feat(html): allow locale in context constructors

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

context.go

@@ -20,18 +20,21 @@ type Context struct {
 }
 
 // NewContext creates a new rendering context with sensible defaults.
-// Usage example: html := Render(Text("welcome"), NewContext())
-func NewContext() *Context {
-	return &Context{
+// Usage example: html := Render(Text("welcome"), NewContext("en-GB"))
+func NewContext(locale ...string) *Context {
+	ctx := &Context{
 		Data: make(map[string]any),
 	}
+	if len(locale) > 0 {
+		ctx.Locale = locale[0]
+	}
+	return ctx
 }
 
 // NewContextWithService creates a rendering context backed by a specific translator.
-// Usage example: ctx := NewContextWithService(myTranslator)
-func NewContextWithService(svc Translator) *Context {
-	return &Context{
-		Data:    make(map[string]any),
-		service: svc,
-	}
+// Usage example: ctx := NewContextWithService(myTranslator, "en-GB")
+func NewContextWithService(svc Translator, locale ...string) *Context {
+	ctx := NewContext(locale...)
+	ctx.service = svc
+	return ctx
 }

context_test.go

@@ -0,0 +1,38 @@
+// SPDX-Licence-Identifier: EUPL-1.2
+
+package html
+
+import (
+	"testing"
+
+	i18n "dappco.re/go/core/i18n"
+)
+
+func TestNewContext_OptionalLocale_Good(t *testing.T) {
+	ctx := NewContext("en-GB")
+
+	if ctx == nil {
+		t.Fatal("NewContext returned nil")
+	}
+	if ctx.Locale != "en-GB" {
+		t.Fatalf("NewContext locale = %q, want %q", ctx.Locale, "en-GB")
+	}
+	if ctx.Data == nil {
+		t.Fatal("NewContext should initialise Data")
+	}
+}
+
+func TestNewContextWithService_OptionalLocale_Good(t *testing.T) {
+	svc, _ := i18n.New()
+	ctx := NewContextWithService(svc, "fr-FR")
+
+	if ctx == nil {
+		t.Fatal("NewContextWithService returned nil")
+	}
+	if ctx.Locale != "fr-FR" {
+		t.Fatalf("NewContextWithService locale = %q, want %q", ctx.Locale, "fr-FR")
+	}
+	if ctx.service == nil {
+		t.Fatal("NewContextWithService should set translator service")
+	}
+}