1 files changed, 80 insertions, 0 deletions
diff --git a/workhorse/internal/git/error_test.go b/workhorse/internal/git/error_test.go
new file mode 100644
index 00000000000..d87c81fc83c
--- /dev/null
+++ b/workhorse/internal/git/error_test.go
@@ -0,0 +1,80 @@
+package git
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"gitlab.com/gitlab-org/gitaly/v14/proto/go/gitalypb"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/types/known/anypb"
+	"google.golang.org/protobuf/types/known/durationpb"
+)
+
+func TestHandleLimitErr(t *testing.T) {
+	testCases := []struct {
+		desc          string
+		errWriter     func(io.Writer) error
+		expectedBytes []byte
+	}{
+		{
+			desc:      "upload pack",
+			errWriter: writeUploadPackError,
+			expectedBytes: bytes.Join([][]byte{
+				[]byte{'0', '0', '4', '7'},
+				[]byte("ERR GitLab is currently unable to handle this request due to load.\n"),
+			}, []byte{}),
+		},
+		{
+			desc:      "recieve pack",
+			errWriter: writeReceivePackError,
+			expectedBytes: bytes.Join([][]byte{
+				{'0', '0', '2', '3', 1, '0', '0', '1', 'a'},
+				[]byte("unpack server is busy\n"),
+				{'0', '0', '0', '0', '0', '0', '4', '4', 2},
+				[]byte("GitLab is currently unable to handle this request due to load.\n"),
+				{'0', '0', '0', '0'},
+			}, []byte{}),
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.desc, func(t *testing.T) {
+			var body bytes.Buffer
+			err := errWithDetail(t, &gitalypb.LimitError{
+				ErrorMessage: "concurrency queue wait time reached",
+				RetryAfter:   durationpb.New(0)})
+
+			handleLimitErr(fmt.Errorf("wrapped error: %w", err), &body, tc.errWriter)
+			require.Equal(t, tc.expectedBytes, body.Bytes())
+		})
+	}
+
+	t.Run("non LimitError", func(t *testing.T) {
+		var body bytes.Buffer
+		err := status.Error(codes.Internal, "some internal error")
+		handleLimitErr(fmt.Errorf("wrapped error: %w", err), &body, writeUploadPackError)
+		require.Equal(t, []byte(nil), body.Bytes())
+
+		handleLimitErr(fmt.Errorf("wrapped error: %w", err), &body, writeReceivePackError)
+		require.Equal(t, []byte(nil), body.Bytes())
+
+	})
+}
+
+// errWithDetail adds the given details to the error if it is a gRPC status whose code is not OK.
+func errWithDetail(t *testing.T, detail proto.Message) error {
+	st := status.New(codes.Unavailable, "too busy")
+
+	proto := st.Proto()
+	marshaled, err := anypb.New(detail)
+	require.NoError(t, err)
+
+	proto.Details = append(proto.Details, marshaled)
+
+	return status.ErrorProto(proto)
+}