DEVX-49: fix: remove auto-rebase from auto-merge to prevent CI feedback loop

tests/unit/test_auto_merge.py

@@ -253,31 +253,34 @@ class TestMain:
     @patch.dict("os.environ", {"REPO_TOKEN": "tok", "VIKUNJA_TOKEN": "tok"}, clear=True)
     @patch("devx.ci.auto_merge.validate_pr_title_matches_vikunja")
     @patch("devx.ci.auto_merge.GiteaClient")
-    def test_merge_behind_master_rebases(
+    def test_merge_behind_master_raises_no_rebase(
         self, mock_client_cls: MagicMock, _mock_validate: MagicMock, tmp_path, monkeypatch
     ) -> None:  # type: ignore[no-untyped-def]
+        """When branch is behind master, auto-merge should NOT rebase.
+
+        Auto-rebasing creates a feedback loop: the force-push triggers a new
+        pull_request synchronize event, which starts a new CI run, which runs
+        auto-merge again, which rebases again, etc.
+        """
         monkeypatch.chdir(tmp_path)
 
         mock_client = MagicMock()
         mock_client.get_pr_commits.return_value = [
             {"commit": {"message": "fix: resolve timeout"}},
         ]
-        mock_client.merge_pr.side_effect = [
-            APIError(405, "HEAD branch is behind master"),
-            None,  # Second call succeeds
-        ]
+        mock_client.merge_pr.side_effect = APIError(405, "HEAD branch is behind master")
         mock_client_cls.return_value = mock_client
 
-        with patch("devx.ci.auto_merge.run_cmd") as mock_run:
-            runner = CliRunner()
-            result = runner.invoke(
-                main,
-                ["DEVX-19-fix-bug", "DEVX-19: Fix timeout", "owner/repo", "7"],
-            )
-            assert result.exit_code == 0, result.output
-            assert mock_client.merge_pr.call_count == 2
-            # Should have fetched, rebased, and pushed
-            assert mock_run.call_count == 5  # config name, config email, fetch, rebase, push
+        runner = CliRunner()
+        result = runner.invoke(
+            main,
+            ["DEVX-19-fix-bug", "DEVX-19: Fix timeout", "owner/repo", "7"],
+        )
+        assert result.exit_code != 0
+        assert "behind master" in result.output.lower()
+        assert "rebase manually" in result.output.lower()
+        # Must NOT have called merge_pr twice (no retry after rebase)
+        assert mock_client.merge_pr.call_count == 1
 
     @patch.dict("os.environ", {"REPO_TOKEN": "tok", "VIKUNJA_TOKEN": "tok"}, clear=True)
     @patch("devx.ci.auto_merge.validate_pr_title_matches_vikunja")
@@ -344,10 +347,10 @@ class TestMain:
     @patch.dict("os.environ", {"REPO_TOKEN": "tok", "VIKUNJA_TOKEN": "tok"}, clear=True)
     @patch("devx.ci.auto_merge.validate_pr_title_matches_vikunja")
     @patch("devx.ci.auto_merge.GiteaClient")
-    def test_rebase_retry_failure_raises(
+    def test_merge_behind_master_does_not_force_push(
         self, mock_client_cls: MagicMock, _mock_validate: MagicMock, tmp_path, monkeypatch
     ) -> None:  # type: ignore[no-untyped-def]
-        """When rebase retry also fails, raises with helpful message."""
+        """Verify no git commands are run when branch is behind master."""
         monkeypatch.chdir(tmp_path)
 
         mock_client = MagicMock()
@@ -358,14 +361,14 @@ class TestMain:
         mock_client_cls.return_value = mock_client
 
         with patch("devx.ci.auto_merge.run_cmd") as mock_run:
-            mock_run.side_effect = click.ClickException("git rebase failed")
             runner = CliRunner()
             result = runner.invoke(
                 main,
                 ["DEVX-19-fix-bug", "DEVX-19: Fix timeout", "owner/repo", "7"],
             )
             assert result.exit_code != 0
-            assert "rebase" in result.output.lower()
+            # No git commands should be run (no rebase, no push)
+            mock_run.assert_not_called()
 
 
 def test_main_module_block() -> None: