deprecate python_venv language

tests/commands/migrate_config_test.py

@@ -134,6 +134,39 @@ def test_migrate_config_sha_to_rev(tmpdir):
     )
 
 
+def test_migrate_config_language_python_venv(tmp_path):
+    src = '''\
+repos:
+-   repo: local
+    hooks:
+    -   id: example
+        name: example
+        entry: example
+        language: python_venv
+    -   id: example
+        name: example
+        entry: example
+        language: system
+'''
+    expected = '''\
+repos:
+-   repo: local
+    hooks:
+    -   id: example
+        name: example
+        entry: example
+        language: python
+    -   id: example
+        name: example
+        entry: example
+        language: system
+'''
+    cfg = tmp_path.joinpath('cfg.yaml')
+    cfg.write_text(src)
+    assert migrate_config(str(cfg)) == 0
+    assert cfg.read_text() == expected
+
+
 def test_migrate_config_invalid_yaml(tmpdir):
     contents = '['
     cfg = tmpdir.join(C.CONFIG_FILE)

tests/languages/all_test.py

@@ -0,0 +1,7 @@
+from __future__ import annotations
+
+from pre_commit.languages.all import languages
+
+
+def test_python_venv_is_an_alias_to_python():
+    assert languages['python_venv'] is languages['python']

tests/repository_test.py

@@ -129,11 +129,21 @@ def test_python_hook_weird_setup_cfg(in_git_dir, tempdir_factory, store):
     )
 
 
-def test_python_venv(tempdir_factory, store):
-    _test_hook_repo(
-        tempdir_factory, store, 'python_venv_hooks_repo',
-        'foo', [os.devnull],
-        f'[{os.devnull!r}]\nHello World\n'.encode(),
+def test_python_venv_deprecation(store, caplog):
+    config = {
+        'repo': 'local',
+        'hooks': [{
+            'id': 'example',
+            'name': 'example',
+            'language': 'python_venv',
+            'entry': 'echo hi',
+        }],
+    }
+    _get_hook(config, store, 'example')
+    assert caplog.messages[-1] == (
+        '`repo: local` uses deprecated `language: python_venv`.  '
+        'This is an alias for `language: python`.  '
+        'Often `pre-commit autoupdate --repo local` will fix this.'
     )