Add support for meta hooks

pre_commit/clientlib.py

@@ -98,6 +98,8 @@ def validate_manifest_main(argv=None):
 
 
 _LOCAL_SENTINEL = 'local'
+_META_SENTINEL = 'meta'
+
 CONFIG_HOOK_DICT = schema.Map(
     'Hook', 'id',
 
@@ -121,7 +123,8 @@ CONFIG_REPO_DICT = schema.Map(
 
     schema.Conditional(
         'sha', schema.check_string,
-        condition_key='repo', condition_value=schema.Not(_LOCAL_SENTINEL),
+        condition_key='repo',
+        condition_value=schema.NotIn((_LOCAL_SENTINEL, _META_SENTINEL)),
         ensure_absent=True,
     ),
 )
@@ -138,6 +141,10 @@ def is_local_repo(repo_entry):
     return repo_entry['repo'] == _LOCAL_SENTINEL
 
 
+def is_meta_repo(repo_entry):
+    return repo_entry['repo'] == _META_SENTINEL
+
+
 class InvalidConfigError(FatalError):
     pass
 

pre_commit/repository.py

@@ -5,6 +5,7 @@ import json
 import logging
 import os
 import shutil
+import sys
 from collections import defaultdict
 
 import pkg_resources
@@ -14,6 +15,7 @@ import pre_commit.constants as C
 from pre_commit import five
 from pre_commit import git
 from pre_commit.clientlib import is_local_repo
+from pre_commit.clientlib import is_meta_repo
 from pre_commit.clientlib import MANIFEST_HOOK_DICT
 from pre_commit.languages.all import languages
 from pre_commit.languages.helpers import environment_dir
@@ -128,6 +130,8 @@ class Repository(object):
     def create(cls, config, store):
         if is_local_repo(config):
             return LocalRepository(config, store)
+        elif is_meta_repo(config):
+            return MetaRepository(config, store)
         else:
             return cls(config, store)
 
@@ -242,6 +246,45 @@ class LocalRepository(Repository):
         return tuple(ret)
 
 
+class MetaRepository(LocalRepository):
+    meta_hooks = {
+        'test-hook': {
+            'name': 'Test Hook',
+            'files': '',
+            'language': 'system',
+            'entry': 'echo "Hello World!"',
+            'always_run': True,
+        },
+    }
+
+    @cached_property
+    def hooks(self):
+        for hook in self.repo_config['hooks']:
+            if hook['id'] not in self.meta_hooks:
+                logger.error(
+                    '`{}` is not a valid meta hook.  '
+                    'Typo? Perhaps it is introduced in a newer version?  '
+                    'Often `pre-commit autoupdate` fixes this.'.format(
+                        hook['id'],
+                    ),
+                )
+                exit(1)
+
+        return tuple(
+            (
+                hook['id'],
+                apply_defaults(
+                    validate(
+                        dict(self.meta_hooks[hook['id']], **hook),
+                        MANIFEST_HOOK_DICT,
+                    ),
+                    MANIFEST_HOOK_DICT,
+                ),
+            )
+            for hook in self.repo_config['hooks']
+        )
+
+
 class _UniqueList(list):
     def __init__(self):
         self._set = set()

pre_commit/schema.py

@@ -101,6 +101,9 @@ def _check_conditional(self, dct):
         if isinstance(self.condition_value, Not):
             op = 'is'
             cond_val = self.condition_value.val
+        elif isinstance(self.condition_value, NotIn):
+            op = 'is any of'
+            cond_val = self.condition_value.values
         else:
             op = 'is not'
             cond_val = self.condition_value
@@ -206,6 +209,14 @@ class Not(object):
         return other is not MISSING and other != self.val
 
 
+class NotIn(object):
+    def __init__(self, values):
+        self.values = values
+
+    def __eq__(self, other):
+        return other is not MISSING and other not in self.values
+
+
 def check_any(_):
     pass
 

tests/commands/run_test.py

@@ -645,6 +645,31 @@ def test_local_hook_fails(
     )
 
 
+def test_meta_hook_passes(
+        cap_out, repo_with_passing_hook, mock_out_store_directory,
+):
+    config = OrderedDict((
+        ('repo', 'meta'),
+        (
+            'hooks', (
+                OrderedDict((
+                    ('id', 'test-hook'),
+                )),
+            ),
+        ),
+    ))
+    add_config_to_repo(repo_with_passing_hook, config)
+
+    _test_run(
+        cap_out,
+        repo_with_passing_hook,
+        opts={'verbose': True},
+        expected_outputs=[b'Hello World!'],
+        expected_ret=0,
+        stage=False,
+    )
+
+
 @pytest.yield_fixture
 def modified_config_repo(repo_with_passing_hook):
     with modify_config(repo_with_passing_hook, commit=False) as config:

tests/repository_test.py

@@ -709,6 +709,18 @@ def test_hook_id_not_present(tempdir_factory, store, fake_log_handler):
     )
 
 
+def test_meta_hook_not_present(store, fake_log_handler):
+    config = {'repo': 'meta', 'hooks': [{'id': 'i-dont-exist'}]}
+    repo = Repository.create(config, store)
+    with pytest.raises(SystemExit):
+        repo.require_installed()
+    assert fake_log_handler.handle.call_args[0][0].msg == (
+        '`i-dont-exist` is not a valid meta hook.  '
+        'Typo? Perhaps it is introduced in a newer version?  '
+        'Often `pre-commit autoupdate` fixes this.'
+    )
+
+
 def test_too_new_version(tempdir_factory, store, fake_log_handler):
     path = make_repo(tempdir_factory, 'script_hooks_repo')
     with modify_manifest(path) as manifest:

tests/schema_test.py

@@ -19,6 +19,7 @@ from pre_commit.schema import load_from_filename
 from pre_commit.schema import Map
 from pre_commit.schema import MISSING
 from pre_commit.schema import Not
+from pre_commit.schema import NotIn
 from pre_commit.schema import Optional
 from pre_commit.schema import OptionalNoDefault
 from pre_commit.schema import remove_defaults
@@ -107,6 +108,16 @@ def test_not(val, expected):
     assert (compared == val) is expected
 
 
+@pytest.mark.parametrize(
+    ('values', 'expected'),
+    (('bar', True), ('foo', False), (MISSING, False)),
+)
+def test_not_in(values, expected):
+    compared = NotIn(('baz', 'foo'))
+    assert (values == compared) is expected
+    assert (compared == values) is expected
+
+
 trivial_array_schema = Array(Map('foo', 'id'))
 
 
@@ -196,6 +207,13 @@ map_conditional_absent_not = Map(
         condition_key='key', condition_value=Not(True), ensure_absent=True,
     ),
 )
+map_conditional_absent_not_in = Map(
+    'foo', 'key',
+    Conditional(
+        'key2', check_bool,
+        condition_key='key', condition_value=NotIn((1, 2)), ensure_absent=True,
+    ),
+)
 
 
 @pytest.mark.parametrize('schema', (map_conditional, map_conditional_not))
@@ -248,6 +266,19 @@ def test_ensure_absent_conditional_not():
     )
 
 
+def test_ensure_absent_conditional_not_in():
+    with pytest.raises(ValidationError) as excinfo:
+        validate({'key': 1, 'key2': True}, map_conditional_absent_not_in)
+    _assert_exception_trace(
+        excinfo.value,
+        (
+            'At foo(key=1)',
+            'Expected key2 to be absent when key is any of (1, 2), '
+            'found key2: True',
+        ),
+    )
+
+
 def test_no_error_conditional_absent():
     validate({}, map_conditional_absent)
     validate({}, map_conditional_absent_not)