From dbd57451f169b0b76f71ca9c34c52f447aa0ff3b Mon Sep 17 00:00:00 2001
From: Runxi Yu
Date: Sat, 6 Jun 2026 18:31:42 +0000
Subject: internal/testgit: Maybe SHA-256 repos by default

---
 internal/testgit/repo.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/internal/testgit/repo.go b/internal/testgit/repo.go
index fa89c022..940ba1e1 100644
--- a/internal/testgit/repo.go
+++ b/internal/testgit/repo.go
@@ -20,9 +20,14 @@ type RepoOptions struct {
 func NewRepo(tb testing.TB, opts RepoOptions) (*Repo, error) {
 	tb.Helper()
 
+	objectFormat := opts.ObjectFormat
+	if objectFormat == id.ObjectFormatUnknown {
+		objectFormat = id.ObjectFormatSHA256
+	}
+
 	repo := &Repo{
 		path:         tb.TempDir(),
-		objectFormat: opts.ObjectFormat,
+		objectFormat: objectFormat,
 		env: append(os.Environ(),
 			"GIT_CONFIG_GLOBAL=/dev/null",
 			"GIT_CONFIG_SYSTEM=/dev/null",
-- 
cgit v1.3.1-10-gc9f91