Add --no-stash option.

pre_commit/commands.py

@@ -21,6 +21,7 @@ from pre_commit.jsonschema_extensions import remove_defaults
 from pre_commit.logging_handler import LoggingHandler
 from pre_commit.repository import Repository
 from pre_commit.staged_files_only import staged_files_only
+from pre_commit.util import noop_context
 
 
 logger = logging.getLogger('pre_commit')
@@ -233,7 +234,12 @@ def run(runner, args, write=sys.stdout.write):
     logger.addHandler(LoggingHandler(args.color, write=write))
     logger.setLevel(logging.INFO)
 
-    with staged_files_only(runner.cmd_runner):
+    if args.no_stash:
+        ctx = noop_context()
+    else:
+        ctx = staged_files_only(runner.cmd_runner)
+
+    with ctx:
         if args.hook:
             return _run_hook(runner, args.hook, args, write=write)
         else:

pre_commit/run.py

@@ -31,6 +31,10 @@ def run(argv):
         '--color', default='auto', type=color.use_color,
         help='Whether to use color in output.  Defaults to `auto`',
     )
+    run_parser.add_argument(
+        '--no-stash', default=False, action='store_true',
+        help='Use this option to prevent auto stashing of unstaged files.',
+    )
     run_parser.add_argument('--verbose', '-v', action='store_true', default=False)
 
     help = subparsers.add_parser('help', help='Show help for a specific command.')

pre_commit/util.py

@@ -62,3 +62,9 @@ def clean_path_on_failure(path):
         if os.path.exists(path):
             shutil.rmtree(path)
         raise
+
+
+# TODO: asottile.contextlib this with a forward port of nested
+@contextlib.contextmanager
+def noop_context():
+    yield