feat(api): allow openapi specs from readers

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

client.go

@@ -29,6 +29,7 @@ import (
 //	data, err := client.Call("get_health", nil)
 type OpenAPIClient struct {
 	specPath    string
+	specReader  io.Reader
 	baseURL     string
 	bearerToken string
 	httpClient  *http.Client
@@ -67,6 +68,18 @@ func WithSpec(path string) OpenAPIClientOption {
 	}
 }
 
+// WithSpecReader sets an in-memory or streamed OpenAPI document source.
+// It is read once the first time the client loads its spec.
+//
+// Example:
+//
+//	client := api.NewOpenAPIClient(api.WithSpecReader(strings.NewReader(spec)))
+func WithSpecReader(reader io.Reader) OpenAPIClientOption {
+	return func(c *OpenAPIClient) {
+		c.specReader = reader
+	}
+}
+
 // WithBaseURL sets the base URL used for outgoing requests.
 //
 // Example:
@@ -239,17 +252,25 @@ func (c *OpenAPIClient) load() error {
 }
 
 func (c *OpenAPIClient) loadSpec() error {
-	if c.specPath == "" {
-		return coreerr.E("OpenAPIClient.loadSpec", "spec path is required", nil)
+	var (
+		data []byte
+		err  error
+	)
+
+	switch {
+	case c.specReader != nil:
+		data, err = io.ReadAll(c.specReader)
+	case c.specPath != "":
+		f, openErr := os.Open(c.specPath)
+		if openErr != nil {
+			return coreerr.E("OpenAPIClient.loadSpec", "read spec", openErr)
+		}
+		defer f.Close()
+		data, err = io.ReadAll(f)
+	default:
+		return coreerr.E("OpenAPIClient.loadSpec", "spec path or reader is required", nil)
 	}
 
-	f, err := os.Open(c.specPath)
-	if err != nil {
-		return coreerr.E("OpenAPIClient.loadSpec", "read spec", err)
-	}
-	defer f.Close()
-
-	data, err := io.ReadAll(f)
 	if err != nil {
 		return coreerr.E("OpenAPIClient.loadSpec", "read spec", err)
 	}

client_test.go

@@ -9,6 +9,7 @@ import (
 	"net/http/httptest"
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
 
 	api "dappco.re/go/core/api"
@@ -125,6 +126,54 @@ paths:
 	}
 }
 
+func TestOpenAPIClient_Good_LoadsSpecFromReader(t *testing.T) {
+	errCh := make(chan error, 1)
+	mux := http.NewServeMux()
+	mux.HandleFunc("/ping", func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodGet {
+			errCh <- fmt.Errorf("expected GET, got %s", r.Method)
+			w.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`{"success":true,"data":{"message":"pong"}}`))
+	})
+
+	srv := httptest.NewServer(mux)
+	defer srv.Close()
+
+	client := api.NewOpenAPIClient(
+		api.WithSpecReader(strings.NewReader(`openapi: 3.1.0
+info:
+  title: Test API
+  version: 1.0.0
+paths:
+  /ping:
+    get:
+      operationId: ping
+`)),
+		api.WithBaseURL(srv.URL),
+	)
+
+	result, err := client.Call("ping", nil)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	select {
+	case err := <-errCh:
+		t.Fatal(err)
+	default:
+	}
+
+	ping, ok := result.(map[string]any)
+	if !ok {
+		t.Fatalf("expected map result, got %T", result)
+	}
+	if ping["message"] != "pong" {
+		t.Fatalf("expected message=pong, got %#v", ping["message"])
+	}
+}
+
 func TestOpenAPIClient_Good_CallHeadOperationWithRequestBody(t *testing.T) {
 	errCh := make(chan error, 1)
 	mux := http.NewServeMux()