pre_commit: expose fail-fast argument for run subcommand

This patch exposes the fail-fast feature as a command-line argument for the run
subcommand, allowing to run pre-commit to stop at the first failed hook without
the need of temporarily writing it to the configuration file when temporarily
needed.

Signed-off-by: Luís Ferreira <contact@lsferreira.net>

pre_commit/commands/hook_impl.py

@@ -69,6 +69,7 @@ def _ns(
         color: bool,
         *,
         all_files: bool = False,
+        fail_fast: bool = False,
         remote_branch: Optional[str] = None,
         local_branch: Optional[str] = None,
         from_ref: Optional[str] = None,
@@ -91,6 +92,7 @@ def _ns(
         remote_url=remote_url,
         commit_msg_filename=commit_msg_filename,
         all_files=all_files,
+        fail_fast=fail_fast,
         checkout_type=checkout_type,
         is_squash_merge=is_squash_merge,
         rewrite_command=rewrite_command,

pre_commit/commands/run.py

@@ -290,7 +290,7 @@ def _run_hooks(
             verbose=args.verbose, use_color=args.color,
         )
         retval |= current_retval
-        if retval and config['fail_fast']:
+        if retval and (config['fail_fast'] or args.fail_fast):
             break
     if retval and args.show_diff_on_failure and prior_diff:
         if args.all_files:

pre_commit/main.py

@@ -85,6 +85,10 @@ def _add_run_options(parser: argparse.ArgumentParser) -> None:
         '--all-files', '-a', action='store_true', default=False,
         help='Run on all the files in the repo.',
     )
+    mutex_group.add_argument(
+        '--fail-fast', action='store_true',
+        help='Stop running hooks after the first failure',
+    )
     mutex_group.add_argument(
         '--files', nargs='*', default=[],
         help='Specific filenames to run hooks on.',

testing/util.py

@@ -57,6 +57,7 @@ xfailif_windows = pytest.mark.xfail(os.name == 'nt', reason='windows')
 
 def run_opts(
         all_files=False,
+        fail_fast=False,
         files=(),
         color=False,
         verbose=False,
@@ -78,6 +79,7 @@ def run_opts(
     assert not (all_files and files)
     return auto_namedtuple(
         all_files=all_files,
+        fail_fast=fail_fast,
         files=files,
         color=color,
         verbose=verbose,

tests/commands/run_test.py

@@ -973,7 +973,7 @@ def test_pass_filenames(
     assert (b'foo.py' in printed) == pass_filenames
 
 
-def test_fail_fast(cap_out, store, repo_with_failing_hook):
+def test_fail_fast_config(cap_out, store, repo_with_failing_hook):
     with modify_config() as config:
         # More than one hook
         config['fail_fast'] = True
@@ -985,6 +985,19 @@ def test_fail_fast(cap_out, store, repo_with_failing_hook):
     assert printed.count(b'Failing hook') == 1
 
 
+def test_fail_fast_args(cap_out, store, repo_with_failing_hook):
+    with modify_config() as config:
+        # More than one hook
+        config['repos'][0]['hooks'] *= 2
+    stage_a_file()
+
+    ret, printed = _do_run(
+        cap_out, store, repo_with_failing_hook, run_opts(fail_fast=True),
+    )
+    # it should have only run one hook
+    assert printed.count(b'Failing hook') == 1
+
+
 def test_classifier_removes_dne():
     classifier = Classifier(('this_file_does_not_exist',))
     assert classifier.filenames == []