chore: allow empty run metadata requests to delete existing metadata (#…

…9524)

master/internal/api_runs.go

@@ -943,10 +943,6 @@ func (a *apiServer) PostRunMetadata(
 		return nil, err
 	}
 
-	if len(req.Metadata.AsMap()) == 0 || req.Metadata.AsMap() == nil {
-		return nil, status.Error(codes.InvalidArgument, "metadata cannot be empty")
-	}
-
 	// Flatten Request Metadata.
 	flatMetadata, err := run.FlattenMetadata(req.Metadata.AsMap())
 	if err != nil {

master/internal/api_runs_intg_test.go

@@ -1247,6 +1247,22 @@ func TestPostRunMetadata(t *testing.T) {
 	})
 	require.NoError(t, err)
 	require.Equal(t, rawMetadata, metadataResp.Metadata.AsMap())
+
+	// empty metadata
+	metadataResp, err = api.PostRunMetadata(ctx, &apiv1.PostRunMetadataRequest{
+		RunId:    r.Id,
+		Metadata: &structpb.Struct{},
+	})
+	require.NoError(t, err)
+	require.Empty(t, metadataResp.Metadata.AsMap())
+
+	// nil metadata
+	metadataResp, err = api.PostRunMetadata(ctx, &apiv1.PostRunMetadataRequest{
+		RunId:    r.Id,
+		Metadata: nil,
+	})
+	require.NoError(t, err)
+	require.Empty(t, metadataResp.Metadata.AsMap())
 }
 
 func TestRunMetadata(t *testing.T) {

master/internal/db/postgres_runs.go

@@ -59,6 +59,11 @@ func UpdateRunMetadata(
 			if err != nil {
 				return fmt.Errorf("deleting run metadata indexes for run(%d): %w", runID, err)
 			}
+
+			// ignore if there is no metadata to insert.
+			if len(flatMetadata) == 0 {
+				return nil
+			}
 			_, err = tx.NewInsert().Model(&flatMetadata).Exec(ctx)
 			if err != nil {
 				return fmt.Errorf("inserting run metadata indexes for run(%d): %w", runID, err)

master/internal/run/runs.go

@@ -30,7 +30,7 @@ func FlattenMetadata(
 	data map[string]any,
 ) (flatMetadata []model.RunMetadataIndex, err error) {
 	if len(data) == 0 {
-		return nil, fmt.Errorf("metadata is empty")
+		return nil, nil
 	}
 	flatMetadata, err = flattenMetadata(data)
 	if err != nil {

master/internal/run/runs_test.go

@@ -91,15 +91,15 @@ func TestFlattenMetadata(t *testing.T) {
 
 func TestFlattenMetadataEmpty(t *testing.T) {
 	data := map[string]interface{}{}
-	_, err := FlattenMetadata(data)
-	require.Error(t, err, "metadata is empty")
+	flatMetadata, err := FlattenMetadata(data)
+	require.NoError(t, err)
+	require.Empty(t, flatMetadata)
 }
 
-// TODO(corban): this should actually be adjusted to return an error since we don't want to
-// allow empty post requests to be made to the metadata endpoint.
 func TestFlattenMetadataNil(t *testing.T) {
-	_, err := FlattenMetadata(nil)
-	require.Error(t, err, "metadata is empty")
+	flatMetadata, err := FlattenMetadata(nil)
+	require.NoError(t, err)
+	require.Empty(t, flatMetadata)
 }
 
 func TestFlattenMetadataNested(t *testing.T) {