ref service: Implement HeadOnly option for FindDefaultBranchNameuse_head_reference

2 files changed, 60 insertions, 4 deletions

diff --git a/internal/gitaly/service/ref/refs.go b/internal/gitaly/service/ref/refs.go
index b1c9b5c79..5627a0073 100644
--- a/internal/gitaly/service/ref/refs.go
+++ b/internal/gitaly/service/ref/refs.go
@@ -76,11 +76,18 @@ func (s *server) FindDefaultBranchName(ctx context.Context, in *gitalypb.FindDef
 	}
 	repo := s.localrepo(repository)
 
+	if in.GetHeadOnly() {
+		head, err := repo.HeadReference(ctx)
+		if err != nil {
+			return nil, structerr.NewInternal("head reference: %w", err)
+		}
+		return &gitalypb.FindDefaultBranchNameResponse{Name: []byte(head)}, nil
+	}
+
 	defaultBranch, err := repo.GetDefaultBranch(ctx)
 	if err != nil {
-		return nil, structerr.NewInternal("%w", err)
+		return nil, structerr.NewInternal("get default branch: %w", err)
 	}
-
 	return &gitalypb.FindDefaultBranchNameResponse{Name: []byte(defaultBranch)}, nil
 }
 
diff --git a/internal/gitaly/service/ref/refs_test.go b/internal/gitaly/service/ref/refs_test.go
index 3af702173..557d12820 100644
--- a/internal/gitaly/service/ref/refs_test.go
+++ b/internal/gitaly/service/ref/refs_test.go
@@ -53,6 +53,25 @@ func TestFindDefaultBranchName(t *testing.T) {
 			expectedName: git.DefaultRef,
 		},
 		{
+			desc: "successful, HEAD only",
+			setup: func(t *testing.T, ctx context.Context, cfg config.Cfg) setupData {
+				repo, repoPath := gittest.CreateRepository(t, ctx, cfg)
+
+				oid := gittest.WriteCommit(t, cfg, repoPath, gittest.WithReference(git.DefaultRef.String()))
+				gittest.WriteCommit(t, cfg, repoPath, gittest.WithReference(git.LegacyDefaultRef.String()), gittest.WithParents(oid))
+				gittest.WriteCommit(t, cfg, repoPath, gittest.WithBranch("apple"), gittest.WithParents(oid))
+				gittest.WriteCommit(t, cfg, repoPath, gittest.WithBranch("banana"), gittest.WithParents(oid))
+
+				return setupData{
+					request: &gitalypb.FindDefaultBranchNameRequest{
+						Repository: repo,
+						HeadOnly:   true,
+					},
+				}
+			},
+			expectedName: git.DefaultRef,
+		},
+		{
 			desc: "successful, single branch",
 			setup: func(t *testing.T, ctx context.Context, cfg config.Cfg) setupData {
 				repo, repoPath := gittest.CreateRepository(t, ctx, cfg)
@@ -68,6 +87,22 @@ func TestFindDefaultBranchName(t *testing.T) {
 			expectedName: "refs/heads/banana",
 		},
 		{
+			desc: "successful, single branch, HEAD only",
+			setup: func(t *testing.T, ctx context.Context, cfg config.Cfg) setupData {
+				repo, repoPath := gittest.CreateRepository(t, ctx, cfg)
+
+				gittest.WriteCommit(t, cfg, repoPath, gittest.WithBranch("banana"))
+
+				return setupData{
+					request: &gitalypb.FindDefaultBranchNameRequest{
+						Repository: repo,
+						HeadOnly:   true,
+					},
+				}
+			},
+			expectedName: git.DefaultRef,
+		},
+		{
 			desc: "successful, updated default",
 			setup: func(t *testing.T, ctx context.Context, cfg config.Cfg) setupData {
 				repo, repoPath := gittest.CreateRepository(t, ctx, cfg)
@@ -99,6 +134,20 @@ func TestFindDefaultBranchName(t *testing.T) {
 			},
 		},
 		{
+			desc: "empty repository, HEAD only",
+			setup: func(t *testing.T, ctx context.Context, cfg config.Cfg) setupData {
+				repo, _ := gittest.CreateRepository(t, ctx, cfg)
+
+				return setupData{
+					request: &gitalypb.FindDefaultBranchNameRequest{
+						Repository: repo,
+						HeadOnly:   true,
+					},
+				}
+			},
+			expectedName: git.DefaultRef,
+		},
+		{
 			desc: "repository not provided",
 			setup: func(t *testing.T, ctx context.Context, cfg config.Cfg) setupData {
 				return setupData{
@@ -118,7 +167,7 @@ func TestFindDefaultBranchName(t *testing.T) {
 						Repository: &gitalypb.Repository{StorageName: cfg.Storages[0].Name, RelativePath: "made/up/path"},
 					},
 					expectedErr: status.Error(codes.NotFound, testhelper.GitalyOrPraefect(
-						`GetRepoPath: not a git repository: "`+cfg.Storages[0].Path+`/made/up/path"`,
+						`get default branch: GetRepoPath: not a git repository: "`+cfg.Storages[0].Path+`/made/up/path"`,
 						`accessor call: route repository accessor: consistent storages: repository "default"/"made/up/path" not found`,
 					)),
 				}
@@ -134,7 +183,7 @@ func TestFindDefaultBranchName(t *testing.T) {
 						Repository: &gitalypb.Repository{StorageName: "invalid", RelativePath: repo.GetRelativePath()},
 					},
 					expectedErr: status.Error(codes.InvalidArgument, testhelper.GitalyOrPraefect(
-						`GetStorageByName: no such storage: "invalid"`,
+						`get default branch: GetStorageByName: no such storage: "invalid"`,
 						"repo scoped: invalid Repository",
 					)),
 				}