fix: Allow skipping aliased hooks

There are situations where a hook with the same ID will be used multiple times, but with
differing configurations. In the event that one of those configurations should not
desired (or can't) be run in pre-commit CI it should be possible to skip using the
`alias` configuration parameter. This adds support for the `alias` as an alternate to
just `id` in the `ci:skip` list.

Author: blarghmatey

pre_commit_ci_config.py

@@ -25,9 +25,11 @@ def _check_autoupdate_branch(val: str) -> None:
 class ValidateSkip:
     def check(self, dct: dict[str, Any]) -> None:
         all_ids = {
-            hook['id']
+            hook_id
             for repo in dct['repos']
             for hook in repo['hooks']
+            for hook_id in (hook['id'], hook.get('alias'))
+            if hook_id is not None
         }
         unexpected_skip = set(dct.get('ci', {}).get('skip', ())) - all_ids
         if unexpected_skip:

tests/pre_commit_ci_config_test.py

@@ -94,6 +94,24 @@ def test_skip_referencing_missing_hook():
     )
 
 
+def test_skip_references_hook_with_alias():
+    cfg = {
+        'ci': {'skip': ['alternate-identity']},
+        'repos': [
+            {
+                'repo': 'meta',
+                'hooks': [
+                    {
+                        'id': 'identity',
+                        'alias': 'alternate-identity',
+                    },
+                ],
+            },
+        ],
+    }
+    cfgv.validate(cfg, SCHEMA)
+
+
 def test_main_ok(tmpdir):
     cfg_s = '''\
 ci: