Moving from aspy.yaml to ruamel.yaml in order to preserve comments when using autoupdate - fixes #210

pre_commit/clientlib/validate_base.py

@@ -9,9 +9,9 @@ import sys
 import jsonschema
 import jsonschema.exceptions
 import pkg_resources
-import yaml
 
 from pre_commit.jsonschema_extensions import apply_defaults
+from pre_commit.yaml import yaml_load
 
 
 def is_regex_valid(regex):
@@ -36,7 +36,7 @@ def get_validator(
             the object read from the file.  The function should either raise
             exception_type on failure.
     """
-    def validate(filename, load_strategy=yaml.load):
+    def validate(filename, load_strategy=yaml_load):
         if not os.path.exists(filename):
             raise exception_type('File {} does not exist'.format(filename))
 

pre_commit/commands/autoupdate.py

@@ -4,9 +4,6 @@ from __future__ import unicode_literals
 import logging
 import sys
 
-from aspy.yaml import ordered_dump
-from aspy.yaml import ordered_load
-
 import pre_commit.constants as C
 from pre_commit.clientlib.validate_config import CONFIG_JSON_SCHEMA
 from pre_commit.clientlib.validate_config import is_local_hooks
@@ -18,6 +15,8 @@ from pre_commit.repository import Repository
 from pre_commit.util import CalledProcessError
 from pre_commit.util import cmd_output
 from pre_commit.util import cwd
+from pre_commit.yaml import yaml_dump
+from pre_commit.yaml import yaml_load
 
 
 logger = logging.getLogger('pre_commit')
@@ -79,7 +78,7 @@ def autoupdate(runner):
 
     input_configs = load_config(
         runner.config_file_path,
-        load_strategy=ordered_load,
+        load_strategy=yaml_load,
     )
 
     for repo_config in input_configs:
@@ -111,7 +110,7 @@ def autoupdate(runner):
     if changed:
         with open(runner.config_file_path, 'w') as config_file:
             config_file.write(
-                ordered_dump(
+                yaml_dump(
                     remove_defaults(output_configs, CONFIG_JSON_SCHEMA),
                     **C.YAML_DUMP_KWARGS
                 )

pre_commit/yaml.py

@@ -0,0 +1,11 @@
+from ruamel import yaml
+
+
+def yaml_dump(obj, **kwargs):
+    "Ensure order & comments preservation"
+    return yaml.dump(obj, Dumper=yaml.RoundTripDumper, **kwargs)
+
+
+def yaml_load(content):
+    "Ensure order & comments preservation"
+    return yaml.load(content, Loader=yaml.RoundTripLoader)