From 909fa86bea1f55acc1ccb119e9509d2c724f6b5b Mon Sep 17 00:00:00 2001
From: Peter Stone <thepeterstone@gmail.com>
Date: Thu, 26 Mar 2026 08:56:04 +0000
Subject: fix: ensure story branch exists before cloning at task start

Add ensureStoryBranch() that runs git ls-remote to check, then clones
into a temp dir to create and push the branch if missing. Called before
the task's own clone so checkout is guaranteed to succeed.

Removes the post-checkout fallback hack added in the previous commit.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 internal/executor/container_test.go | 79 +++++++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)

(limited to 'internal/executor/container_test.go')

diff --git a/internal/executor/container_test.go b/internal/executor/container_test.go
index 15c147f..f840f85 100644
--- a/internal/executor/container_test.go
+++ b/internal/executor/container_test.go
@@ -606,3 +606,82 @@ func TestContainerRunner_ClonesDefaultBranchWhenNoBranchName(t *testing.T) {
 		}
 	}
 }
+
+func TestEnsureStoryBranch_CreatesMissingBranch(t *testing.T) {
+	// Set up a bare repo and a local clone to test branch creation.
+	dir := t.TempDir()
+	bare := filepath.Join(dir, "bare.git")
+	local := filepath.Join(dir, "local")
+
+	// Create bare repo with an initial commit.
+	if out, err := exec.Command("git", "init", "--bare", bare).CombinedOutput(); err != nil {
+		t.Fatalf("git init bare: %v\n%s", err, out)
+	}
+	if out, err := exec.Command("git", "clone", bare, local).CombinedOutput(); err != nil {
+		t.Fatalf("git clone: %v\n%s", err, out)
+	}
+	if out, err := exec.Command("git", "-C", local, "commit", "--allow-empty", "-m", "init").CombinedOutput(); err != nil {
+		t.Fatalf("git commit: %v\n%s", err, out)
+	}
+	if out, err := exec.Command("git", "-C", local, "push", "origin", "main").CombinedOutput(); err != nil {
+		// try master
+		if out2, err2 := exec.Command("git", "-C", local, "push", "origin", "HEAD:main").CombinedOutput(); err2 != nil {
+			t.Fatalf("git push main: %v\n%s\n%s", err, out, out2)
+		}
+	}
+
+	runner := &ContainerRunner{Logger: slog.Default()}
+
+	branch := "story/test-branch"
+
+	// Branch should not exist yet.
+	out, _ := exec.Command("git", "ls-remote", "--heads", bare, branch).CombinedOutput()
+	if len(strings.TrimSpace(string(out))) > 0 {
+		t.Fatal("branch should not exist before ensureStoryBranch")
+	}
+
+	if err := runner.ensureStoryBranch(context.Background(), bare, branch, ""); err != nil {
+		t.Fatalf("ensureStoryBranch: %v", err)
+	}
+
+	// Branch should now exist in the bare repo.
+	out, err := exec.Command("git", "ls-remote", "--heads", bare, branch).CombinedOutput()
+	if err != nil || len(strings.TrimSpace(string(out))) == 0 {
+		t.Errorf("branch %q not found in bare repo after ensureStoryBranch: %s", branch, out)
+	}
+}
+
+func TestEnsureStoryBranch_IdempotentIfExists(t *testing.T) {
+	dir := t.TempDir()
+	bare := filepath.Join(dir, "bare.git")
+	local := filepath.Join(dir, "local")
+
+	if out, err := exec.Command("git", "init", "--bare", bare).CombinedOutput(); err != nil {
+		t.Fatalf("git init bare: %v\n%s", err, out)
+	}
+	if out, err := exec.Command("git", "clone", bare, local).CombinedOutput(); err != nil {
+		t.Fatalf("git clone: %v\n%s", err, out)
+	}
+	if out, err := exec.Command("git", "-C", local, "commit", "--allow-empty", "-m", "init").CombinedOutput(); err != nil {
+		t.Fatalf("git commit: %v\n%s", err, out)
+	}
+	if _, err := exec.Command("git", "-C", local, "push", "origin", "HEAD:main").CombinedOutput(); err != nil {
+		t.Fatalf("push main: %v", err)
+	}
+
+	branch := "story/existing-branch"
+	// Pre-create the branch.
+	if out, err := exec.Command("git", "-C", local, "checkout", "-b", branch).CombinedOutput(); err != nil {
+		t.Fatalf("checkout -b: %v\n%s", err, out)
+	}
+	if out, err := exec.Command("git", "-C", local, "push", "origin", branch).CombinedOutput(); err != nil {
+		t.Fatalf("push branch: %v\n%s", err, out)
+	}
+
+	runner := &ContainerRunner{Logger: slog.Default()}
+
+	// Should be a no-op, not an error.
+	if err := runner.ensureStoryBranch(context.Background(), bare, branch, ""); err != nil {
+		t.Fatalf("ensureStoryBranch on existing branch: %v", err)
+	}
+}
-- 
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