Add OrderedDict dependency. Make sure hooks are run in a deterministic order

pre_commit/ordereddict.py

@@ -0,0 +1,10 @@
+from __future__ import absolute_import
+
+# This module serves only as a shim for OrderedDict
+
+try:
+    from collections import OrderedDict
+except ImportError:
+    from orderddict import OrderedDict
+
+__all__ = (OrderedDict.__name__,)

pre_commit/repository.py

@@ -6,6 +6,7 @@ import pre_commit.constants as C
 from pre_commit.clientlib.validate_manifest import validate_manifest
 from pre_commit.hooks_workspace import in_hooks_workspace
 from pre_commit.languages.all import languages
+from pre_commit.ordereddict import OrderedDict
 from pre_commit.util import cached_property
 
 
@@ -29,7 +30,7 @@ class Repository(object):
 
     @cached_property
     def hooks(self):
-        return dict(
+        return OrderedDict(
             (hook['id'], dict(hook, **self.manifest[hook['id']]))
             for hook in self.repo_config['hooks']
         )

setup.py

@@ -1,6 +1,21 @@
+import sys
 from setuptools import find_packages
 from setuptools import setup
 
+
+install_requires = [
+    'argparse',
+    'jsonschema',
+    'plumbum',
+    'pyyaml',
+    'simplejson',
+]
+
+
+if sys.version_info < (2, 7):
+    install_requires.append('ordereddict')
+
+
 setup(
     name='pre_commit',
     version='0.0.0',
@@ -10,13 +25,7 @@ setup(
             'resources/pre-commit.sh'
         ]
     },
-    install_requires=[
+    install_requires=install_requires,
-        'argparse',
-        'jsonschema',
-        'plumbum',
-        'pyyaml',
-        'simplejson',
-    ],
     entry_points={
         'console_scripts': [
             'pre-commit = pre_commit.run:run',