def test_get_valid_ref_without_origin_current_branch(self):
        """Test that _get_valid_ref falls back to default branch when current branch doesn't exist in origin."""
        # Create a new branch that doesn't exist in origin
        self._execute_command(
            'git --no-pager checkout -b new-local-branch', self.local_dir
        )

        # Clear the executed commands to start fresh
        self.executed_commands = []

        ref = self.git_handler._get_valid_ref()
        self.assertIsNotNone(ref)

        # Check that the refs were checked in the correct order
        verify_commands = [
            cmd
            for cmd, _ in self.executed_commands
            if cmd.startswith('git --no-pager rev-parse --verify')
        ]

        # Should have tried origin/new-local-branch first (which doesn't exist)
        self.assertTrue(
            any('origin/new-local-branch' in cmd for cmd in verify_commands)
        )

        # Should have found a valid ref (origin/main or merge-base)
        self.assertNotEqual(ref, 'origin/new-local-branch')
        self.assertTrue(ref == 'origin/main' or 'merge-base' in ref)

        # Verify the ref exists
        result = self._execute_command(
            f'git --no-pager rev-parse --verify {ref}', self.local_dir
        )
        self.assertEqual(result.exit_code, 0)
Test that _get_valid_ref falls back to default branch when current branch doesn't exist in origin.
tests/unit/test_git_handler.py