Complete forge delivery regression coverage

internal/gitea/backend_test.go

@@ -400,10 +400,56 @@ func TestBackendUploadAssetPreservesCancellationAsUncertain(t *testing.T) {
 	}
 }
 
+func TestBackendUploadAssetWaitsForMultipartWriterAfterReaderFailure(t *testing.T) {
+	readerErr := errors.New("asset reader failed")
+	readDone := make(chan struct{})
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method == http.MethodGet && r.URL.Path == "/api/v1/repos/owner/project/releases/tags/v1.2.3" {
+			_ = json.NewEncoder(w).Encode(releaseResponse{ID: 10, TagName: "v1.2.3"})
+			return
+		}
+		_, _ = io.Copy(io.Discard, r.Body)
+		_ = json.NewEncoder(w).Encode(assetResponse{ID: 50, Name: "app.bin", Size: 0})
+	}))
+	defer server.Close()
+	backend := NewBackend(testDestination(server.URL), server.Client())
+	release, err := backend.FindRelease(context.Background(), "v1.2.3")
+	if err != nil {
+		t.Fatalf("FindRelease() error = %v", err)
+	}
+
+	evidence, err := backend.UploadAsset(context.Background(), release.Handle, "app.bin", failingUploadReader{err: readerErr, done: readDone})
+	select {
+	case <-readDone:
+	default:
+		t.Fatal("UploadAsset() returned before the multipart worker finished reading")
+	}
+	if !errors.Is(err, readerErr) {
+		t.Fatalf("UploadAsset() error = %v, want reader cause %v", err, readerErr)
+	}
+	if !evidence.Attempted || evidence.Disposition != forge.WriteUncertain {
+		t.Fatalf("UploadAsset() evidence = %#v, want uncertain attempted write", evidence)
+	}
+}
+
+type failingUploadReader struct {
+	err  error
+	done chan struct{}
+}
+
+func (reader failingUploadReader) Read([]byte) (int, error) {
+	close(reader.done)
+	return 0, reader.err
+}
+
 func validCreateReleaseRequest() forge.CreateReleaseRequest {
 	return forge.CreateReleaseRequest{Tag: "v1.2.3", Commit: strings.Repeat("a", 40), Title: "Release", Body: "# Release"}
 }
 
+func testDestination(baseURL string) Destination {
+	return Destination{BaseURL: baseURL, Owner: "owner", Repository: "project", Token: "fixture-secret-token"}
+}
+
 type trackedReader struct {
 	io.Reader
 	closed bool