update-checkout: Do not update repository if not listed in the given branch-scheme

Consider two branch-schemes: one maps all repositories, the other—a subset.
Suppose repositories have been cloned using the first branch scheme. Previously,
a successive update using the second branch-scheme would cause update-checkout
to fail in an attempt to query the branch-scheme about the target branch for a
repository it does not map, even though the update, given no further errors, can
otherwise be considered successful.

Author: AnthonyLatsis

utils/update_checkout/tests/scheme_mock.py

@@ -28,7 +28,7 @@
         ('A.txt', 'a'),
     ],
     'repo2': [
-        # This is a series of changes to repo1. (File, NewContents)
+        # This is a series of changes to repo2. (File, NewContents)
         ('X.txt', 'X'),
         ('Y.txt', 'Y'),
         ('X.txt', 'z'),
@@ -97,7 +97,7 @@ def get_config_path(base_dir):
     return os.path.join(base_dir, 'test-config.json')
 
 
-def setup_mock_remote(base_dir):
+def setup_mock_remote(base_dir, base_config):
     create_dir(base_dir)
 
     # We use local as a workspace for creating commits.
@@ -130,7 +130,6 @@ def setup_mock_remote(base_dir):
             call_quietly(['git', 'push', 'origin', 'main'],
                          cwd=local_repo_path)
 
-    base_config = MOCK_CONFIG
     https_clone_pattern = os.path.join('file://%s' % REMOTE_PATH, '%s')
     base_config['https-clone-pattern'] = https_clone_pattern
 
@@ -153,6 +152,7 @@ class SchemeMockTestCase(unittest.TestCase):
     def __init__(self, *args, **kwargs):
         super(SchemeMockTestCase, self).__init__(*args, **kwargs)
 
+        self.config = MOCK_CONFIG.copy()
         self.workspace = os.getenv(BASEDIR_ENV_VAR)
         if self.workspace is None:
             raise RuntimeError('Misconfigured test suite! Environment '
@@ -167,11 +167,19 @@ def __init__(self, *args, **kwargs):
 
     def setUp(self):
         create_dir(self.source_root)
-        (self.local_path, self.remote_path) = setup_mock_remote(self.workspace)
+        (self.local_path, self.remote_path) = setup_mock_remote(
+            self.workspace, self.config
+        )
 
     def tearDown(self):
         teardown_mock_remote(self.workspace)
 
     def call(self, *args, **kwargs):
         kwargs['cwd'] = self.source_root
         call_quietly(*args, **kwargs)
+
+    def get_all_repos(self):
+        return list(self.config["repos"].keys())
+
+    def add_branch_scheme(self, name, scheme):
+        self.config["branch-schemes"][name] = scheme

utils/update_checkout/tests/test_clone.py

@@ -10,6 +10,8 @@
 #
 # ===----------------------------------------------------------------------===#
 
+import os
+
 from . import scheme_mock
 
 
@@ -23,3 +25,51 @@ def test_simple_clone(self):
                    '--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)
+            self.assertTrue(os.path.isdir(repo_path))
+
+
+class SchemeWithMissingRepoTestCase(scheme_mock.SchemeMockTestCase):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        self.base_args = [
+            self.update_checkout_path,
+            "--config",
+            self.config_path,
+            "--source-root",
+            self.source_root,
+        ]
+
+        repos = self.get_all_repos()
+        repos.pop()
+
+        self.scheme_name = "missing-repo"
+        scheme = {
+            "aliases": [self.scheme_name],
+            "repos": dict((repo, "main") for repo in repos),
+        }
+        self.add_branch_scheme(self.scheme_name, scheme)
+
+    # Test that we do not clone a repository that is not listed in the
+    # given branch-scheme.
+    def test_clone(self):
+        self.call(self.base_args + ["--scheme", self.scheme_name, "--clone"])
+
+        missing_repo_path = os.path.join(
+            self.source_root, self.get_all_repos().pop()
+        )
+        self.assertFalse(os.path.isdir(missing_repo_path))
+
+    # Test that we do not update a repository that is not listed in the given
+    # branch-scheme---doing so will cause an irrelevant failure in an attempt
+    # to query the branch-scheme about the target branch for that repository.
+    def test_update(self):
+        # First, clone using the default branch-scheme, which has mappings for
+        # all repositories.
+        self.call(self.base_args + ["--clone"])
+
+        # Then, update using our custom scheme---a subset of the default one.
+        self.call(self.base_args + ["--scheme", self.scheme_name])

utils/update_checkout/update_checkout/update_checkout.py

@@ -266,6 +266,20 @@ def update_all_repositories(args, config, scheme_name, cross_repos_pr):
         if repo_name in args.skip_repository_list:
             print("Skipping update of '" + repo_name + "', requested by user")
             continue
+
+        # If the repository is not listed in the branch-scheme, skip it.
+        if scheme_map and repo_name not in scheme_map:
+            # If the repository exists locally, notify we are skipping it.
+            if os.path.isdir(os.path.join(args.source_root, repo_name)):
+                print(
+                    "Skipping update of '"
+                    + repo_name
+                    + "', repository not listed in the '"
+                    + scheme_name
+                    + "' branch-scheme"
+                )
+            continue
+
         my_args = [args.source_root, config,
                    repo_name,
                    scheme_name,