Implement types filtering

pre_commit/commands/run.py

@@ -6,18 +6,24 @@ import os
 import subprocess
 import sys
 
+from identify.identify import tags_from_path
+
 from pre_commit import color
 from pre_commit import git
 from pre_commit import output
 from pre_commit.output import get_hook_message
 from pre_commit.staged_files_only import staged_files_only
 from pre_commit.util import cmd_output
+from pre_commit.util import memoize_by_cwd
 from pre_commit.util import noop_context
 
 
 logger = logging.getLogger('pre_commit')
 
 
+tags_from_path = memoize_by_cwd(tags_from_path)
+
+
 def _get_skips(environ):
     skips = environ.get('SKIP', '')
     return {skip.strip() for skip in skips.split(',') if skip.strip()}
@@ -37,6 +43,14 @@ def get_changed_files(new, old):
     )[1].splitlines()
 
 
+def filter_filenames_by_types(filenames, types):
+    types = frozenset(types)
+    return tuple(
+        filename for filename in filenames
+        if tags_from_path(filename) >= types
+    )
+
+
 def get_filenames(args, include_expr, exclude_expr):
     if args.origin and args.source:
         getter = git.get_files_matching(
@@ -59,6 +73,7 @@ NO_FILES = '(no files to check)'
 
 def _run_single_hook(hook, repo, args, skips, cols):
     filenames = get_filenames(args, hook['files'], hook['exclude'])
+    filenames = filter_filenames_by_types(filenames, hook['types'])
     if hook['id'] in skips:
         output.write(get_hook_message(
             _hook_msg_start(hook, args.verbose),

testing/resources/types_repo/.pre-commit-hooks.yaml

@@ -0,0 +1,5 @@
+-   id: python-files
+    name: Python files
+    entry: bin/hook.sh
+    language: script
+    types: [python]

testing/resources/types_repo/bin/hook.sh

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+echo $@
+exit 1

tests/commands/run_test.py

@@ -153,6 +153,19 @@ def test_hook_that_modifies_but_returns_zero(
         )
 
 
+def test_types_hook_repository(
+        cap_out, tempdir_factory, mock_out_store_directory,
+):
+    git_path = make_consuming_repo(tempdir_factory, 'types_repo')
+    with cwd(git_path):
+        stage_a_file('bar.py')
+        stage_a_file('bar.notpy')
+        ret, printed = _do_run(cap_out, git_path, _get_opts())
+        assert ret == 1
+        assert b'bar.py' in printed
+        assert b'bar.notpy' not in printed
+
+
 def test_show_diff_on_failure(
         capfd, cap_out, tempdir_factory, mock_out_store_directory,
 ):