Enrich errors with error source using grpc status package

backend/data_adapter.go

@@ -4,6 +4,11 @@ import (
 	"context"
 	"errors"
 
+	"google.golang.org/genproto/googleapis/rpc/errdetails"
+	"google.golang.org/grpc/codes"
+	grpcstatus "google.golang.org/grpc/status"
+
+	"github.com/grafana/grafana-plugin-sdk-go/experimental/status"
 	"github.com/grafana/grafana-plugin-sdk-go/genproto/pluginv2"
 )
 
@@ -22,7 +27,7 @@ func (a *dataSDKAdapter) QueryData(ctx context.Context, req *pluginv2.QueryDataR
 	parsedReq := FromProto().QueryDataRequest(req)
 	resp, err := a.queryDataHandler.QueryData(ctx, parsedReq)
 	if err != nil {
-		return nil, err
+		return nil, enrichWithErrorSourceInfo(err)
 	}
 
 	if resp == nil {
@@ -31,3 +36,30 @@ func (a *dataSDKAdapter) QueryData(ctx context.Context, req *pluginv2.QueryDataR
 
 	return ToProto().QueryDataResponse(resp)
 }
+
+// enrichWithErrorSourceInfo returns a gRPC status error with error source info as metadata.
+func enrichWithErrorSourceInfo(err error) error {
+	var errorSource status.Source
+	if IsDownstreamError(err) {
+		errorSource = status.SourceDownstream
+	} else if IsPluginError(err) {
+		errorSource = status.SourcePlugin
+	}
+
+	// Unless the error is explicitly marked as a plugin or downstream error, we don't enrich it.
+	if errorSource == "" {
+		return err
+	}
+
+	status := grpcstatus.New(codes.Unknown, err.Error())
+	status, innerErr := status.WithDetails(&errdetails.ErrorInfo{
+		Metadata: map[string]string{
+			"errorSource": errorSource.String(),
+		},
+	})
+	if innerErr != nil {
+		return err
+	}
+
+	return status.Err()
+}

backend/data_adapter_test.go

@@ -3,14 +3,17 @@ package backend
 import (
 	"bytes"
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
 	"net/http/httptest"
 	"testing"
 
 	"github.com/stretchr/testify/require"
+	"google.golang.org/genproto/googleapis/rpc/errdetails"
 	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
 
 	"github.com/grafana/grafana-plugin-sdk-go/backend/httpclient"
 	"github.com/grafana/grafana-plugin-sdk-go/genproto/pluginv2"
@@ -147,6 +150,75 @@ func TestQueryData(t *testing.T) {
 		})
 		require.NoError(t, err)
 	})
+
+	t.Run("Error source error from QueryData handler will be enriched with grpc status", func(t *testing.T) {
+		t.Run("When error is a downstream error", func(t *testing.T) {
+			adapter := newDataSDKAdapter(QueryDataHandlerFunc(
+				func(_ context.Context, _ *QueryDataRequest) (*QueryDataResponse, error) {
+					return nil, DownstreamError(errors.New("oh no"))
+				},
+			))
+
+			_, err := adapter.QueryData(context.Background(), &pluginv2.QueryDataRequest{
+				PluginContext: &pluginv2.PluginContext{},
+			})
+			require.Error(t, err)
+
+			st := status.Convert(err)
+			require.NotNil(t, st)
+			require.NotEmpty(t, st.Details())
+			for _, detail := range st.Details() {
+				errorInfo, ok := detail.(*errdetails.ErrorInfo)
+				require.True(t, ok)
+				require.NotNil(t, errorInfo)
+				errorSource, exists := errorInfo.Metadata["errorSource"]
+				require.True(t, exists)
+				require.Equal(t, ErrorSourceDownstream.String(), errorSource)
+			}
+		})
+
+		t.Run("When error is a plugin error", func(t *testing.T) {
+			adapter := newDataSDKAdapter(QueryDataHandlerFunc(
+				func(_ context.Context, _ *QueryDataRequest) (*QueryDataResponse, error) {
+					return nil, PluginError(errors.New("oh no"))
+				},
+			))
+
+			_, err := adapter.QueryData(context.Background(), &pluginv2.QueryDataRequest{
+				PluginContext: &pluginv2.PluginContext{},
+			})
+			require.Error(t, err)
+
+			st := status.Convert(err)
+			require.NotNil(t, st)
+			require.NotEmpty(t, st.Details())
+			for _, detail := range st.Details() {
+				errorInfo, ok := detail.(*errdetails.ErrorInfo)
+				require.True(t, ok)
+				require.NotNil(t, errorInfo)
+				errorSource, exists := errorInfo.Metadata["errorSource"]
+				require.True(t, exists)
+				require.Equal(t, ErrorSourcePlugin.String(), errorSource)
+			}
+		})
+
+		t.Run("When error is neither a downstream or plugin error", func(t *testing.T) {
+			adapter := newDataSDKAdapter(QueryDataHandlerFunc(
+				func(_ context.Context, _ *QueryDataRequest) (*QueryDataResponse, error) {
+					return nil, errors.New("oh no")
+				},
+			))
+
+			_, err := adapter.QueryData(context.Background(), &pluginv2.QueryDataRequest{
+				PluginContext: &pluginv2.PluginContext{},
+			})
+			require.Error(t, err)
+
+			st := status.Convert(err)
+			require.NotNil(t, st)
+			require.Empty(t, st.Details())
+		})
+	})
 }
 
 var finalRoundTripper = httpclient.RoundTripperFunc(func(req *http.Request) (*http.Response, error) {

backend/error_source.go

@@ -32,6 +32,10 @@ func ErrorSourceFromHTTPStatus(statusCode int) ErrorSource {
 	return status.SourceFromHTTPStatus(statusCode)
 }
 
+func IsPluginError(err error) bool {
+	return status.IsPluginError(err)
+}
+
 // IsDownstreamError return true if provided error is an error with downstream source or
 // a timeout error or a cancelled error.
 func IsDownstreamError(err error) bool {

experimental/status/status_source.go

@@ -114,6 +114,13 @@ func (e ErrorWithSource) Unwrap() error {
 	return e.err
 }
 
+func IsPluginError(err error) bool {
+	e := ErrorWithSource{
+		source: SourcePlugin,
+	}
+	return errors.Is(err, e)
+}
+
 // IsDownstreamError return true if provided error is an error with downstream source or
 // a timeout error or a cancelled error.
 func IsDownstreamError(err error) bool {

experimental/status/status_source_test.go

@@ -106,6 +106,47 @@ func TestIsDownstreamError(t *testing.T) {
 	}
 }
 
+func TestIsPluginError(t *testing.T) {
+	tcs := []struct {
+		name     string
+		err      error
+		expected bool
+	}{
+		{
+			name:     "nil",
+			err:      nil,
+			expected: false,
+		},
+		{
+			name:     "plugin error",
+			err:      backend.NewErrorWithSource(nil, backend.ErrorSourcePlugin),
+			expected: true,
+		},
+		{
+			name:     "downstream error",
+			err:      backend.NewErrorWithSource(nil, backend.ErrorSourceDownstream),
+			expected: false,
+		},
+		{
+			name:     "other error",
+			err:      fmt.Errorf("other error"),
+			expected: false,
+		},
+		{
+			name:     "network error",
+			err:      newFakeNetworkError(true, true),
+			expected: false,
+		},
+	}
+	for _, tc := range tcs {
+		t.Run(tc.name, func(t *testing.T) {
+			wrappedErr := fmt.Errorf("error: %w", tc.err)
+			assert.Equalf(t, tc.expected, status.IsPluginError(tc.err), "IsPluginError(%v)", tc.err)
+			assert.Equalf(t, tc.expected, status.IsPluginError(wrappedErr), "wrapped IsPluginError(%v)", wrappedErr)
+		})
+	}
+}
+
 func TestIsDownstreamHTTPError(t *testing.T) {
 	tcs := []struct {
 		name       string