Merge pull request #2602 from pre-commit/mypy-modules-as-protocols

use modules as protocols

pre_commit/languages/all.py

@@ -1,7 +1,6 @@
 from __future__ import annotations
 
-from typing import Callable
+from typing import Protocol
-from typing import NamedTuple
 from typing import Sequence
 
 from pre_commit.hook import Hook
@@ -27,44 +26,61 @@ from pre_commit.languages import system
 from pre_commit.prefix import Prefix
 
 
-class Language(NamedTuple):
+class Language(Protocol):
-    name: str
     # Use `None` for no installation / environment
-    ENVIRONMENT_DIR: str | None
+    @property
+    def ENVIRONMENT_DIR(self) -> str | None: ...
     # return a value to replace `'default` for `language_version`
-    get_default_version: Callable[[], str]
+    def get_default_version(self) -> str: ...
+
     # return whether the environment is healthy (or should be rebuilt)
-    health_check: Callable[[Prefix, str], str | None]
+    def health_check(
+            self,
+            prefix: Prefix,
+            language_version: str,
+    ) -> str | None:
+        ...
+
     # install a repository for the given language and language_version
-    install_environment: Callable[[Prefix, str, Sequence[str]], None]
+    def install_environment(
+            self,
+            prefix: Prefix,
+            version: str,
+            additional_dependencies: Sequence[str],
+    ) -> None:
+        ...
+
     # execute a hook and return the exit code and output
-    run_hook: Callable[[Hook, Sequence[str], bool], tuple[int, bytes]]
+    def run_hook(
+            self,
+            hook: Hook,
+            file_args: Sequence[str],
+            color: bool,
+    ) -> tuple[int, bytes]:
+        ...
 
 
-# TODO: back to modules + Protocol: https://github.com/python/mypy/issues/5018
+languages: dict[str, Language] = {
-languages = {
+    'conda': conda,
-    # BEGIN GENERATED (testing/gen-languages-all)
+    'coursier': coursier,
-    'conda': Language(name='conda', ENVIRONMENT_DIR=conda.ENVIRONMENT_DIR, get_default_version=conda.get_default_version, health_check=conda.health_check, install_environment=conda.install_environment, run_hook=conda.run_hook),  # noqa: E501
+    'dart': dart,
-    'coursier': Language(name='coursier', ENVIRONMENT_DIR=coursier.ENVIRONMENT_DIR, get_default_version=coursier.get_default_version, health_check=coursier.health_check, install_environment=coursier.install_environment, run_hook=coursier.run_hook),  # noqa: E501
+    'docker': docker,
-    'dart': Language(name='dart', ENVIRONMENT_DIR=dart.ENVIRONMENT_DIR, get_default_version=dart.get_default_version, health_check=dart.health_check, install_environment=dart.install_environment, run_hook=dart.run_hook),  # noqa: E501
+    'docker_image': docker_image,
-    'docker': Language(name='docker', ENVIRONMENT_DIR=docker.ENVIRONMENT_DIR, get_default_version=docker.get_default_version, health_check=docker.health_check, install_environment=docker.install_environment, run_hook=docker.run_hook),  # noqa: E501
+    'dotnet': dotnet,
-    'docker_image': Language(name='docker_image', ENVIRONMENT_DIR=docker_image.ENVIRONMENT_DIR, get_default_version=docker_image.get_default_version, health_check=docker_image.health_check, install_environment=docker_image.install_environment, run_hook=docker_image.run_hook),  # noqa: E501
+    'fail': fail,
-    'dotnet': Language(name='dotnet', ENVIRONMENT_DIR=dotnet.ENVIRONMENT_DIR, get_default_version=dotnet.get_default_version, health_check=dotnet.health_check, install_environment=dotnet.install_environment, run_hook=dotnet.run_hook),  # noqa: E501
+    'golang': golang,
-    'fail': Language(name='fail', ENVIRONMENT_DIR=fail.ENVIRONMENT_DIR, get_default_version=fail.get_default_version, health_check=fail.health_check, install_environment=fail.install_environment, run_hook=fail.run_hook),  # noqa: E501
+    'lua': lua,
-    'golang': Language(name='golang', ENVIRONMENT_DIR=golang.ENVIRONMENT_DIR, get_default_version=golang.get_default_version, health_check=golang.health_check, install_environment=golang.install_environment, run_hook=golang.run_hook),  # noqa: E501
+    'node': node,
-    'lua': Language(name='lua', ENVIRONMENT_DIR=lua.ENVIRONMENT_DIR, get_default_version=lua.get_default_version, health_check=lua.health_check, install_environment=lua.install_environment, run_hook=lua.run_hook),  # noqa: E501
+    'perl': perl,
-    'node': Language(name='node', ENVIRONMENT_DIR=node.ENVIRONMENT_DIR, get_default_version=node.get_default_version, health_check=node.health_check, install_environment=node.install_environment, run_hook=node.run_hook),  # noqa: E501
+    'pygrep': pygrep,
-    'perl': Language(name='perl', ENVIRONMENT_DIR=perl.ENVIRONMENT_DIR, get_default_version=perl.get_default_version, health_check=perl.health_check, install_environment=perl.install_environment, run_hook=perl.run_hook),  # noqa: E501
+    'python': python,
-    'pygrep': Language(name='pygrep', ENVIRONMENT_DIR=pygrep.ENVIRONMENT_DIR, get_default_version=pygrep.get_default_version, health_check=pygrep.health_check, install_environment=pygrep.install_environment, run_hook=pygrep.run_hook),  # noqa: E501
+    'r': r,
-    'python': Language(name='python', ENVIRONMENT_DIR=python.ENVIRONMENT_DIR, get_default_version=python.get_default_version, health_check=python.health_check, install_environment=python.install_environment, run_hook=python.run_hook),  # noqa: E501
+    'ruby': ruby,
-    'r': Language(name='r', ENVIRONMENT_DIR=r.ENVIRONMENT_DIR, get_default_version=r.get_default_version, health_check=r.health_check, install_environment=r.install_environment, run_hook=r.run_hook),  # noqa: E501
+    'rust': rust,
-    'ruby': Language(name='ruby', ENVIRONMENT_DIR=ruby.ENVIRONMENT_DIR, get_default_version=ruby.get_default_version, health_check=ruby.health_check, install_environment=ruby.install_environment, run_hook=ruby.run_hook),  # noqa: E501
+    'script': script,
-    'rust': Language(name='rust', ENVIRONMENT_DIR=rust.ENVIRONMENT_DIR, get_default_version=rust.get_default_version, health_check=rust.health_check, install_environment=rust.install_environment, run_hook=rust.run_hook),  # noqa: E501
+    'swift': swift,
-    'script': Language(name='script', ENVIRONMENT_DIR=script.ENVIRONMENT_DIR, get_default_version=script.get_default_version, health_check=script.health_check, install_environment=script.install_environment, run_hook=script.run_hook),  # noqa: E501
+    'system': system,
-    'swift': Language(name='swift', ENVIRONMENT_DIR=swift.ENVIRONMENT_DIR, get_default_version=swift.get_default_version, health_check=swift.health_check, install_environment=swift.install_environment, run_hook=swift.run_hook),  # noqa: E501
+    # TODO: fully deprecate `python_venv`
-    'system': Language(name='system', ENVIRONMENT_DIR=system.ENVIRONMENT_DIR, get_default_version=system.get_default_version, health_check=system.health_check, install_environment=system.install_environment, run_hook=system.run_hook),  # noqa: E501
+    'python_venv': python,
-    # END GENERATED
 }
-# TODO: fully deprecate `python_venv`
-languages['python_venv'] = languages['python']
 all_languages = sorted(languages)

testing/gen-languages-all

@@ -1,30 +0,0 @@
-#!/usr/bin/env python3
-from __future__ import annotations
-
-import sys
-
-LANGUAGES = (
-    'conda', 'coursier', 'dart', 'docker', 'docker_image', 'dotnet', 'fail',
-    'golang', 'lua', 'node', 'perl', 'pygrep', 'python', 'r', 'ruby', 'rust',
-    'script', 'swift', 'system',
-)
-FIELDS = (
-    'ENVIRONMENT_DIR', 'get_default_version', 'health_check',
-    'install_environment', 'run_hook',
-)
-
-
-def main() -> int:
-    print(f'    # BEGIN GENERATED ({sys.argv[0]})')
-    for lang in LANGUAGES:
-        parts = [f'    {lang!r}: Language(name={lang!r}']
-        for k in FIELDS:
-            parts.append(f', {k}={lang}.{k}')
-        parts.append('),  # noqa: E501')
-        print(''.join(parts))
-    print('    # END GENERATED')
-    return 0
-
-
-if __name__ == '__main__':
-    raise SystemExit(main())

tests/repository_test.py

@@ -133,9 +133,11 @@ def test_python_hook(tempdir_factory, store):
 def test_python_hook_default_version(tempdir_factory, store):
     # make sure that this continues to work for platforms where default
     # language detection does not work
-    returns_default = mock.Mock(return_value=C.DEFAULT)
+    with mock.patch.object(
-    lang = languages['python']._replace(get_default_version=returns_default)
+            python,
-    with mock.patch.dict(languages, python=lang):
+            'get_default_version',
+            return_value=C.DEFAULT,
+    ):
         test_python_hook(tempdir_factory, store)
 
 
@@ -247,9 +249,11 @@ def test_run_a_node_hook(tempdir_factory, store):
 def test_run_a_node_hook_default_version(tempdir_factory, store):
     # make sure that this continues to work for platforms where node is not
     # installed at the system
-    returns_default = mock.Mock(return_value=C.DEFAULT)
+    with mock.patch.object(
-    lang = languages['node']._replace(get_default_version=returns_default)
+            node,
-    with mock.patch.dict(languages, node=lang):
+            'get_default_version',
+            return_value=C.DEFAULT,
+    ):
         test_run_a_node_hook(tempdir_factory, store)