gittest: Disallow use of seeded repositories with SHA256

It's not currently possible to use our test repositories in combination
with SHA256 given that they're all using SHA1. This makes it easy to
accidentally test with SHA1 even though one thought to be testing with
SHA256.

Detect the use of seeded repositories and fail the test when done with
SHA256 is the default hash.

2 files changed, 13 insertions, 0 deletions

diff --git a/internal/git/gittest/objects.go b/internal/git/gittest/objects.go
index aafca61b2..62ef4733b 100644
--- a/internal/git/gittest/objects.go
+++ b/internal/git/gittest/objects.go
@@ -15,6 +15,11 @@ import (
 	"gitlab.com/gitlab-org/gitaly/v15/internal/helper/text"
 )
 
+// ObjectHashIsSHA256 returns if the current default object hash is SHA256.
+func ObjectHashIsSHA256() bool {
+	return DefaultObjectHash == git.ObjectHashSHA256
+}
+
 // RequireObjectExists asserts that the given repository does contain an object with the specified
 // object ID.
 func RequireObjectExists(t testing.TB, cfg config.Cfg, repoPath string, objectID git.ObjectID) {
diff --git a/internal/git/gittest/repo.go b/internal/git/gittest/repo.go
index 1b4b08bb3..201f459b1 100644
--- a/internal/git/gittest/repo.go
+++ b/internal/git/gittest/repo.go
@@ -144,6 +144,10 @@ func CreateRepository(ctx context.Context, t testing.TB, cfg config.Cfg, configs
 	}
 
 	if opts.Seed != "" {
+		if ObjectHashIsSHA256() {
+			require.FailNow(t, "seeded repository creation not supported with SHA256")
+		}
+
 		_, err := client.CreateRepositoryFromURL(ctx, &gitalypb.CreateRepositoryFromURLRequest{
 			Repository: repository,
 			Url:        testRepositoryPath(t, opts.Seed),
@@ -290,6 +294,10 @@ type CloneRepoOpts struct {
 // CloneRepo clones a new copy of test repository under a subdirectory in the storage root. You can
 // either pass no or exactly one CloneRepoOpts.
 func CloneRepo(t testing.TB, cfg config.Cfg, storage config.Storage, opts ...CloneRepoOpts) (*gitalypb.Repository, string) {
+	if ObjectHashIsSHA256() {
+		require.FailNow(t, "seeded repository creation not supported with SHA256")
+	}
+
 	require.Less(t, len(opts), 2, "you must either pass no or exactly one option")
 
 	opt := CloneRepoOpts{}