty(selector, property, value)` -- writes a property and triggers `ApplicationRef.tick()`
+- `CallComponentMethod(selector, method, args...)` -- invokes a method and triggers change detection
+- `GetService(name)` -- retrieves a named service from the root injector, returned as a JSON-serialisable value
 
-`GetService(name)` retrieves a named service from the root injector and returns a JSON-serialisable representation.
+### ngModel Access
 
-### ngModel
+- `GetNgModel(selector)` -- reads the current value of an ngModel-bound input
+- `SetNgModel(selector, value)` -- writes the value, fires `input` and `change` events, and triggers `ApplicationRef.tick()`
 
-`GetNgModel(selector)` reads the current value of an ngModel-bound input. `SetNgModel(selector, value)` writes the value, fires `input` and `change` events, and triggers `ApplicationRef.tick()`.
+### Other Helpers
 
----
+- `TriggerChangeDetection()` -- manually triggers `ApplicationRef.tick()` across all root elements
+- `WaitForComponent(selector)` -- polls until a component instance exists on the matched element
+- `DispatchEvent(selector, eventName, detail)` -- dispatches a `CustomEvent` on an element
 
 ## Multi-Tab Support
 
 `CDPClient.NewTab(url)` calls `GET {debugURL}/json/new?{url}` and returns a new `CDPClient` connected to the WebSocket of the newly created tab. Each tab has its own independent read loop and event handler registry, so console events and other notifications are tab-scoped.
 
-`CDPClient.CloseTab()` calls `Browser.close` on the tab's CDP session.
+`ListTargets(debugURL)` and `ListTargetsAll(debugURL)` are package-level utilities that query the HTTP endpoint without requiring an active WebSocket connection. `ListTargetsAll` returns an `iter.Seq[targetInfo]` iterator.
 
-`ListTargets(debugURL)` and `GetVersion(debugURL)` are package-level utilities that query the HTTP endpoint without requiring an active WebSocket connection.
-
----
+`GetVersion(debugURL)` returns Chrome version information as a string map.
 
 ## Emulation
 
-`SetViewport(width, height int)` calls `Emulation.setDeviceMetricsOverride` with `deviceScaleFactor: 1` and `mobile: false`.
-
-`SetUserAgent(ua string)` calls `Emulation.setUserAgentOverride`.
-
----
+- `SetViewport(width, height int)` -- calls `Emulation.setDeviceMetricsOverride` with `deviceScaleFactor: 1` and `mobile: false`
+- `SetUserAgent(ua string)` -- calls `Emulation.setUserAgentOverride`
 
 ## Thread Safety
 
-- `CDPClient` uses `sync.RWMutex` for WebSocket writes and `sync.Mutex` for the pending-response map. Event handler registration uses a separate `sync.RWMutex`.
-- `Webview` uses `sync.RWMutex` for its console log slice.
-- `ConsoleWatcher` and `ExceptionWatcher` use `sync.RWMutex` for their message and handler slices. Handlers are copied before being called so they execute outside the write lock.
+- **CDPClient** uses `sync.RWMutex` for WebSocket writes and `sync.Mutex` for the pending-response map. Event handler registration uses a separate `sync.RWMutex`.
+- **Webview** uses `sync.RWMutex` for its console log slice.
+- **ConsoleWatcher** and **ExceptionWatcher** use `sync.RWMutex` for their message and handler slices. Handlers are copied before being called so they execute outside the write lock.
+- Event handlers registered via `OnEvent` are dispatched in separate goroutines so they cannot block the WebSocket read loop.

docs/convention-drift-audit.md

@@ -0,0 +1,42 @@
+# Convention Drift Audit
+
+Date: 2026-03-23
+
+Scope notes:
+- `CLAUDE.md` reviewed.
+- `CODEX.md` was not present anywhere under `/workspace`, so this audit is based on `CLAUDE.md` and the checked-in repository docs.
+- `go test ./...` passes.
+- `go test -coverprofile=webview.cover ./...` reports `16.1%` statement coverage.
+- No source fixes were applied as part of this audit.
+
+## `stdlib` -> `core.*`
+
+- `docs/development.md:120` still tells contributors to wrap errors with `fmt.Errorf("context: %w", err)` so callers can use `errors.Is` and `errors.As`; `CLAUDE.md` now requires `coreerr.E("Scope.Method", "description", err)`. This is documentation drift rather than code drift.
+
+## UK English
+
+- `README.md:2` uses `License` in the badge alt text and badge label.
+- `CONTRIBUTING.md:34` uses the US heading `License` instead of `Licence`.
+- `docs/development.md:138` uses `licenced`; that is inconsistent with the repo's other licence/licensed wording.
+- `webview.go:705` says `center coordinates` in a comment.
+- `webview.go:718` says `center point` in a comment.
+- `actions.go:511` says `center points` in a comment.
+
+## Missing tests
+
+- `actions.go:22`, `actions.go:33`, `actions.go:43`, `actions.go:74`, `actions.go:85`, `actions.go:97`, `actions.go:109`, `actions.go:121`, `actions.go:133`, `actions.go:153`, `actions.go:172`, `actions.go:189`, `actions.go:216`, `actions.go:263`, `actions.go:307`, `actions.go:378`, `actions.go:391`, `actions.go:404`, `actions.go:461`, `actions.go:471`, `actions.go:490` have no behavioural coverage. Existing action tests in `webview_test.go` only check field assignment and builder length, not execution paths.
+- `angular.go:19`, `angular.go:27`, `angular.go:33`, `angular.go:41`, `angular.go:56`, `angular.go:93`, `angular.go:183`, `angular.go:214`, `angular.go:251`, `angular.go:331`, `angular.go:353`, `angular.go:384`, `angular.go:425`, `angular.go:453`, `angular.go:480`, `angular.go:517`, `angular.go:543`, `angular.go:570` are entirely uncovered. The Angular helper layer has no `_Good`, `_Bad`, or `_Ugly` behavioural tests.
+- `cdp.go:78` is only lightly exercised by the invalid-debug-URL path; there is no success-path coverage for target discovery, tab creation, or WebSocket connection setup.
+- `cdp.go:156`, `cdp.go:163`, `cdp.go:205`, `cdp.go:212`, `cdp.go:255`, `cdp.go:267`, `cdp.go:279`, `cdp.go:284`, `cdp.go:289`, `cdp.go:340`, `cdp.go:351`, `cdp.go:372`, `cdp.go:387` have no direct behavioural coverage for transport lifecycle, event dispatch, tab management, target enumeration, or version probing.
+- `console.go:33`, `console.go:72`, `console.go:79`, `console.go:84`, `console.go:168`, `console.go:207`, `console.go:246`, `console.go:371`, `console.go:427`, `console.go:434`, `console.go:469` have no direct tests. The concurrency-sensitive watcher subscription, wait APIs, and event parsing paths are currently unverified.
+- `webview.go:81` and `webview.go:110` are only partially covered; there is no success-path test for `WithDebugURL` plus `New` initialisation, including `Runtime.enable`, `Page.enable`, and `DOM.enable`.
+- `webview.go:143`, `webview.go:152`, `webview.go:168`, `webview.go:176`, `webview.go:184`, `webview.go:192`, `webview.go:200`, `webview.go:219`, `webview.go:224`, `webview.go:238`, `webview.go:245`, `webview.go:272`, `webview.go:280`, `webview.go:288`, `webview.go:306`, `webview.go:324`, `webview.go:349`, `webview.go:363`, `webview.go:374`, `webview.go:387`, `webview.go:398`, `webview.go:422`, `webview.go:453`, `webview.go:495`, `webview.go:517`, `webview.go:541`, `webview.go:569`, `webview.go:604`, `webview.go:648`, `webview.go:704`, `webview.go:740` have no direct behavioural coverage across the main browser API, DOM lookup helpers, CDP evaluation path, and console capture path.
+
+## SPDX headers
+
+- `actions.go:1` is missing the required `// SPDX-License-Identifier: EUPL-1.2` header.
+- `angular.go:1` is missing the required `// SPDX-License-Identifier: EUPL-1.2` header.
+- `cdp.go:1` is missing the required `// SPDX-License-Identifier: EUPL-1.2` header.
+- `console.go:1` is missing the required `// SPDX-License-Identifier: EUPL-1.2` header.
+- `webview.go:1` is missing the required `// SPDX-License-Identifier: EUPL-1.2` header.
+- `webview_test.go:1` is missing the required `// SPDX-License-Identifier: EUPL-1.2` header.

docs/development.md

@@ -1,10 +1,15 @@
+---
+title: Development Guide
+description: How to build, test, and contribute to go-webview -- prerequisites, test patterns, coding standards, and extension guides.
+---
+
 # Development Guide
 
 ## Prerequisites
 
 ### Go
 
-Go 1.25 or later is required. The module path is `forge.lthn.ai/core/go-webview`.
+Go 1.26 or later is required. The module path is `dappco.re/go/core/webview`.
 
 ### Chrome or Chromium
 
@@ -38,8 +43,6 @@ The only runtime dependency is `github.com/gorilla/websocket v1.5.3`, declared i
 go mod download
 ```
 
----
-
 ## Build and Test
 
 ### Running Tests
@@ -48,7 +51,7 @@ go mod download
 go test ./...
 ```
 
-Tests must pass before committing. There are currently no build tags that gate tests behind a Chrome connection; the integration tests in `webview_test.go` that require a live browser (`TestNew_Bad_InvalidDebugURL`) will fail gracefully because they assert that the error is non-nil when connecting to an unavailable port.
+Tests must pass before committing. The integration tests in `webview_test.go` that reference a live browser (`TestNew_Bad_InvalidDebugURL`) are designed to fail gracefully -- they assert that the error is non-nil when connecting to an unavailable port.
 
 ```bash
 # Run a specific test
@@ -58,17 +61,24 @@ go test -v -run TestActionSequence_Good ./...
 go test -v ./...
 ```
 
+### Vetting and Formatting
+
+```bash
+gofmt -w .
+go vet ./...
+```
+
 ### Test Naming Convention
 
 Tests follow the `_Good`, `_Bad`, `_Ugly` suffix pattern, consistent with the broader Core Go ecosystem:
 
-- `_Good` — happy path, verifies correct behaviour under valid input.
-- `_Bad` — expected error conditions, verifies that errors are returned and have the correct shape.
-- `_Ugly` — panic/edge cases, unexpected or degenerate inputs.
+- `_Good` -- happy path, verifies correct behaviour under valid input.
+- `_Bad` -- expected error conditions, verifies that errors are returned and have the correct shape.
+- `_Ugly` -- panic/edge cases, unexpected or degenerate inputs.
 
 All test functions use the standard `testing.T` interface; the project does not use a test framework.
 
-### CI Headless Tests
+### Headless CI Tests
 
 To add tests that exercise the full CDP stack in CI:
 
@@ -76,21 +86,19 @@ To add tests that exercise the full CDP stack in CI:
 2. Serve test fixtures using `net/http/httptest` so tests do not depend on external URLs.
 3. Use `WithTimeout` to set conservative deadlines appropriate for the CI environment.
 
----
-
 ## Code Organisation
 
 New source files belong in the root package (`package webview`). The package is intentionally a single flat package; do not create sub-packages.
 
 Keep separation between layers:
 
-- **CDP transport** — `cdp.go`. Do not put browser-level logic here.
-- **High-level API** — `webview.go`. Methods here should be safe to call from application code without CDP knowledge.
-- **Action types** — `actions.go`. Add new action types here; keep each action focused on a single interaction.
-- **Diagnostics** — `console.go`. Console and exception capture live here.
-- **SPA helpers** — `angular.go`. Framework-specific helpers belong here or in a new file named after the framework (e.g. `react.go`, `vue.go`).
-
----
+| Layer | File | Guidance |
+|-------|------|----------|
+| CDP transport | `cdp.go` | Do not put browser-level logic here. |
+| High-level API | `webview.go` | Methods here should be safe to call from application code without CDP knowledge. |
+| Action types | `actions.go` | Add new action types here; keep each action focused on a single interaction. |
+| Diagnostics | `console.go` | Console and exception capture live here. |
+| SPA helpers | `angular.go` | Framework-specific helpers belong here or in a new file named after the framework (e.g. `react.go`, `vue.go`). |
 
 ## Coding Standards
 
@@ -129,8 +137,6 @@ Every Go source file must begin with:
 
 The project is licenced under the European Union Public Licence 1.2 (EUPL-1.2).
 
----
-
 ## Commit Guidelines
 
 Use conventional commits:
@@ -160,8 +166,6 @@ WaitForException API consistent with ConsoleWatcher.
 Co-Authored-By: Virgil <virgil@lethean.io>
 ```
 
----
-
 ## Adding a New Action Type
 
 1. Define a struct in `actions.go` with exported fields for the action's parameters.
@@ -188,8 +192,6 @@ func (s *ActionSequence) Submit(selector string) *ActionSequence {
 }
 ```
 
----
-
 ## Adding a New Angular Helper
 
 Add methods to `AngularHelper` in `angular.go`. Follow the established pattern:
@@ -200,7 +202,14 @@ Add methods to `AngularHelper` in `angular.go`. Follow the established pattern:
 4. After state-modifying operations, call `TriggerChangeDetection()` or inline `appRef.tick()`.
 5. For polling-based waits, use a `time.NewTicker` at 100 ms and select over `ctx.Done()`.
 
----
+## Adding a New SPA Framework Helper
+
+To add support for a different single-page application framework (e.g. React, Vue):
+
+1. Create a new file named after the framework (e.g. `react.go`).
+2. Define a helper struct that holds a `*Webview` reference and a configurable timeout.
+3. Use `evaluate()` to inject JavaScript that probes framework-specific globals and APIs.
+4. Follow the same `context.WithTimeout` + polling pattern established in `angular.go`.
 
 ## Forge Push
 

docs/history.md

@@ -2,7 +2,7 @@
 
 ## Origin
 
-go-webview was extracted from the `pkg/webview/` directory of `forge.lthn.ai/core/go` on 19 February 2026 by Virgil. The extraction made the package independently importable and gave it its own module path, dependency management, and commit history.
+go-webview was extracted from the `pkg/webview/` directory of `dappco.re/go/core` on 19 February 2026 by Virgil. The extraction made the package independently importable and gave it its own module path, dependency management, and commit history.
 
 ---
 
@@ -12,7 +12,7 @@ go-webview was extracted from the `pkg/webview/` directory of `forge.lthn.ai/cor
 
 Commit `45f119b9ac0e0ebe34f5c8387a070a5b8bd2de6b` — 2026-02-19
 
-Initial extraction. All source files were moved from `go` `pkg/webview/` into the root of this repository. The module was renamed from the internal path to `forge.lthn.ai/core/go-webview`.
+Initial extraction. All source files were moved from `go` `pkg/webview/` into the root of this repository. The module was renamed from the internal path to `dappco.re/go/core/webview`.
 
 Files established at extraction:
 

docs/index.md

@@ -0,0 +1,143 @@
+---
+title: go-webview
+description: Chrome DevTools Protocol client for browser automation, testing, and scraping in Go.
+---
+
+# go-webview
+
+`go-webview` is a Go package that provides browser automation via the Chrome DevTools Protocol (CDP). It connects to an externally managed Chrome or Chromium instance running with `--remote-debugging-port=9222` and exposes a high-level API for navigation, DOM queries, input simulation, screenshot capture, console monitoring, and JavaScript evaluation.
+
+The package does not launch Chrome itself. The caller is responsible for starting the browser process before constructing a `Webview`.
+
+**Module path:** `dappco.re/go/core/webview`
+**Licence:** EUPL-1.2
+**Go version:** 1.26+
+**Dependencies:** `github.com/gorilla/websocket v1.5.3`
+
+## Quick Start
+
+Start Chrome with the remote debugging port enabled:
+
+```bash
+# macOS
+/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome \
+    --remote-debugging-port=9222
+
+# Linux
+google-chrome --remote-debugging-port=9222
+
+# Headless (suitable for CI)
+google-chrome --headless=new --remote-debugging-port=9222 --no-sandbox --disable-gpu
+```
+
+Then use the package in Go:
+
+```go
+import "dappco.re/go/core/webview"
+
+// Connect to Chrome
+wv, err := webview.New(webview.WithDebugURL("http://localhost:9222"))
+if err != nil {
+    log.Fatal(err)
+}
+defer wv.Close()
+
+// Navigate and interact
+if err := wv.Navigate("https://example.com"); err != nil {
+    log.Fatal(err)
+}
+if err := wv.Click("#submit-button"); err != nil {
+    log.Fatal(err)
+}
+```
+
+### Fluent Action Sequences
+
+Chain multiple browser actions together with `ActionSequence`:
+
+```go
+err := webview.NewActionSequence().
+    Navigate("https://example.com").
+    WaitForSelector("#login-form").
+    Type("#email", "user@example.com").
+    Type("#password", "secret").
+    Click("#submit").
+    Execute(ctx, wv)
+```
+
+### Console Monitoring
+
+Capture and filter browser console output:
+
+```go
+cw := webview.NewConsoleWatcher(wv)
+cw.AddFilter(webview.ConsoleFilter{Type: "error"})
+
+// ... perform browser actions ...
+
+if cw.HasErrors() {
+    for _, msg := range cw.Errors() {
+        log.Printf("JS error: %s at %s:%d", msg.Text, msg.URL, msg.Line)
+    }
+}
+```
+
+### Screenshots
+
+Capture the current page as PNG:
+
+```go
+png, err := wv.Screenshot()
+if err != nil {
+    log.Fatal(err)
+}
+os.WriteFile("screenshot.png", png, 0644)
+```
+
+### Angular Applications
+
+First-class support for Angular single-page applications:
+
+```go
+ah := webview.NewAngularHelper(wv)
+
+// Wait for Angular to stabilise
+if err := ah.WaitForAngular(); err != nil {
+    log.Fatal(err)
+}
+
+// Navigate using Angular Router
+if err := ah.NavigateByRouter("/dashboard"); err != nil {
+    log.Fatal(err)
+}
+
+// Inspect component state (debug mode only)
+value, err := ah.GetComponentProperty("app-widget", "title")
+```
+
+## Package Layout
+
+| File | Responsibility |
+|------|----------------|
+| `webview.go` | `Webview` struct, public API (navigate, click, type, screenshot, JS evaluation, DOM queries) |
+| `cdp.go` | `CDPClient` -- WebSocket transport, CDP message framing, event dispatch, tab management |
+| `actions.go` | `Action` interface, 19 concrete action types, `ActionSequence` fluent builder |
+| `console.go` | `ConsoleWatcher`, `ExceptionWatcher`, console log formatting |
+| `angular.go` | `AngularHelper` -- Zone.js stability, router navigation, component introspection, ngModel |
+| `webview_test.go` | Unit tests for structs, options, and action building |
+
+## Configuration Options
+
+| Option | Default | Description |
+|--------|---------|-------------|
+| `WithDebugURL(url)` | *(required)* | Chrome DevTools HTTP debug endpoint, e.g. `http://localhost:9222` |
+| `WithTimeout(d)` | 30 seconds | Default timeout for all browser operations |
+| `WithConsoleLimit(n)` | 1000 | Maximum number of console messages retained in memory |
+
+## Further Documentation
+
+- [API Contract](api-contract.md) -- exported type, function, and method inventory with signatures and test coverage notes
+- [Architecture](architecture.md) -- internals, data flow, CDP protocol, type reference
+- [Development Guide](development.md) -- build, test, contribute, coding standards
+- [Project History](history.md) -- extraction origin, completed phases, known limitations
+- [Security Attack Vector Mapping](security-attack-vector-mapping.md) -- external input entry points, current validation, and attack-surface notes

docs/security-attack-vector-mapping.md

@@ -0,0 +1,65 @@
+# Security Attack Vector Mapping
+
+Date: 2026-03-23
+
+Notes:
+- `CODEX.md` was not present in this repository when this mapping was prepared, so repo-specific conventions were taken from `CLAUDE.md`.
+- Thin wrappers are grouped with the underlying sink when they share the same trust boundary and behaviour. Examples: `ActionSequence.Navigate` is grouped with `NavigateAction.Execute` and `Webview.Navigate`.
+- This is a mapping document only. No mitigations or code changes are proposed here.
+
+## Caller-Controlled Inputs
+
+| Function | File:line | Input source | What it flows into | Current validation | Potential attack vector |
+|---|---|---|---|---|---|
+| `WithDebugURL`, `NewCDPClient`, `ListTargets`, `ListTargetsAll`, `GetVersion` | `webview.go:81`<br>`cdp.go:78`<br>`cdp.go:351`<br>`cdp.go:372`<br>`cdp.go:387` | Caller-supplied Chrome debug URL | `http.Get(debugURL + "/json")`, `http.Get(debugURL + "/json/version")`, `json.Unmarshal`, and, in `NewCDPClient`, `websocket.DefaultDialer.Dial` to the returned `webSocketDebuggerUrl` | No scheme, host, auth, status-code, or body-size validation; JSON shape trusted after `json.Unmarshal` | SSRF against arbitrary internal hosts; unauthenticated trust in a hostile CDP endpoint; malicious `/json` can steer the code into a WS connection to an attacker host; large responses can cause memory pressure |
+| `CDPClient.NewTab` | `cdp.go:289` | Caller-supplied URL for the new tab; remote `/json/new` response body | Raw string concatenation into `debugURL + "/json/new?" + url`, then `http.Get`, `json.Unmarshal`, and `websocket.DefaultDialer.Dial` to the returned WS URL | No URL escaping; no scheme or destination checks; no status-code or body-size validation | Query manipulation against the debug endpoint; opening attacker-chosen pages in the browser; SSRF through the debug service; hostile response can redirect the WS dial |
+| `CDPClient.Call`, `CDPClient.Send` | `cdp.go:163`<br>`cdp.go:267` | Caller-supplied CDP method names and params | JSON serialisation to the live DevTools WebSocket | No allow-list or schema validation beyond JSON encoding | Arbitrary CDP command execution, including powerful browser control primitives; blind fire-and-forget misuse via `Send`; broader blast radius if an untrusted component can reach this API |
+| `CDPClient.OnEvent` | `cdp.go:205` | Caller-supplied event names and callbacks | Stored in `handlers`, later invoked by `dispatchEvent` for browser-originated CDP events | No validation or deduplication | Unbounded handler registration; browser event floods can amplify into caller callback fan-out and goroutine pressure |
+| `Webview.Navigate`, `NavigateAction.Execute`, `ActionSequence.Navigate` | `webview.go:152`<br>`actions.go:43`<br>`actions.go:446` | Caller-supplied navigation URL or action field | CDP `Page.navigate`, then `waitForLoad` polling via `Runtime.evaluate("document.readyState")` | No scheme, host, or destination validation | Browser-mediated SSRF to internal services; navigation to sensitive schemes such as `file:`, `data:`, `javascript:`, or others if Chrome permits; automation redirection into attacker-controlled flows |
+| `Webview.Click`, `ClickAction.Execute`, `ActionSequence.Click` | `webview.go:168`<br>`webview.go:704`<br>`actions.go:22`<br>`actions.go:436` | Caller-supplied CSS selector or action field | `DOM.querySelector`; either CDP mouse events or JS fallback `document.querySelector(%q)?.click()` | Only existence and bounding-box checks; JS fallback uses `%q` for selector quoting | Expensive selector abuse against large DOMs; arbitrary interaction with attacker-chosen elements; destructive clicks inside a privileged browser session |
+| `Webview.Type`, `TypeAction.Execute`, `ActionSequence.Type` | `webview.go:176`<br>`webview.go:740`<br>`actions.go:33`<br>`actions.go:441` | Caller-supplied selector and text | JS focus script, then `Input.dispatchKeyEvent` for each rune | Selector is JS-quoted with `%q`; text is unbounded | Arbitrary input injection into forms and widgets; credential stuffing into the current page; large payloads can generate high event volume |
+| `Webview.QuerySelector` | `webview.go:184`<br>`webview.go:569` | Caller-supplied selector | `DOM.getDocument`, `DOM.querySelector`, `DOM.describeNode`, `DOM.getBoxModel`, then `ElementInfo` returned | No selector validation beyond CDP/browser parsing; result fields only type-asserted | DOM metadata exfiltration from an untrusted page; attacker-controlled attribute values returned to the caller; selector complexity abuse |
+| `Webview.QuerySelectorAll`, `Webview.QuerySelectorAllAll` | `webview.go:192`<br>`webview.go:200`<br>`webview.go:604` | Caller-supplied selector | `DOM.querySelectorAll`, then `getElementInfo` per returned node | No selector validation beyond CDP/browser parsing; no cap on result count | Large node sets can amplify CPU and memory use; DOM data exfiltration; selector complexity abuse |
+| `Webview.WaitForSelector`, `WaitForSelectorAction.Execute`, `ActionSequence.WaitForSelector` | `webview.go:280`<br>`webview.go:517`<br>`actions.go:74`<br>`actions.go:456` | Caller-supplied selector | Repeated `Runtime.evaluate("!!document.querySelector(%q)")` until timeout | Selector is JS-quoted with `%q`; no complexity or rate limits beyond the 100 ms ticker | Polling on hostile/large DOMs can create steady CPU load; attacker controls when the wait resolves |
+| `Webview.Evaluate` | `webview.go:272`<br>`webview.go:541` | Caller-supplied JavaScript source | CDP `Runtime.evaluate` with `returnByValue: true`, result returned to caller | No validation; this surface is intentionally arbitrary | Direct arbitrary JS execution in the page; DOM/session data exfiltration; page mutation; leverage of any privileged browser APIs exposed to the page context |
+| `Webview.GetHTML` | `webview.go:324` | Optional caller-supplied selector | Fixed or selector-based JS passed to `Runtime.evaluate`, HTML returned | Selector is JS-quoted with `%q`; no output size limit | Full-document or targeted DOM exfiltration; large HTML payloads can cause memory pressure; selector complexity abuse |
+| `Webview.SetViewport` | `webview.go:349` | Caller-supplied width and height | CDP `Emulation.setDeviceMetricsOverride` | No range checks | Extreme dimensions can drive browser resource use or renderer instability |
+| `Webview.SetUserAgent` | `webview.go:363` | Caller-supplied User-Agent string | CDP `Emulation.setUserAgentOverride` | No allow-list or content filtering in package code | Header spoofing, app feature-gating bypass, and downstream log pollution if Chrome accepts unusual characters |
+| `Webview.UploadFile` | `actions.go:471` | Caller-supplied selector and local file paths | `DOM.setFileInputFiles` | Selector must resolve; file paths are not normalised, existence-checked, or restricted | Sensitive local file selection followed by browser-side upload or exfiltration if the page submits the form |
+| `Webview.DragAndDrop` | `actions.go:490` | Caller-supplied source and target selectors | `querySelector` for both ends, then `Input.dispatchMouseEvent` sequence | Existence and bounding-box checks only | Arbitrary drag/drop interactions in a privileged session; selector complexity abuse |
+| `ScrollAction.Execute` | `actions.go:85` | Caller-populated X/Y values | Raw JS `window.scrollTo(%d, %d)` via `Webview.evaluate` | Numeric formatting only | Large values can produce unexpected page behaviour; lower-risk than the arbitrary-script surface but still direct page control |
+| `ScrollIntoViewAction.Execute`, `FocusAction.Execute`, `BlurAction.Execute`, `ClearAction.Execute`, `SelectAction.Execute`, `CheckAction.Execute`, `SetAttributeAction.Execute`, `RemoveAttributeAction.Execute`, `SetValueAction.Execute` | `actions.go:97`<br>`actions.go:109`<br>`actions.go:121`<br>`actions.go:133`<br>`actions.go:153`<br>`actions.go:172`<br>`actions.go:378`<br>`actions.go:391`<br>`actions.go:404` | Caller-populated selector, value, attribute, or checked-state fields | Constructed JS passed to `Webview.evaluate`; several rows also dispatch `input`/`change` events | String inputs are JS-quoted with `%q`; no semantic allow-list or size checks | Arbitrary DOM mutation and synthetic event dispatch; selector complexity abuse; low direct string-injection risk because `%q` quoting is used |
+| `HoverAction.Execute`, `DoubleClickAction.Execute`, `RightClickAction.Execute` | `actions.go:189`<br>`actions.go:216`<br>`actions.go:263` | Caller-populated selectors | `querySelector` plus CDP mouse events, with JS fallbacks for double/right click | Existence and bounding-box checks; fallback selectors are JS-quoted with `%q` | Arbitrary pointer interaction, including double-click and context-menu behaviour inside a privileged session; selector complexity abuse |
+| `PressKeyAction.Execute` | `actions.go:307` | Caller-populated key name or text | `Input.dispatchKeyEvent`; unknown keys are sent as raw `"text"` | Small allow-list for common keys; all other input is passed through | Synthetic keystroke injection, control-character delivery, and high-volume key event generation |
+| `AngularHelper.NavigateByRouter` | `angular.go:214` | Caller-supplied Angular router path | JS `router.navigateByUrl(%q)` followed by Zone stability wait | Path is JS-quoted with `%q`; no route allow-list | Route manipulation inside a privileged SPA session; app-specific workflow or authorisation bypass if an untrusted caller controls the path |
+| `AngularHelper.GetComponentProperty` | `angular.go:331` | Caller-supplied selector and property name | JS querySelector, `window.ng.probe(element).componentInstance`, then `component[%q]` returned | Selector in `querySelector` and property name are quoted, but selector is also interpolated raw into an error string with `%s` | Arbitrary component state read; JS injection if a crafted selector forces the error path and breaks out of the raw error string |
+| `AngularHelper.SetComponentProperty` | `angular.go:353` | Caller-supplied selector, property name, and value | JS querySelector, `component[%q] = %v`, then `ApplicationRef.tick()` | Property name is quoted; selector also appears raw in an error string; `formatJSValue` only safely quotes strings, bools, and `nil`, and uses raw `%v` otherwise | Arbitrary component state mutation; JS injection via the raw selector error path or via crafted non-primitive values rendered with raw `%v` |
+| `AngularHelper.CallComponentMethod` | `angular.go:384` | Caller-supplied selector, method name, and args | JS querySelector, `component[%q](%s)`, then `ApplicationRef.tick()` | Method name is quoted at call time but also appears raw in an error string; args use `formatJSValue` | Arbitrary component method invocation; JS injection via selector/method-name error paths or crafted args rendered with raw `%v` |
+| `AngularHelper.GetService` | `angular.go:453` | Caller-supplied Angular DI token name | JS `injector.get(%q)` followed by `JSON.stringify/parse`, returned to caller | Service name is JS-quoted; no size or content limits on serialised output | Exfiltration of DI service state from debug-enabled Angular apps; large services can cause serialisation or memory pressure |
+| `AngularHelper.WaitForComponent` | `angular.go:480` | Caller-supplied selector | Repeated JS querySelector plus `window.ng.probe` until timeout | Selector is JS-quoted with `%q` | Polling on hostile DOMs can create steady CPU load; attacker controls when the wait resolves |
+| `AngularHelper.DispatchEvent` | `angular.go:517` | Caller-supplied selector, event name, and detail payload | JS `new CustomEvent(%q, { bubbles: true, detail: %s })`, then `dispatchEvent` | Event name is quoted; selector also appears raw in an error string; `detail` uses `formatJSValue` | Synthetic event injection into Angular app logic; JS injection via the raw selector error path or crafted detail rendered with raw `%v` |
+| `AngularHelper.GetNgModel` | `angular.go:543` | Caller-supplied selector | JS querySelector, optional Angular debug probe, value/text returned to caller | Selector is JS-quoted with `%q` | Exfiltration of form or model values from the current page |
+| `AngularHelper.SetNgModel` | `angular.go:570` | Caller-supplied selector and value | JS `element.value = %v`, `input`/`change` events, and `ApplicationRef.tick()` | Selector also appears raw in an error string; value uses `formatJSValue` | Arbitrary model mutation; business-logic and event injection; JS injection via raw selector error path or crafted value rendered with raw `%v` |
+| `ConsoleWatcher.WaitForMessage` | `console.go:168` | Caller-supplied filter pattern plus browser-originated console text | Substring scans over stored and future console messages | No pattern-length cap or escaping | Large attacker-controlled log lines combined with long caller-supplied patterns can amplify CPU use; hostile pages can control when the wait resolves |
+| `FormatConsoleOutput` | `console.go:524` | Caller- or browser-supplied `ConsoleMessage` fields | Raw `fmt.Sprintf` into output lines | No sanitisation of text, URL, or prefix content | Log forging and terminal escape propagation if the formatted output is printed or persisted verbatim |
+
+## Browser- and CDP-Originated Inputs
+
+| Function | File:line | Input source | What it flows into | Current validation | Potential attack vector |
+|---|---|---|---|---|---|
+| `CDPClient.readLoop` | `cdp.go:212` | Raw WebSocket frames from the connected CDP peer | `json.Unmarshal` into `cdpResponse` or `cdpEvent`, then pending response channels or `dispatchEvent` | No explicit frame-size limit, schema validation, origin check, or auth check; malformed frames are mostly ignored | Memory pressure from large frames; silent desynchronisation; spoofed responses/events from a hostile endpoint; event-flood delivery into higher layers |
+| `CDPClient.dispatchEvent` | `cdp.go:255` | CDP event method and params forwarded from `readLoop` | One goroutine per registered handler | Clones the handler slice but does not rate-limit or bound concurrency | Goroutine exhaustion and scheduler pressure under high-volume event streams |
+| `Webview.Screenshot` | `webview.go:245` | Browser-supplied base64 screenshot payload | Base64 decode into a byte slice returned to caller | Type assertion and base64 decode only; no size cap | Large screenshot payloads can cause memory pressure or decode-time DoS |
+| `Webview.handleConsoleEvent` | `webview.go:453` | `Runtime.consoleAPICalled` event params from the page via CDP | Builds `ConsoleMessage` and appends it to the Webview ring buffer | Best-effort type assertions only; no sanitisation of text, URL, or stack data | Log forging, terminal escape propagation, and bounded memory pressure up to `consoleLimit` |
+| `NewConsoleWatcher`, `ConsoleWatcher.handleConsoleEvent` | `console.go:33`<br>`console.go:246` | `Runtime.consoleAPICalled` event params from the page via CDP | Builds `ConsoleMessage`, stores it in the watcher buffer, then notifies registered handlers | Best-effort type assertions only; bounded by `limit`; no sanitisation | Caller handler fan-out on attacker-controlled log data; bounded memory pressure; log forging |
+| `NewExceptionWatcher`, `ExceptionWatcher.handleException` | `console.go:371`<br>`console.go:468` | `Runtime.exceptionThrown` event params from the page via CDP | Extracts exception text and stack trace, appends to `ew.exceptions`, then calls registered handlers | Best-effort type assertions only; no sanitisation; no retention limit | Unbounded memory growth under exception spam; attacker-controlled stack traces and text reaching caller sinks; handler fan-out DoS |
+| `ExceptionWatcher.WaitForException` | `console.go:434` | Stored and future browser-originated exception data | Returns the latest `ExceptionInfo` to the caller | No validation beyond prior parsing | Attacker controls exception timing and payload content that may be logged or acted on by the caller |
+| `Webview.GetURL`, `Webview.GetTitle` | `webview.go:288`<br>`webview.go:306` | Page-controlled `window.location.href` and `document.title` values | Fixed `Runtime.evaluate` calls returning strings to the caller | Only result type assertions | Low-volume data exfiltration from the current page; attacker controls returned strings |
+| `AngularHelper.GetRouterState` | `angular.go:251` | Page-controlled Angular router state returned from `Runtime.evaluate` | Parsed into `AngularRouterState` and returned to caller | Type assertions on expected string and map fields only | Exfiltration of route params, query params, and fragments from the SPA; large values can increase memory use |
+
+## Local Configuration Inputs That Amplify Exposure
+
+| Function | File:line | Input source | What it flows into | Current validation | Potential attack vector |
+|---|---|---|---|---|---|
+| `WithTimeout`, `AngularHelper.SetTimeout`, `WaitAction.Execute`, `ActionSequence.Wait` | `webview.go:93`<br>`angular.go:27`<br>`actions.go:59`<br>`actions.go:451` | Caller-supplied durations | Context deadlines and `time.After` waits | No range checks | Excessively long values can pin goroutines and prolong exposure windows; zero or negative values can short-circuit synchronisation logic |
+| `WithConsoleLimit`, `ConsoleWatcher.SetLimit` | `webview.go:102`<br>`console.go:72` | Caller-supplied message limits | In-memory retention size for console buffers | No lower or upper bound checks | Very large limits increase memory retention under noisy pages; low or negative values do not disable capture cleanly |

go.mod

@@ -1,5 +1,9 @@
-module forge.lthn.ai/core/go-webview
+module dappco.re/go/core/webview
 
 go 1.26.0
 
 require github.com/gorilla/websocket v1.5.3
+
+require dappco.re/go/core/log v0.1.0
+
+require dappco.re/go/core v0.8.0-alpha.1

go.sum

@@ -1,2 +1,14 @@
+dappco.re/go/core v0.8.0-alpha.1 h1:gj7+Scv+L63Z7wMxbJYHhaRFkHJo2u4MMPuUSv/Dhtk=
+dappco.re/go/core v0.8.0-alpha.1/go.mod h1:f2/tBZ3+3IqDrg2F5F598llv0nmb/4gJVCFzM5geE4A=
+dappco.re/go/core/log v0.1.0 h1:pa71Vq2TD2aoEUQWFKwNcaJ3GBY8HbaNGqtE688Unyc=
+dappco.re/go/core/log v0.1.0/go.mod h1:Nkqb8gsXhZAO8VLpx7B8i1iAmohhzqA20b9Zr8VUcJs=
+github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
+github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/gorilla/websocket v1.5.3 h1:saDtZ6Pbx/0u+bgYQ3q96pZgCzfhKXGPqt7kZ72aNNg=
 github.com/gorilla/websocket v1.5.3/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
+github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 h1:Jamvg5psRIccs7FGNTlIRMkT8wgtp5eCXdBlqhYGL6U=
+github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
+github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

specs/RFC.md

@@ -0,0 +1,505 @@
+# webview, **Import:** `dappco.re/go/core/webview`, **Files:** 5
+
+## Types
+
+### Action
+Declaration: `type Action interface`
+
+Browser action contract used by `ActionSequence`.
+
+Methods:
+- `Execute(ctx context.Context, wv *Webview) error`: Runs the action against the supplied `Webview` and caller-owned context.
+
+### ActionSequence
+Declaration: `type ActionSequence struct`
+
+Represents an ordered list of `Action` values. All fields are unexported.
+
+Methods:
+- `Add(action Action) *ActionSequence`: Appends `action` to the sequence and returns the same sequence for chaining.
+- `Click(selector string) *ActionSequence`: Appends `ClickAction{Selector: selector}`.
+- `Execute(ctx context.Context, wv *Webview) error`: Executes actions in insertion order. The first failing action stops execution and is wrapped as `ActionSequence.Execute` with the zero-based action index.
+- `Navigate(url string) *ActionSequence`: Appends `NavigateAction{URL: url}`.
+- `Type(selector, text string) *ActionSequence`: Appends `TypeAction{Selector: selector, Text: text}`.
+- `Wait(d time.Duration) *ActionSequence`: Appends `WaitAction{Duration: d}`.
+- `WaitForSelector(selector string) *ActionSequence`: Appends `WaitForSelectorAction{Selector: selector}`.
+
+### AngularHelper
+Declaration: `type AngularHelper struct`
+
+Angular-specific helper bound to a `Webview`. All fields are unexported. The helper stores the target `Webview` and a per-operation timeout, which defaults to 30 seconds in `NewAngularHelper`.
+
+Methods:
+- `CallComponentMethod(selector, methodName string, args ...any) (any, error)`: Looks up the Angular component instance for `selector`, verifies that `methodName` is callable, invokes it with JSON-marshalled arguments, ticks `ApplicationRef` when available, and returns the evaluated result.
+- `DispatchEvent(selector, eventName string, detail any) error`: Dispatches a bubbling `CustomEvent` on the matched element. `detail` is marshalled into the page script, or `null` when omitted.
+- `GetComponentProperty(selector, propertyName string) (any, error)`: Returns `componentInstance[propertyName]` for the Angular component attached to the matched element.
+- `GetNgModel(selector string) (any, error)`: Returns `element.value` for `input`, `select`, and `textarea` elements, otherwise `element.value || element.textContent`. Missing elements produce `nil`.
+- `GetRouterState() (*AngularRouterState, error)`: Walks Angular root elements, resolves the first available Router, and returns its URL, fragment, root params, and root query params. Only string values are copied into the returned maps.
+- `GetService(serviceName string) (any, error)`: Resolves a service from the first Angular root injector and returns `JSON.parse(JSON.stringify(service))`, so only JSON-serialisable data survives.
+- `NavigateByRouter(path string) error`: Resolves Angular Router from a root injector, calls `navigateByUrl(path)`, and then waits for Zone.js stability.
+- `SetComponentProperty(selector, propertyName string, value any) error`: Sets `componentInstance[propertyName]` and ticks `ApplicationRef` when available.
+- `SetNgModel(selector string, value any) error`: Assigns `element.value`, dispatches bubbling `input` and `change` events, and then ticks `ApplicationRef` on the first Angular root that exposes it.
+- `SetTimeout(d time.Duration)`: Replaces the helper's default timeout for later Angular operations.
+- `TriggerChangeDetection() error`: Tries to tick `ApplicationRef` on the first Angular root. The method only reports script-evaluation failures; a `false` result from the script is ignored.
+- `WaitForAngular() error`: Verifies that the page looks like an Angular application, then waits for Zone.js stability. It first tries an async Zone-based script and falls back to polling every 50 ms until the helper timeout expires.
+- `WaitForComponent(selector string) error`: Polls every 100 ms until `selector` resolves to an element with an Angular `componentInstance`, or until the helper timeout expires.
+
+### AngularRouterState
+Declaration: `type AngularRouterState struct`
+
+Represents the Angular Router state returned by `AngularHelper.GetRouterState`.
+
+Fields:
+- `URL string`: Current router URL.
+- `Fragment string`: Current URL fragment when Angular reports one.
+- `Params map[string]string`: Root route parameters copied from the router state.
+- `QueryParams map[string]string`: Root query parameters copied from the router state.
+
+### BlurAction
+Declaration: `type BlurAction struct`
+
+Removes focus from an element selected by CSS.
+
+Fields:
+- `Selector string`: CSS selector passed to `document.querySelector`.
+
+Methods:
+- `Execute(ctx context.Context, wv *Webview) error`: Runs `document.querySelector(Selector)?.blur()` through `wv.evaluate`.
+
+### BoundingBox
+Declaration: `type BoundingBox struct`
+
+Represents element coordinates derived from `DOM.getBoxModel`.
+
+Fields:
+- `X float64`: Left edge of the content box.
+- `Y float64`: Top edge of the content box.
+- `Width float64`: Width computed from the first and second X coordinates in the CDP content quad.
+- `Height float64`: Height computed from the first and third Y coordinates in the CDP content quad.
+
+### CDPClient
+Declaration: `type CDPClient struct`
+
+Low-level Chrome DevTools Protocol client backed by a single WebSocket connection. All fields are unexported.
+
+Methods:
+- `Call(ctx context.Context, method string, params map[string]any) (map[string]any, error)`: Clones `params`, assigns a monotonically increasing message ID, writes the request, and waits for the matching CDP response, `ctx.Done()`, or client shutdown.
+- `Close() error`: Cancels the client context, fails pending calls, closes the WebSocket, waits for the read loop to exit, and returns a wrapped close error only when the socket close itself fails with a non-terminal error.
+- `CloseTab() error`: Extracts the current target ID from the WebSocket URL, calls `Target.closeTarget`, checks `success` when the field is present, and then closes the client.
+- `DebugURL() string`: Returns the canonical debug HTTP URL stored on the client.
+- `NewTab(url string) (*CDPClient, error)`: Creates a target via `/json/new`, validates the returned WebSocket debugger URL, dials it, and returns a new `CDPClient`.
+- `OnEvent(method string, handler func(map[string]any))`: Registers a handler for a CDP event method name. Event dispatch clones the handler list and event params and invokes each handler in its own goroutine.
+- `Send(method string, params map[string]any) error`: Clones `params` and writes a fire-and-forget CDP message without waiting for a response.
+- `WebSocketURL() string`: Returns the target WebSocket URL currently in use.
+
+### CheckAction
+Declaration: `type CheckAction struct`
+
+Synchronises a checkbox state by clicking when the current `checked` state differs from the requested value.
+
+Fields:
+- `Selector string`: CSS selector for the checkbox element.
+- `Checked bool`: Desired checked state.
+
+Methods:
+- `Execute(ctx context.Context, wv *Webview) error`: Evaluates a script that clicks the element only when `el.checked != Checked`.
+
+### ClearAction
+Declaration: `type ClearAction struct`
+
+Clears the value of an input-like element.
+
+Fields:
+- `Selector string`: CSS selector for the target element.
+
+Methods:
+- `Execute(ctx context.Context, wv *Webview) error`: Sets `el.value = ""` and dispatches bubbling `input` and `change` events when the element exists.
+
+### ClickAction
+Declaration: `type ClickAction struct`
+
+Action wrapper for the `Webview` click implementation.
+
+Fields:
+- `Selector string`: CSS selector for the target element.
+
+Methods:
+- `Execute(ctx context.Context, wv *Webview) error`: Delegates to `wv.click(ctx, Selector)`.
+
+### ConsoleFilter
+Declaration: `type ConsoleFilter struct`
+
+Filter used by `ConsoleWatcher`.
+
+Fields:
+- `Type string`: Exact message-type match. The watcher compares it directly against `ConsoleMessage.Type`.
+- `Pattern string`: Case-sensitive substring match against `ConsoleMessage.Text`.
+
+### ConsoleHandler
+Declaration: `type ConsoleHandler func(msg ConsoleMessage)`
+
+Callback signature used by `ConsoleWatcher.AddHandler`.
+
+### ConsoleMessage
+Declaration: `type ConsoleMessage struct`
+
+Represents one console message captured from `Runtime.consoleAPICalled`.
+
+Fields:
+- `Type string`: Console message type reported by CDP.
+- `Text string`: Message text built by joining `args[*].value` with spaces.
+- `Timestamp time.Time`: Local capture time assigned in Go with `time.Now()`.
+- `URL string`: URL taken from the first stack-frame entry when present.
+- `Line int`: Line number taken from the first stack-frame entry when present.
+- `Column int`: Column number taken from the first stack-frame entry when present.
+
+### ConsoleWatcher
+Declaration: `type ConsoleWatcher struct`
+
+Higher-level console log collector layered on top of `Webview`. All fields are unexported. New watchers start with an empty message buffer and a default limit of 1000 messages.
+
+Methods:
+- `AddFilter(filter ConsoleFilter)`: Appends a filter. When at least one filter exists, `FilteredMessages` and `FilteredMessagesAll` use OR semantics across filters.
+- `AddHandler(handler ConsoleHandler)`: Registers a callback for future messages captured by this watcher.
+- `Clear()`: Removes all stored messages.
+- `ClearFilters()`: Removes every registered filter.
+- `Count() int`: Returns the current number of stored messages.
+- `ErrorCount() int`: Counts stored messages where `Type == "error"`.
+- `Errors() []ConsoleMessage`: Returns a collected slice of error messages.
+- `ErrorsAll() iter.Seq[ConsoleMessage]`: Returns an iterator that yields stored messages whose type is exactly `"error"`.
+- `FilteredMessages() []ConsoleMessage`: Returns a collected slice of messages that match the current filter set, or all messages when no filters exist.
+- `FilteredMessagesAll() iter.Seq[ConsoleMessage]`: Returns an iterator over the current filtered view.
+- `HasErrors() bool`: Reports whether any stored message has `Type == "error"`.
+- `Messages() []ConsoleMessage`: Returns a collected slice of all stored messages.
+- `MessagesAll() iter.Seq[ConsoleMessage]`: Returns an iterator over the stored message buffer.
+- `SetLimit(limit int)`: Replaces the retention limit used for future appends. Existing messages are only trimmed on later writes.
+- `WaitForError(ctx context.Context) (*ConsoleMessage, error)`: Equivalent to `WaitForMessage(ctx, ConsoleFilter{Type: "error"})`.
+- `WaitForMessage(ctx context.Context, filter ConsoleFilter) (*ConsoleMessage, error)`: Returns the first already-stored message that matches `filter`, otherwise registers a temporary handler and waits for the next matching message or `ctx.Done()`.
+- `Warnings() []ConsoleMessage`: Returns a collected slice of messages whose type is exactly `"warning"`.
+- `WarningsAll() iter.Seq[ConsoleMessage]`: Returns an iterator over stored messages whose type is exactly `"warning"`.
+
+### DoubleClickAction
+Declaration: `type DoubleClickAction struct`
+
+Double-click action for an element selected by CSS.
+
+Fields:
+- `Selector string`: CSS selector for the target element.
+
+Methods:
+- `Execute(ctx context.Context, wv *Webview) error`: Uses a JavaScript `dblclick` fallback when the element has no bounding box; otherwise sends two `mousePressed` and `mouseReleased` pairs with increasing `clickCount` values at the element centre.
+
+### ElementInfo
+Declaration: `type ElementInfo struct`
+
+Represents DOM metadata returned by `Webview.querySelector` and `Webview.querySelectorAll`.
+
+Fields:
+- `NodeID int`: CDP node ID used for later DOM operations.
+- `TagName string`: `nodeName` returned by `DOM.describeNode`.
+- `Attributes map[string]string`: Attributes parsed from the alternating key/value array returned by CDP.
+- `InnerHTML string`: Declared field for inner HTML content. The current implementation does not populate it.
+- `InnerText string`: Declared field for inner text content. The current implementation does not populate it.
+- `BoundingBox *BoundingBox`: Element box derived from `DOM.getBoxModel`. It is `nil` when box lookup fails.
+
+### ExceptionInfo
+Declaration: `type ExceptionInfo struct`
+
+Represents one `Runtime.exceptionThrown` event captured by `ExceptionWatcher`.
+
+Fields:
+- `Text string`: Exception text, overridden by `exception.description` when CDP provides one.
+- `LineNumber int`: Line number reported by CDP.
+- `ColumnNumber int`: Column number reported by CDP.
+- `URL string`: Source URL reported by CDP.
+- `StackTrace string`: Stack trace formatted in Go as one `at function (url:line:column)` line per call frame.
+- `Timestamp time.Time`: Local capture time assigned in Go with `time.Now()`.
+
+### ExceptionWatcher
+Declaration: `type ExceptionWatcher struct`
+
+Collector for JavaScript exceptions emitted by the bound `Webview`. All fields are unexported.
+
+Methods:
+- `AddHandler(handler func(ExceptionInfo))`: Registers a callback for future exception events.
+- `Clear()`: Removes all stored exceptions.
+- `Count() int`: Returns the current number of stored exceptions.
+- `Exceptions() []ExceptionInfo`: Returns a collected slice of all stored exceptions.
+- `ExceptionsAll() iter.Seq[ExceptionInfo]`: Returns an iterator over the stored exception buffer.
+- `HasExceptions() bool`: Reports whether any exceptions have been captured.
+- `WaitForException(ctx context.Context) (*ExceptionInfo, error)`: Returns the most recently stored exception immediately when one already exists; otherwise registers a temporary handler and waits for the next exception or `ctx.Done()`.
+
+### FocusAction
+Declaration: `type FocusAction struct`
+
+Moves focus to an element selected by CSS.
+
+Fields:
+- `Selector string`: CSS selector passed to `document.querySelector`.
+
+Methods:
+- `Execute(ctx context.Context, wv *Webview) error`: Runs `document.querySelector(Selector)?.focus()` through `wv.evaluate`.
+
+### HoverAction
+Declaration: `type HoverAction struct`
+
+Moves the mouse pointer over an element.
+
+Fields:
+- `Selector string`: CSS selector for the target element.
+
+Methods:
+- `Execute(ctx context.Context, wv *Webview) error`: Looks up the element, requires a non-nil bounding box, computes the box centre, and sends one `Input.dispatchMouseEvent` call with `type: "mouseMoved"`.
+
+### NavigateAction
+Declaration: `type NavigateAction struct`
+
+Action wrapper for page navigation.
+
+Fields:
+- `URL string`: URL passed to `Page.navigate`.
+
+Methods:
+- `Execute(ctx context.Context, wv *Webview) error`: Calls `Page.navigate` and then waits until `document.readyState == "complete"`.
+
+### Option
+Declaration: `type Option func(*Webview) error`
+
+Functional configuration hook applied by `New`. The exported option constructors are `WithDebugURL`, `WithTimeout`, and `WithConsoleLimit`.
+
+### PressKeyAction
+Declaration: `type PressKeyAction struct`
+
+Key-press action implemented through `Input.dispatchKeyEvent`.
+
+Fields:
+- `Key string`: Key name or character to send.
+
+Methods:
+- `Execute(ctx context.Context, wv *Webview) error`: Uses explicit CDP key metadata for common keys such as `Enter`, `Tab`, arrow keys, `Delete`, and paging keys. For any other string it sends a `keyDown` with `text: Key` followed by a bare `keyUp`.
+
+### RemoveAttributeAction
+Declaration: `type RemoveAttributeAction struct`
+
+Removes a DOM attribute.
+
+Fields:
+- `Selector string`: CSS selector for the target element.
+- `Attribute string`: Attribute name to remove.
+
+Methods:
+- `Execute(ctx context.Context, wv *Webview) error`: Runs `document.querySelector(Selector)?.removeAttribute(Attribute)` through `wv.evaluate`.
+
+### RightClickAction
+Declaration: `type RightClickAction struct`
+
+Context-click action for an element selected by CSS.
+
+Fields:
+- `Selector string`: CSS selector for the target element.
+
+Methods:
+- `Execute(ctx context.Context, wv *Webview) error`: Uses a JavaScript `contextmenu` fallback when the element has no bounding box; otherwise sends `mousePressed` and `mouseReleased` with `button: "right"` at the element centre.
+
+### ScrollAction
+Declaration: `type ScrollAction struct`
+
+Window scroll action.
+
+Fields:
+- `X int`: Horizontal scroll target passed to `window.scrollTo`.
+- `Y int`: Vertical scroll target passed to `window.scrollTo`.
+
+Methods:
+- `Execute(ctx context.Context, wv *Webview) error`: Evaluates `window.scrollTo(X, Y)`.
+
+### ScrollIntoViewAction
+Declaration: `type ScrollIntoViewAction struct`
+
+Scrolls a selected element into view.
+
+Fields:
+- `Selector string`: CSS selector for the target element.
+
+Methods:
+- `Execute(ctx context.Context, wv *Webview) error`: Evaluates `document.querySelector(Selector)?.scrollIntoView({behavior: "smooth", block: "center"})`.
+
+### SelectAction
+Declaration: `type SelectAction struct`
+
+Select-element value setter.
+
+Fields:
+- `Selector string`: CSS selector for the target element.
+- `Value string`: Option value assigned to `el.value`.
+
+Methods:
+- `Execute(ctx context.Context, wv *Webview) error`: Sets `el.value` and dispatches a bubbling `change` event when the element exists.
+
+### SetAttributeAction
+Declaration: `type SetAttributeAction struct`
+
+Sets a DOM attribute on the selected element.
+
+Fields:
+- `Selector string`: CSS selector for the target element.
+- `Attribute string`: Attribute name to set.
+- `Value string`: Attribute value passed to `setAttribute`.
+
+Methods:
+- `Execute(ctx context.Context, wv *Webview) error`: Runs `document.querySelector(Selector)?.setAttribute(Attribute, Value)` through `wv.evaluate`.
+
+### SetValueAction
+Declaration: `type SetValueAction struct`
+
+Directly sets an input-like value.
+
+Fields:
+- `Selector string`: CSS selector for the target element.
+- `Value string`: Value assigned to `el.value`.
+
+Methods:
+- `Execute(ctx context.Context, wv *Webview) error`: Sets `el.value` and dispatches bubbling `input` and `change` events when the element exists.
+
+### TargetInfo
+Declaration: `type TargetInfo struct`
+
+Represents one target entry returned by Chrome's `/json` and `/json/new` endpoints.
+
+Fields:
+- `ID string`: Chrome target ID.
+- `Type string`: Target type such as `page`.
+- `Title string`: Target title reported by Chrome.
+- `URL string`: Target URL reported by Chrome.
+- `WebSocketDebuggerURL string`: WebSocket debugger URL for the target.
+
+### TypeAction
+Declaration: `type TypeAction struct`
+
+Action wrapper for `Webview` text entry.
+
+Fields:
+- `Selector string`: CSS selector for the target element.
+- `Text string`: Text sent one rune at a time.
+
+Methods:
+- `Execute(ctx context.Context, wv *Webview) error`: Delegates to `wv.typeText(ctx, Selector, Text)`.
+
+### WaitAction
+Declaration: `type WaitAction struct`
+
+Time-based delay action.
+
+Fields:
+- `Duration time.Duration`: Delay length.
+
+Methods:
+- `Execute(ctx context.Context, wv *Webview) error`: Waits for `Duration` with `time.After`, but returns `ctx.Err()` immediately if the context is cancelled first.
+
+### WaitForSelectorAction
+Declaration: `type WaitForSelectorAction struct`
+
+Action wrapper for selector polling.
+
+Fields:
+- `Selector string`: CSS selector to wait for.
+
+Methods:
+- `Execute(ctx context.Context, wv *Webview) error`: Delegates to `wv.waitForSelector(ctx, Selector)`.
+
+### Webview
+Declaration: `type Webview struct`
+
+High-level browser automation client built on `CDPClient`. All fields are unexported. Instances created by `New` carry a default timeout of 30 seconds and a default console retention limit of 1000 messages.
+
+Methods:
+- `ClearConsole()`: Removes all console messages stored on the `Webview`.
+- `Click(selector string) error`: Creates a timeout-scoped context and delegates to the internal click path. The internal click logic queries the element, uses a JavaScript `.click()` fallback when there is no bounding box, and otherwise sends left-button press and release events at the element centre.
+- `Close() error`: Cancels the `Webview` context and closes the underlying `CDPClient` when one exists.
+- `DragAndDrop(sourceSelector, targetSelector string) error`: Looks up both elements, requires bounding boxes for both, then sends `mousePressed` at the source centre, `mouseMoved` to the target centre, and `mouseReleased` at the target centre.
+- `Evaluate(script string) (any, error)`: Evaluates JavaScript through `Runtime.evaluate` with `returnByValue: true` and `awaitPromise: true`. When CDP reports `exceptionDetails`, the method returns a wrapped JavaScript error.
+- `GetConsole() []ConsoleMessage`: Returns a collected slice of stored console messages.
+- `GetConsoleAll() iter.Seq[ConsoleMessage]`: Returns an iterator over the stored console message buffer.
+- `GetHTML(selector string) (string, error)`: Returns `document.documentElement.outerHTML` when `selector` is empty; otherwise returns `document.querySelector(selector)?.outerHTML || ""`.
+- `GetTitle() (string, error)`: Evaluates `document.title` and requires the result to be a string.
+- `GetURL() (string, error)`: Evaluates `window.location.href` and requires the result to be a string.
+- `GoBack() error`: Calls `Page.goBackOrForward` with `delta: -1`.
+- `GoForward() error`: Calls `Page.goBackOrForward` with `delta: 1`.
+- `Navigate(url string) error`: Calls `Page.navigate` and then polls `document.readyState` every 100 ms until it becomes `"complete"` or the timeout expires.
+- `QuerySelector(selector string) (*ElementInfo, error)`: Fetches the document root, runs `DOM.querySelector`, errors when the selector does not resolve, and returns `ElementInfo` for the matched node.
+- `QuerySelectorAll(selector string) ([]*ElementInfo, error)`: Runs `DOM.querySelectorAll` and returns one `ElementInfo` per node ID whose metadata lookup succeeds. Nodes whose metadata fetch fails are skipped.
+- `QuerySelectorAllAll(selector string) iter.Seq[*ElementInfo]`: Returns an iterator that runs `QuerySelectorAll` under the `Webview` timeout and yields each element. Errors produce an empty iterator.
+- `Reload() error`: Calls `Page.reload` and then waits for `document.readyState == "complete"`.
+- `Screenshot() ([]byte, error)`: Calls `Page.captureScreenshot` with `format: "png"`, decodes the returned base64 payload, and returns the PNG bytes.
+- `SetUserAgent(userAgent string) error`: Calls `Emulation.setUserAgentOverride`.
+- `SetViewport(width, height int) error`: Calls `Emulation.setDeviceMetricsOverride` with the supplied size, `deviceScaleFactor: 1`, and `mobile: false`.
+- `Type(selector, text string) error`: Creates a timeout-scoped context and delegates to the internal typing path. The internal logic focuses the element with JavaScript, then sends one `keyDown` with `text` and one `keyUp` per rune in `text`.
+- `UploadFile(selector string, filePaths []string) error`: Resolves the target node with `QuerySelector` and passes its node ID to `DOM.setFileInputFiles`.
+- `WaitForSelector(selector string) error`: Polls `!!document.querySelector(selector)` every 100 ms until it becomes true or the timeout expires.
+
+## Functions
+
+### FormatConsoleOutput
+`func FormatConsoleOutput(messages []ConsoleMessage) string`
+
+Formats each message as `HH:MM:SS.mmm [PREFIX] text\n`. Prefixes are `[ERROR]` for `error`, `[WARN]` for `warning`, `[INFO]` for `info`, `[DEBUG]` for `debug`, and `[LOG]` for every other type.
+
+### GetVersion
+`func GetVersion(debugURL string) (map[string]string, error)`
+
+Validates `debugURL`, requests `/json/version`, and decodes the response body into `map[string]string`.
+
+### ListTargets
+`func ListTargets(debugURL string) ([]TargetInfo, error)`
+
+Validates `debugURL`, requests `/json`, and decodes the response body into a slice of `TargetInfo`.
+
+### ListTargetsAll
+`func ListTargetsAll(debugURL string) iter.Seq[TargetInfo]`
+
+Iterator wrapper around `ListTargets`. When `ListTargets` fails, the iterator yields no values.
+
+### New
+`func New(opts ...Option) (*Webview, error)`
+
+Creates a `Webview`, applies `opts` in order, requires an option that installs a `CDPClient`, enables the `Runtime`, `Page`, and `DOM` domains, and subscribes console capture. On any option or initialisation failure it cancels the context and closes the client when one was created.
+
+### NewActionSequence
+`func NewActionSequence() *ActionSequence`
+
+Creates an empty `ActionSequence`.
+
+### NewAngularHelper
+`func NewAngularHelper(wv *Webview) *AngularHelper`
+
+Creates an `AngularHelper` bound to `wv` with a 30-second default timeout.
+
+### NewCDPClient
+`func NewCDPClient(debugURL string) (*CDPClient, error)`
+
+Validates that `debugURL` is an `http` or `https` DevTools root URL with no credentials, query, fragment, or non-root path. The function requests `/json`, picks the first `page` target with a debugger WebSocket URL, creates a new target via `/json/new` when none exists, validates that the WebSocket host matches the debug host, dials the socket, and starts the client's read loop.
+
+### NewConsoleWatcher
+`func NewConsoleWatcher(wv *Webview) *ConsoleWatcher`
+
+Creates a `ConsoleWatcher`, initialises an empty message buffer with a 1000-message limit, and subscribes it to `Runtime.consoleAPICalled` events on `wv.client`.
+
+### NewExceptionWatcher
+`func NewExceptionWatcher(wv *Webview) *ExceptionWatcher`
+
+Creates an `ExceptionWatcher`, initialises an empty exception buffer, and subscribes it to `Runtime.exceptionThrown` events on `wv.client`.
+
+### WithConsoleLimit
+`func WithConsoleLimit(limit int) Option`
+
+Returns an `Option` that replaces `Webview.consoleLimit`. The default used by `New` is 1000.
+
+### WithDebugURL
+`func WithDebugURL(url string) Option`
+
+Returns an `Option` that dials a `CDPClient` immediately and stores it on the `Webview`.
+
+### WithTimeout
+`func WithTimeout(d time.Duration) Option`
+
+Returns an `Option` that replaces the default per-operation timeout used by `Webview` methods.

webview.go

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: EUPL-1.2
 // Package webview provides browser automation via Chrome DevTools Protocol (CDP).
 //
 // The package allows controlling Chrome/Chromium browsers for automated testing,
@@ -24,12 +25,13 @@ package webview
 import (
 	"context"
 	"encoding/base64"
-	"fmt"
 	"iter"
 	"slices"
-	"strings"
 	"sync"
 	"time"
+
+	core "dappco.re/go/core"
+	coreerr "dappco.re/go/core/log"
 )
 
 // Webview represents a connection to a Chrome DevTools Protocol endpoint.
@@ -80,7 +82,7 @@ func WithDebugURL(url string) Option {
 	return func(wv *Webview) error {
 		client, err := NewCDPClient(url)
 		if err != nil {
-			return fmt.Errorf("failed to connect to Chrome DevTools: %w", err)
+			return coreerr.E("Webview.WithDebugURL", "failed to connect to Chrome DevTools", err)
 		}
 		wv.client = client
 		return nil
@@ -112,26 +114,33 @@ func New(opts ...Option) (*Webview, error) {
 		ctx:          ctx,
 		cancel:       cancel,
 		timeout:      30 * time.Second,
-		consoleLogs:  make([]ConsoleMessage, 0, 100),
+		consoleLogs:  make([]ConsoleMessage, 0, 1000),
 		consoleLimit: 1000,
 	}
 
+	cleanupOnError := func() {
+		cancel()
+		if wv.client != nil {
+			_ = wv.client.Close()
+		}
+	}
+
 	for _, opt := range opts {
 		if err := opt(wv); err != nil {
-			cancel()
+			cleanupOnError()
 			return nil, err
 		}
 	}
 
 	if wv.client == nil {
 		cancel()
-		return nil, fmt.Errorf("no debug URL provided; use WithDebugURL option")
+		return nil, coreerr.E("Webview.New", "no debug URL provided; use WithDebugURL option", nil)
 	}
 
 	// Enable console capture
 	if err := wv.enableConsole(); err != nil {
-		cancel()
-		return nil, fmt.Errorf("failed to enable console capture: %w", err)
+		cleanupOnError()
+		return nil, coreerr.E("Webview.New", "failed to enable console capture", err)
 	}
 
 	return wv, nil
@@ -155,7 +164,7 @@ func (wv *Webview) Navigate(url string) error {
 		"url": url,
 	})
 	if err != nil {
-		return fmt.Errorf("failed to navigate: %w", err)
+		return coreerr.E("Webview.Navigate", "failed to navigate", err)
 	}
 
 	// Wait for page load
@@ -248,17 +257,17 @@ func (wv *Webview) Screenshot() ([]byte, error) {
 		"format": "png",
 	})
 	if err != nil {
-		return nil, fmt.Errorf("failed to capture screenshot: %w", err)
+		return nil, coreerr.E("Webview.Screenshot", "failed to capture screenshot", err)
 	}
 
 	dataStr, ok := result["data"].(string)
 	if !ok {
-		return nil, fmt.Errorf("invalid screenshot data")
+		return nil, coreerr.E("Webview.Screenshot", "invalid screenshot data", nil)
 	}
 
 	data, err := base64.StdEncoding.DecodeString(dataStr)
 	if err != nil {
-		return nil, fmt.Errorf("failed to decode screenshot: %w", err)
+		return nil, coreerr.E("Webview.Screenshot", "failed to decode screenshot", err)
 	}
 
 	return data, nil
@@ -294,7 +303,7 @@ func (wv *Webview) GetURL() (string, error) {
 
 	url, ok := result.(string)
 	if !ok {
-		return "", fmt.Errorf("invalid URL result")
+		return "", coreerr.E("Webview.GetURL", "invalid URL result", nil)
 	}
 
 	return url, nil
@@ -312,7 +321,7 @@ func (wv *Webview) GetTitle() (string, error) {
 
 	title, ok := result.(string)
 	if !ok {
-		return "", fmt.Errorf("invalid title result")
+		return "", coreerr.E("Webview.GetTitle", "invalid title result", nil)
 	}
 
 	return title, nil
@@ -327,7 +336,7 @@ func (wv *Webview) GetHTML(selector string) (string, error) {
 	if selector == "" {
 		script = "document.documentElement.outerHTML"
 	} else {
-		script = fmt.Sprintf("document.querySelector(%q)?.outerHTML || ''", selector)
+		script = core.Sprintf("document.querySelector(%q)?.outerHTML || ''", selector)
 	}
 
 	result, err := wv.evaluate(ctx, script)
@@ -337,7 +346,7 @@ func (wv *Webview) GetHTML(selector string) (string, error) {
 
 	html, ok := result.(string)
 	if !ok {
-		return "", fmt.Errorf("invalid HTML result")
+		return "", coreerr.E("Webview.GetHTML", "invalid HTML result", nil)
 	}
 
 	return html, nil
@@ -375,7 +384,7 @@ func (wv *Webview) Reload() error {
 
 	_, err := wv.client.Call(ctx, "Page.reload", nil)
 	if err != nil {
-		return fmt.Errorf("failed to reload: %w", err)
+		return coreerr.E("Webview.Reload", "failed to reload", err)
 	}
 
 	return wv.waitForLoad(ctx)
@@ -410,7 +419,8 @@ func (wv *Webview) addConsoleMessage(msg ConsoleMessage) {
 
 	if len(wv.consoleLogs) >= wv.consoleLimit {
 		// Remove oldest messages
-		wv.consoleLogs = wv.consoleLogs[len(wv.consoleLogs)-wv.consoleLimit+100:]
+		drop := min(100, len(wv.consoleLogs))
+		wv.consoleLogs = wv.consoleLogs[drop:]
 	}
 	wv.consoleLogs = append(wv.consoleLogs, msg)
 }
@@ -452,14 +462,14 @@ func (wv *Webview) handleConsoleEvent(params map[string]any) {
 
 	// Extract args
 	args, _ := params["args"].([]any)
-	var text strings.Builder
+	text := core.NewBuilder()
 	for i, arg := range args {
 		if argMap, ok := arg.(map[string]any); ok {
 			if val, ok := argMap["value"]; ok {
 				if i > 0 {
 					text.WriteString(" ")
 				}
-				text.WriteString(fmt.Sprint(val))
+				text.WriteString(core.Sprint(val))
 			}
 		}
 	}
@@ -515,7 +525,7 @@ func (wv *Webview) waitForSelector(ctx context.Context, selector string) error {
 	ticker := time.NewTicker(100 * time.Millisecond)
 	defer ticker.Stop()
 
-	script := fmt.Sprintf("!!document.querySelector(%q)", selector)
+	script := core.Sprintf("!!document.querySelector(%q)", selector)
 
 	for {
 		select {
@@ -539,19 +549,20 @@ func (wv *Webview) evaluate(ctx context.Context, script string) (any, error) {
 	result, err := wv.client.Call(ctx, "Runtime.evaluate", map[string]any{
 		"expression":    script,
 		"returnByValue": true,
+		"awaitPromise":  true,
 	})
 	if err != nil {
-		return nil, fmt.Errorf("failed to evaluate script: %w", err)
+		return nil, coreerr.E("Webview.evaluate", "failed to evaluate script", err)
 	}
 
 	// Check for exception
 	if exceptionDetails, ok := result["exceptionDetails"].(map[string]any); ok {
 		if exception, ok := exceptionDetails["exception"].(map[string]any); ok {
 			if description, ok := exception["description"].(string); ok {
-				return nil, fmt.Errorf("JavaScript error: %s", description)
+				return nil, coreerr.E("Webview.evaluate", description, nil)
 			}
 		}
-		return nil, fmt.Errorf("JavaScript error")
+		return nil, coreerr.E("Webview.evaluate", "JavaScript error", nil)
 	}
 
 	// Extract result value
@@ -567,17 +578,17 @@ func (wv *Webview) querySelector(ctx context.Context, selector string) (*Element
 	// Get document root
 	docResult, err := wv.client.Call(ctx, "DOM.getDocument", nil)
 	if err != nil {
-		return nil, fmt.Errorf("failed to get document: %w", err)
+		return nil, coreerr.E("Webview.querySelector", "failed to get document", err)
 	}
 
 	root, ok := docResult["root"].(map[string]any)
 	if !ok {
-		return nil, fmt.Errorf("invalid document root")
+		return nil, coreerr.E("Webview.querySelector", "invalid document root", nil)
 	}
 
 	rootID, ok := root["nodeId"].(float64)
 	if !ok {
-		return nil, fmt.Errorf("invalid root node ID")
+		return nil, coreerr.E("Webview.querySelector", "invalid root node ID", nil)
 	}
 
 	// Query selector
@@ -586,12 +597,12 @@ func (wv *Webview) querySelector(ctx context.Context, selector string) (*Element
 		"selector": selector,
 	})
 	if err != nil {
-		return nil, fmt.Errorf("failed to query selector: %w", err)
+		return nil, coreerr.E("Webview.querySelector", "failed to query selector", err)
 	}
 
 	nodeID, ok := queryResult["nodeId"].(float64)
 	if !ok || nodeID == 0 {
-		return nil, fmt.Errorf("element not found: %s", selector)
+		return nil, coreerr.E("Webview.querySelector", "element not found: "+selector, nil)
 	}
 
 	return wv.getElementInfo(ctx, int(nodeID))
@@ -602,17 +613,17 @@ func (wv *Webview) querySelectorAll(ctx context.Context, selector string) ([]*El
 	// Get document root
 	docResult, err := wv.client.Call(ctx, "DOM.getDocument", nil)
 	if err != nil {
-		return nil, fmt.Errorf("failed to get document: %w", err)
+		return nil, coreerr.E("Webview.querySelectorAll", "failed to get document", err)
 	}
 
 	root, ok := docResult["root"].(map[string]any)
 	if !ok {
-		return nil, fmt.Errorf("invalid document root")
+		return nil, coreerr.E("Webview.querySelectorAll", "invalid document root", nil)
 	}
 
 	rootID, ok := root["nodeId"].(float64)
 	if !ok {
-		return nil, fmt.Errorf("invalid root node ID")
+		return nil, coreerr.E("Webview.querySelectorAll", "invalid root node ID", nil)
 	}
 
 	// Query selector all
@@ -621,12 +632,12 @@ func (wv *Webview) querySelectorAll(ctx context.Context, selector string) ([]*El
 		"selector": selector,
 	})
 	if err != nil {
-		return nil, fmt.Errorf("failed to query selector all: %w", err)
+		return nil, coreerr.E("Webview.querySelectorAll", "failed to query selector all", err)
 	}
 
 	nodeIDs, ok := queryResult["nodeIds"].([]any)
 	if !ok {
-		return nil, fmt.Errorf("invalid node IDs")
+		return nil, coreerr.E("Webview.querySelectorAll", "invalid node IDs", nil)
 	}
 
 	elements := make([]*ElementInfo, 0, len(nodeIDs))
@@ -653,7 +664,7 @@ func (wv *Webview) getElementInfo(ctx context.Context, nodeID int) (*ElementInfo
 
 	node, ok := descResult["node"].(map[string]any)
 	if !ok {
-		return nil, fmt.Errorf("invalid node description")
+		return nil, coreerr.E("Webview.getElementInfo", "invalid node description", nil)
 	}
 
 	tagName, _ := node["nodeName"].(string)
@@ -668,6 +679,8 @@ func (wv *Webview) getElementInfo(ctx context.Context, nodeID int) (*ElementInfo
 		}
 	}
 
+	innerHTML, innerText := wv.getElementContent(ctx, nodeID)
+
 	// Get bounding box
 	var box *BoundingBox
 	if boxResult, err := wv.client.Call(ctx, "DOM.getBoxModel", map[string]any{
@@ -693,10 +706,61 @@ func (wv *Webview) getElementInfo(ctx context.Context, nodeID int) (*ElementInfo
 		NodeID:      nodeID,
 		TagName:     tagName,
 		Attributes:  attrs,
+		InnerHTML:   innerHTML,
+		InnerText:   innerText,
 		BoundingBox: box,
 	}, nil
 }
 
+// getElementContent retrieves the element's inner HTML and inner text.
+func (wv *Webview) getElementContent(ctx context.Context, nodeID int) (string, string) {
+	resolveResult, err := wv.client.Call(ctx, "DOM.resolveNode", map[string]any{
+		"nodeId": nodeID,
+	})
+	if err != nil {
+		return "", ""
+	}
+
+	object, ok := resolveResult["object"].(map[string]any)
+	if !ok {
+		return "", ""
+	}
+
+	objectID, ok := object["objectId"].(string)
+	if !ok || objectID == "" {
+		return "", ""
+	}
+
+	callResult, err := wv.client.Call(ctx, "Runtime.callFunctionOn", map[string]any{
+		"objectId":            objectID,
+		"functionDeclaration": "function() { return { innerHTML: this.innerHTML || '', innerText: this.innerText || '' }; }",
+		"returnByValue":       true,
+		"awaitPromise":        true,
+	})
+	if err != nil {
+		return "", ""
+	}
+
+	return parseElementContent(callResult)
+}
+
+// parseElementContent extracts inner HTML and inner text from a CDP response.
+func parseElementContent(result map[string]any) (string, string) {
+	resultObj, ok := result["result"].(map[string]any)
+	if !ok {
+		return "", ""
+	}
+
+	value, ok := resultObj["value"].(map[string]any)
+	if !ok {
+		return "", ""
+	}
+
+	innerHTML, _ := value["innerHTML"].(string)
+	innerText, _ := value["innerText"].(string)
+	return innerHTML, innerText
+}
+
 // click performs a click on an element.
 func (wv *Webview) click(ctx context.Context, selector string) error {
 	// Find element and get its center coordinates
@@ -707,7 +771,7 @@ func (wv *Webview) click(ctx context.Context, selector string) error {
 
 	if elem.BoundingBox == nil {
 		// Fallback to JavaScript click
-		script := fmt.Sprintf("document.querySelector(%q)?.click()", selector)
+		script := core.Sprintf("document.querySelector(%q)?.click()", selector)
 		_, err := wv.evaluate(ctx, script)
 		return err
 	}
@@ -726,7 +790,7 @@ func (wv *Webview) click(ctx context.Context, selector string) error {
 			"clickCount": 1,
 		})
 		if err != nil {
-			return fmt.Errorf("failed to dispatch %s: %w", eventType, err)
+			return coreerr.E("Webview.click", "failed to dispatch "+eventType, err)
 		}
 	}
 
@@ -736,10 +800,10 @@ func (wv *Webview) click(ctx context.Context, selector string) error {
 // typeText types text into an element.
 func (wv *Webview) typeText(ctx context.Context, selector, text string) error {
 	// Focus the element first
-	script := fmt.Sprintf("document.querySelector(%q)?.focus()", selector)
+	script := core.Sprintf("document.querySelector(%q)?.focus()", selector)
 	_, err := wv.evaluate(ctx, script)
 	if err != nil {
-		return fmt.Errorf("failed to focus element: %w", err)
+		return coreerr.E("Webview.typeText", "failed to focus element", err)
 	}
 
 	// Type each character
@@ -749,14 +813,14 @@ func (wv *Webview) typeText(ctx context.Context, selector, text string) error {
 			"text": string(char),
 		})
 		if err != nil {
-			return fmt.Errorf("failed to dispatch keyDown: %w", err)
+			return coreerr.E("Webview.typeText", "failed to dispatch keyDown", err)
 		}
 
 		_, err = wv.client.Call(ctx, "Input.dispatchKeyEvent", map[string]any{
 			"type": "keyUp",
 		})
 		if err != nil {
-			return fmt.Errorf("failed to dispatch keyUp: %w", err)
+			return coreerr.E("Webview.typeText", "failed to dispatch keyUp", err)
 		}
 	}
 

webview_test.go

@@ -1,6 +1,8 @@
+// SPDX-License-Identifier: EUPL-1.2
 package webview
 
 import (
+	"context"
 	"testing"
 	"time"
 )
@@ -333,3 +335,453 @@ func TestScrollIntoViewAction_Good(t *testing.T) {
 		t.Errorf("Expected selector '#target', got %q", action.Selector)
 	}
 }
+
+// TestFormatConsoleOutput_Good verifies console output formatting.
+func TestFormatConsoleOutput_Good(t *testing.T) {
+	ts := time.Date(2026, 1, 15, 14, 30, 45, 123000000, time.UTC)
+	messages := []ConsoleMessage{
+		{Type: "error", Text: "something broke", Timestamp: ts},
+		{Type: "warning", Text: "deprecated call", Timestamp: ts},
+		{Type: "info", Text: "loaded", Timestamp: ts},
+		{Type: "debug", Text: "trace data", Timestamp: ts},
+		{Type: "log", Text: "hello world", Timestamp: ts},
+	}
+
+	output := FormatConsoleOutput(messages)
+
+	expected := []string{
+		"14:30:45.123 [ERROR] something broke",
+		"14:30:45.123 [WARN] deprecated call",
+		"14:30:45.123 [INFO] loaded",
+		"14:30:45.123 [DEBUG] trace data",
+		"14:30:45.123 [LOG] hello world",
+	}
+	for _, exp := range expected {
+		if !containsString(output, exp) {
+			t.Errorf("Expected output to contain %q", exp)
+		}
+	}
+}
+
+// TestFormatConsoleOutput_Good_Empty verifies empty message list.
+func TestFormatConsoleOutput_Good_Empty(t *testing.T) {
+	output := FormatConsoleOutput(nil)
+	if output != "" {
+		t.Errorf("Expected empty string, got %q", output)
+	}
+}
+
+// TestContainsString_Good verifies substring matching.
+func TestContainsString_Good(t *testing.T) {
+	tests := []struct {
+		s, substr string
+		want      bool
+	}{
+		{"hello world", "world", true},
+		{"hello world", "hello", true},
+		{"hello world", "xyz", false},
+		{"hello", "", true},
+		{"", "", true},
+		{"", "a", false},
+		{"abc", "abc", true},
+		{"abc", "abcd", false},
+	}
+
+	for _, tc := range tests {
+		got := containsString(tc.s, tc.substr)
+		if got != tc.want {
+			t.Errorf("containsString(%q, %q) = %v, want %v", tc.s, tc.substr, got, tc.want)
+		}
+	}
+}
+
+// TestFindString_Good verifies string search.
+func TestFindString_Good(t *testing.T) {
+	tests := []struct {
+		s, substr string
+		want      int
+	}{
+		{"hello world", "world", 6},
+		{"hello world", "hello", 0},
+		{"hello world", "xyz", -1},
+		{"abcabc", "abc", 0},
+		{"abc", "abc", 0},
+	}
+
+	for _, tc := range tests {
+		got := findString(tc.s, tc.substr)
+		if got != tc.want {
+			t.Errorf("findString(%q, %q) = %d, want %d", tc.s, tc.substr, got, tc.want)
+		}
+	}
+}
+
+// TestFormatJSValue_Good verifies JavaScript value formatting.
+func TestFormatJSValue_Good(t *testing.T) {
+	tests := []struct {
+		input any
+		want  string
+	}{
+		{"hello", `"hello"`},
+		{true, "true"},
+		{false, "false"},
+		{nil, "null"},
+		{42, "42"},
+		{3.14, "3.14"},
+		{map[string]any{"enabled": true}, `{"enabled":true}`},
+		{[]any{1, "two"}, `[1,"two"]`},
+	}
+
+	for _, tc := range tests {
+		got := formatJSValue(tc.input)
+		if got != tc.want {
+			t.Errorf("formatJSValue(%v) = %q, want %q", tc.input, got, tc.want)
+		}
+	}
+}
+
+// TestGetString_Good verifies map string extraction.
+func TestGetString_Good(t *testing.T) {
+	m := map[string]any{
+		"name":  "test",
+		"count": 42,
+	}
+
+	if got := getString(m, "name"); got != "test" {
+		t.Errorf("getString(m, 'name') = %q, want 'test'", got)
+	}
+	if got := getString(m, "count"); got != "" {
+		t.Errorf("getString(m, 'count') = %q, want empty (not a string)", got)
+	}
+	if got := getString(m, "missing"); got != "" {
+		t.Errorf("getString(m, 'missing') = %q, want empty", got)
+	}
+}
+
+// TestParseElementContent_Good verifies inner content extraction from CDP output.
+func TestParseElementContent_Good(t *testing.T) {
+	result := map[string]any{
+		"result": map[string]any{
+			"value": map[string]any{
+				"innerHTML": "<span>Hello</span>",
+				"innerText": "Hello",
+			},
+		},
+	}
+
+	innerHTML, innerText := parseElementContent(result)
+	if innerHTML != "<span>Hello</span>" {
+		t.Fatalf("parseElementContent innerHTML = %q, want %q", innerHTML, "<span>Hello</span>")
+	}
+	if innerText != "Hello" {
+		t.Fatalf("parseElementContent innerText = %q, want %q", innerText, "Hello")
+	}
+}
+
+// TestWaitAction_Good_ContextCancelled verifies WaitAction respects context cancellation.
+func TestWaitAction_Good_ContextCancelled(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel() // Cancel immediately
+
+	action := WaitAction{Duration: 10 * time.Second}
+	err := action.Execute(ctx, nil)
+	if err == nil {
+		t.Error("Expected context cancelled error")
+	}
+}
+
+// TestWaitAction_Good_ShortWait verifies WaitAction completes after duration.
+func TestWaitAction_Good_ShortWait(t *testing.T) {
+	ctx := context.Background()
+	action := WaitAction{Duration: 10 * time.Millisecond}
+
+	start := time.Now()
+	err := action.Execute(ctx, nil)
+	elapsed := time.Since(start)
+
+	if err != nil {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+	if elapsed < 10*time.Millisecond {
+		t.Errorf("Expected at least 10ms elapsed, got %v", elapsed)
+	}
+}
+
+// TestAddConsoleMessage_Good verifies console message buffer management.
+func TestAddConsoleMessage_Good(t *testing.T) {
+	wv := &Webview{
+		consoleLogs:  make([]ConsoleMessage, 0, 10),
+		consoleLimit: 5,
+	}
+
+	// Add messages up to the limit
+	for i := range 6 {
+		wv.addConsoleMessage(ConsoleMessage{
+			Type: "log",
+			Text: time.Duration(i).String(),
+		})
+	}
+
+	// Buffer should have been trimmed
+	if len(wv.consoleLogs) > wv.consoleLimit {
+		t.Errorf("Expected at most %d messages, got %d", wv.consoleLimit, len(wv.consoleLogs))
+	}
+}
+
+// TestConsoleWatcherFilter_Good verifies console watcher filter matching.
+func TestConsoleWatcherFilter_Good(t *testing.T) {
+	// Create a minimal ConsoleWatcher without a real Webview
+	cw := &ConsoleWatcher{
+		messages: make([]ConsoleMessage, 0),
+		filters:  make([]ConsoleFilter, 0),
+		limit:    1000,
+		handlers: make([]consoleHandlerRegistration, 0),
+	}
+
+	// No filters — everything matches
+	msg := ConsoleMessage{Type: "error", Text: "test error"}
+	if !cw.matchesFilter(msg) {
+		t.Error("Expected message to match with no filters")
+	}
+
+	// Add type filter
+	cw.AddFilter(ConsoleFilter{Type: "error"})
+	if !cw.matchesFilter(msg) {
+		t.Error("Expected error message to match error filter")
+	}
+
+	logMsg := ConsoleMessage{Type: "log", Text: "test log"}
+	if cw.matchesFilter(logMsg) {
+		t.Error("Expected log message NOT to match error filter")
+	}
+
+	// Add pattern filter
+	cw.ClearFilters()
+	cw.AddFilter(ConsoleFilter{Pattern: "hello"})
+	helloMsg := ConsoleMessage{Type: "log", Text: "hello world"}
+	if !cw.matchesFilter(helloMsg) {
+		t.Error("Expected 'hello world' to match pattern 'hello'")
+	}
+	if cw.matchesFilter(msg) {
+		t.Error("Expected 'test error' NOT to match pattern 'hello'")
+	}
+}
+
+// TestConsoleWatcherCounts_Good verifies console watcher counting methods.
+func TestConsoleWatcherCounts_Good(t *testing.T) {
+	cw := &ConsoleWatcher{
+		messages: []ConsoleMessage{
+			{Type: "log", Text: "info 1"},
+			{Type: "error", Text: "err 1"},
+			{Type: "log", Text: "info 2"},
+			{Type: "error", Text: "err 2"},
+			{Type: "warning", Text: "warn 1"},
+		},
+		filters:  make([]ConsoleFilter, 0),
+		limit:    1000,
+		handlers: make([]consoleHandlerRegistration, 0),
+	}
+
+	if cw.Count() != 5 {
+		t.Errorf("Expected count 5, got %d", cw.Count())
+	}
+	if cw.ErrorCount() != 2 {
+		t.Errorf("Expected error count 2, got %d", cw.ErrorCount())
+	}
+	if !cw.HasErrors() {
+		t.Error("Expected HasErrors() to be true")
+	}
+
+	errors := cw.Errors()
+	if len(errors) != 2 {
+		t.Errorf("Expected 2 errors, got %d", len(errors))
+	}
+
+	warnings := cw.Warnings()
+	if len(warnings) != 1 {
+		t.Errorf("Expected 1 warning, got %d", len(warnings))
+	}
+
+	cw.Clear()
+	if cw.Count() != 0 {
+		t.Errorf("Expected count 0 after clear, got %d", cw.Count())
+	}
+	if cw.HasErrors() {
+		t.Error("Expected HasErrors() to be false after clear")
+	}
+}
+
+// TestExceptionWatcher_Good verifies exception watcher basic operations.
+func TestExceptionWatcher_Good(t *testing.T) {
+	ew := &ExceptionWatcher{
+		exceptions: make([]ExceptionInfo, 0),
+		handlers:   make([]exceptionHandlerRegistration, 0),
+	}
+
+	if ew.HasExceptions() {
+		t.Error("Expected no exceptions initially")
+	}
+	if ew.Count() != 0 {
+		t.Errorf("Expected count 0, got %d", ew.Count())
+	}
+
+	// Simulate adding an exception
+	ew.exceptions = append(ew.exceptions, ExceptionInfo{
+		Text:       "TypeError: undefined is not a function",
+		LineNumber: 10,
+		URL:        "https://example.com/app.js",
+	})
+
+	if !ew.HasExceptions() {
+		t.Error("Expected HasExceptions() to be true")
+	}
+	if ew.Count() != 1 {
+		t.Errorf("Expected count 1, got %d", ew.Count())
+	}
+
+	exceptions := ew.Exceptions()
+	if len(exceptions) != 1 {
+		t.Errorf("Expected 1 exception, got %d", len(exceptions))
+	}
+	if exceptions[0].Text != "TypeError: undefined is not a function" {
+		t.Errorf("Unexpected exception text: %q", exceptions[0].Text)
+	}
+
+	ew.Clear()
+	if ew.Count() != 0 {
+		t.Errorf("Expected count 0 after clear, got %d", ew.Count())
+	}
+}
+
+// TestAngularRouterState_Good verifies AngularRouterState struct.
+func TestAngularRouterState_Good(t *testing.T) {
+	state := AngularRouterState{
+		URL:      "/dashboard",
+		Fragment: "section1",
+		Params:   map[string]string{"id": "123"},
+		QueryParams: map[string]string{
+			"tab": "settings",
+		},
+	}
+
+	if state.URL != "/dashboard" {
+		t.Errorf("Expected URL '/dashboard', got %q", state.URL)
+	}
+	if state.Fragment != "section1" {
+		t.Errorf("Expected fragment 'section1', got %q", state.Fragment)
+	}
+	if state.Params["id"] != "123" {
+		t.Errorf("Expected param id '123', got %q", state.Params["id"])
+	}
+	if state.QueryParams["tab"] != "settings" {
+		t.Errorf("Expected query param tab 'settings', got %q", state.QueryParams["tab"])
+	}
+}
+
+// TestTargetInfo_Good verifies TargetInfo struct.
+func TestTargetInfo_Good(t *testing.T) {
+	target := TargetInfo{
+		ID:                   "ABC123",
+		Type:                 "page",
+		Title:                "Example",
+		URL:                  "https://example.com",
+		WebSocketDebuggerURL: "ws://localhost:9222/devtools/page/ABC123",
+	}
+
+	if target.ID != "ABC123" {
+		t.Errorf("Expected ID 'ABC123', got %q", target.ID)
+	}
+	if target.Type != "page" {
+		t.Errorf("Expected type 'page', got %q", target.Type)
+	}
+	if target.WebSocketDebuggerURL == "" {
+		t.Error("Expected WebSocketDebuggerURL to be set")
+	}
+}
+
+// TestConsoleWatcherAddMessage_Good verifies message buffer limit enforcement.
+func TestConsoleWatcherAddMessage_Good(t *testing.T) {
+	cw := &ConsoleWatcher{
+		messages: make([]ConsoleMessage, 0),
+		filters:  make([]ConsoleFilter, 0),
+		limit:    5,
+		handlers: make([]consoleHandlerRegistration, 0),
+	}
+
+	// Add messages past the limit
+	for i := range 7 {
+		cw.addMessage(ConsoleMessage{
+			Type: "log",
+			Text: time.Duration(i).String(),
+		})
+	}
+
+	if len(cw.messages) > cw.limit {
+		t.Errorf("Expected at most %d messages, got %d", cw.limit, len(cw.messages))
+	}
+}
+
+// TestConsoleWatcherHandler_Good verifies handlers are called for new messages.
+func TestConsoleWatcherHandler_Good(t *testing.T) {
+	cw := &ConsoleWatcher{
+		messages: make([]ConsoleMessage, 0),
+		filters:  make([]ConsoleFilter, 0),
+		limit:    1000,
+		handlers: make([]consoleHandlerRegistration, 0),
+	}
+
+	var received ConsoleMessage
+	cw.AddHandler(func(msg ConsoleMessage) {
+		received = msg
+	})
+
+	cw.addMessage(ConsoleMessage{Type: "error", Text: "handler test"})
+
+	if received.Text != "handler test" {
+		t.Errorf("Handler not called or wrong message: got %q", received.Text)
+	}
+}
+
+// TestConsoleWatcherFilteredMessages_Good verifies filtered message retrieval.
+func TestConsoleWatcherFilteredMessages_Good(t *testing.T) {
+	cw := &ConsoleWatcher{
+		messages: []ConsoleMessage{
+			{Type: "log", Text: "info msg"},
+			{Type: "error", Text: "error msg"},
+			{Type: "log", Text: "another info"},
+		},
+		filters:  []ConsoleFilter{{Type: "error"}},
+		limit:    1000,
+		handlers: make([]consoleHandlerRegistration, 0),
+	}
+
+	filtered := cw.FilteredMessages()
+	if len(filtered) != 1 {
+		t.Fatalf("Expected 1 filtered message, got %d", len(filtered))
+	}
+	if filtered[0].Type != "error" {
+		t.Errorf("Expected error type, got %q", filtered[0].Type)
+	}
+}
+
+// TestExceptionInfo_Good verifies ExceptionInfo struct.
+func TestExceptionInfo_Good(t *testing.T) {
+	info := ExceptionInfo{
+		Text:         "ReferenceError: foo is not defined",
+		LineNumber:   42,
+		ColumnNumber: 10,
+		URL:          "https://example.com/app.js",
+		StackTrace:   "  at bar (app.js:42:10)\n",
+		Timestamp:    time.Now(),
+	}
+
+	if info.Text != "ReferenceError: foo is not defined" {
+		t.Errorf("Unexpected text: %q", info.Text)
+	}
+	if info.LineNumber != 42 {
+		t.Errorf("Expected line 42, got %d", info.LineNumber)
+	}
+	if info.StackTrace == "" {
+		t.Error("Expected stack trace to be set")
+	}
+}