Implement resourceInUse error for dataset deletion

internal/metadata/project.go

@@ -9,6 +9,7 @@ import (
 )
 
 var ErrDuplicatedDataset = errors.New("dataset is already created")
+var ErrDatasetInUse = errors.New("dataset is in use, empty the dataset before deleting it")
 
 type Project struct {
 	ID         string
@@ -92,6 +93,9 @@ func (p *Project) DeleteDataset(ctx context.Context, tx *sql.Tx, id string) erro
 	if !exists {
 		return fmt.Errorf("dataset '%s' is not found in project '%s'", id, p.ID)
 	}
+	if len(dataset.TableIDs()) > 0 {
+		return fmt.Errorf("dataset %s: %w", id, ErrDatasetInUse)
+	}
 	if err := dataset.Delete(ctx, tx); err != nil {
 		return err
 	}

server/handler.go

@@ -592,6 +592,11 @@ func (h *datasetsDeleteHandler) ServeHTTP(w http.ResponseWriter, r *http.Request
 		dataset:        dataset,
 		deleteContents: isDeleteContents(r),
 	}); err != nil {
+		if errors.Is(err, metadata.ErrDatasetInUse) {
+			errorResponse(ctx, w, errResourceInUse(err.Error()))
+			return
+		}
+
 		errorResponse(ctx, w, errInternalError(err.Error()))
 		return
 	}

server/server_test.go

@@ -30,14 +30,30 @@ import (
 	"google.golang.org/api/option"
 )
 
+func buildClient(ctx context.Context, project *types.Project, server *server.TestServer) (*bigquery.Client, error) {
+	client, err := bigquery.NewClient(
+		ctx,
+		project.ID,
+		option.WithEndpoint(server.URL),
+		option.WithoutAuthentication(),
+	)
+
+	if err != nil {
+		return nil, err
+	}
+	return client, nil
+
+}
+
 func TestSimpleQuery(t *testing.T) {
 	ctx := context.Background()
 
 	bqServer, err := server.New(server.TempStorage)
 	if err != nil {
 		t.Fatal(err)
 	}
-	if err := bqServer.Load(server.StructSource(types.NewProject("test"))); err != nil {
+	project := types.NewProject("test")
+	if err := bqServer.Load(server.StructSource()); err != nil {
 		t.Fatal(err)
 	}
 	testServer := bqServer.TestServer()
@@ -46,12 +62,7 @@ func TestSimpleQuery(t *testing.T) {
 		bqServer.Stop(ctx)
 	}()
 
-	client, err := bigquery.NewClient(
-		ctx,
-		"test",
-		option.WithEndpoint(testServer.URL),
-		option.WithoutAuthentication(),
-	)
+	client, err := buildClient(ctx, project, testServer)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -893,6 +904,47 @@ func TestDuplicateDataset(t *testing.T) {
 	}
 }
 
+func TestDeleteDatasetInUseJob(t *testing.T) {
+	const (
+		projectName = "test"
+		datasetName = "dataset1"
+	)
+	ctx := context.Background()
+
+	bqServer, err := server.New(server.TempStorage)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	project := types.NewProject(projectName, types.NewDataset(datasetName,
+		types.NewTable("table1", []*types.Column{
+			types.NewColumn("id", types.STRING),
+		}, nil),
+	))
+
+	if err := bqServer.Load(server.StructSource(project)); err != nil {
+		t.Fatal(err)
+	}
+
+	testServer := bqServer.TestServer()
+	defer func() {
+		testServer.Close()
+		bqServer.Stop(ctx)
+	}()
+
+	client, err := buildClient(ctx, project, testServer)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer client.Close()
+
+	dataset := client.Dataset(datasetName)
+	err = dataset.Delete(ctx)
+	if err == nil || !strings.HasSuffix(err.Error(), "resourceInUse") {
+		t.Fatalf("expected resource in use error; got %s", err)
+	}
+}
+
 func TestDataFromStruct(t *testing.T) {
 	ctx := context.Background()