fix EventReceiver does not propagate request context

v2/client/http_receiver.go

@@ -29,7 +29,7 @@ func (r *EventReceiver) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 		r.p.ServeHTTP(rw, req)
 	}()
 
-	ctx := context.Background()
+	ctx := req.Context()
 	msg, respFn, err := r.p.Respond(ctx)
 	if err != nil {
 		//lint:ignore SA9003 TODO: Branch left empty

v2/client/http_receiver_test.go

@@ -0,0 +1,66 @@
+package client_test
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	cloudevents "github.com/cloudevents/sdk-go/v2"
+	"github.com/cloudevents/sdk-go/v2/client"
+	"github.com/stretchr/testify/require"
+)
+
+func TestEventReceiverServeHTTP_WithContext(t *testing.T) {
+	type ctxKey string
+	const ctxKeyTest ctxKey = "testKey"
+
+	middleware := func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			ctx := r.Context()
+			ctx = context.WithValue(ctx, ctxKeyTest, "testValue")
+			next.ServeHTTP(w, r.WithContext(ctx))
+		})
+	}
+
+	eventReceiver := func(ctx context.Context) error {
+		v, ok := ctx.Value(ctxKeyTest).(string)
+		if !ok {
+			t.Errorf("invalid context value type: %v", v)
+			return errors.New("invalid context")
+		}
+		if v != "testValue" {
+			t.Errorf("invalid context value: %s", v)
+			return errors.New("invalid context")
+		}
+		return nil
+	}
+
+	p, err := cloudevents.NewHTTP()
+	if err != nil {
+		t.Fatal(err)
+	}
+	httpHandler, err := client.NewHTTPReceiveHandler(context.Background(), p, eventReceiver)
+	if err != nil {
+		t.Fatal(err)
+	}
+	c, err := cloudevents.NewDefaultClient()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	mux := http.NewServeMux()
+	mux.Handle("/test", middleware(httpHandler))
+	ts := httptest.NewServer(mux)
+	t.Cleanup(ts.Close)
+
+	event := cloudevents.NewEvent()
+	event.SetSource("testSource")
+	event.SetType("testType")
+	ctx := context.Background()
+	ctx = cloudevents.ContextWithTarget(ctx, ts.URL+"/test")
+
+	result := c.Send(ctx, event)
+	require.True(t, cloudevents.IsACK(result))
+}