From 898a3ea1bb7dc2a3a0a65f8b2019408691c557ff Mon Sep 17 00:00:00 2001
From: Anthony Sottile <asottile@umich.edu>
Date: Fri, 8 Sep 2017 13:19:00 -0700
Subject: [PATCH] Implement `fail_fast`.

---
 pre_commit/clientlib.py    |  1 +
 pre_commit/commands/run.py |  6 ++++--
 pre_commit/runner.py       |  6 +++++-
 tests/commands/run_test.py | 15 +++++++++++++++
 4 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/pre_commit/clientlib.py b/pre_commit/clientlib.py
index e69359b0..7fb49d78 100644
--- a/pre_commit/clientlib.py
+++ b/pre_commit/clientlib.py
@@ -130,6 +130,7 @@ CONFIG_SCHEMA = schema.Map(
     'Config', None,
 
     schema.RequiredRecurse('repos', schema.Array(CONFIG_REPO_DICT)),
+    schema.Optional('fail_fast', schema.check_bool, False),
 )
 
 
diff --git a/pre_commit/commands/run.py b/pre_commit/commands/run.py
index 99232585..505bb54d 100644
--- a/pre_commit/commands/run.py
+++ b/pre_commit/commands/run.py
@@ -169,13 +169,15 @@ def _compute_cols(hooks, verbose):
     return max(cols, 80)
 
 
-def _run_hooks(repo_hooks, args, environ):
+def _run_hooks(config, repo_hooks, args, environ):
     """Actually run the hooks."""
     skips = _get_skips(environ)
     cols = _compute_cols([hook for _, hook in repo_hooks], args.verbose)
     retval = 0
     for repo, hook in repo_hooks:
         retval |= _run_single_hook(hook, repo, args, skips, cols)
+        if retval and config['fail_fast']:
+            break
     if (
             retval and
             args.show_diff_on_failure and
@@ -251,4 +253,4 @@ def run(runner, args, environ=os.environ):
             if not hook['stages'] or args.hook_stage in hook['stages']
         ]
 
-        return _run_hooks(repo_hooks, args, environ)
+        return _run_hooks(runner.config, repo_hooks, args, environ)
diff --git a/pre_commit/runner.py b/pre_commit/runner.py
index 346d6021..d853868a 100644
--- a/pre_commit/runner.py
+++ b/pre_commit/runner.py
@@ -37,10 +37,14 @@ class Runner(object):
     def config_file_path(self):
         return os.path.join(self.git_root, self.config_file)
 
+    @cached_property
+    def config(self):
+        return load_config(self.config_file_path)
+
     @cached_property
     def repositories(self):
         """Returns a tuple of the configured repositories."""
-        repos = load_config(self.config_file_path)['repos']
+        repos = self.config['repos']
         repos = tuple(Repository.create(x, self.store) for x in repos)
         for repo in repos:
             repo.require_installed()
diff --git a/tests/commands/run_test.py b/tests/commands/run_test.py
index 39d3ac0b..53e098b0 100644
--- a/tests/commands/run_test.py
+++ b/tests/commands/run_test.py
@@ -729,3 +729,18 @@ def test_pass_filenames(
     )
     assert expected_out + b'\nHello World' in printed
     assert (b'foo.py' in printed) == pass_filenames
+
+
+def test_fail_fast(
+        cap_out, repo_with_failing_hook, mock_out_store_directory,
+):
+    with cwd(repo_with_failing_hook):
+        with modify_config() as config:
+            # More than one hook
+            config['fail_fast'] = True
+            config['repos'][0]['hooks'] *= 2
+        stage_a_file()
+
+        ret, printed = _do_run(cap_out, repo_with_failing_hook, _get_opts())
+        # it should have only run one hook
+        assert printed.count(b'Failing hook') == 1