Complete update-checkout stash test

utils/update_checkout/tests/test_stash.py

@@ -0,0 +1,42 @@
+# ===--- test_stash.py -----------------------------------------------------===#
+#
+# This source file is part of the Swift.org open source project
+#
+# Copyright (c) 2024 Apple Inc. and the Swift project authors
+# Licensed under Apache License v2.0 with Runtime Library Exception
+#
+# See https:#swift.org/LICENSE.txt for license information
+# See https:#swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+#
+# ===----------------------------------------------------------------------===#
+
+from . import scheme_mock
+import os
+
+class StashTestCase(scheme_mock.SchemeMockTestCase):
+    def __init__(self, *args, **kwargs):
+        super(StashTestCase, self).__init__(*args, **kwargs)
+
+    def test_stash_untracked_files(self):
+        self.call([self.update_checkout_path,
+                   '--config', self.config_path,
+                   '--source-root', self.source_root,
+                   '--clone'])
+
+        for repo in self.get_all_repos():
+            repo_path = os.path.join(self.source_root, repo)
+            with open(os.path.join(repo_path, 'untracked_file.txt'), 'w') as f:
+                f.write('This is an untracked file.')
+
+        self.call([self.update_checkout_path,
+                   '--config', self.config_path,
+                   '--source-root', self.source_root,
+                   '--stash'])
+
+        for repo in self.get_all_repos():
+            repo_path = os.path.join(self.source_root, repo)
+            untracked_file_path = os.path.join(repo_path, 'untracked_file.txt')
+            self.assertFalse(
+                os.path.exists(untracked_file_path),
+                f"{untracked_file_path} should be stashed and not present in the working directory."
+            )