Extend validate_base to take a load_strategy

pre_commit/clientlib/validate_base.py

@@ -24,7 +24,7 @@ def get_validator(
             exception_type on failure.
     """
 
-    def validate(filename=None):
+    def validate(filename=None, load_strategy=yaml.load):
         filename = filename or os.path.join(git.get_root(), default_filename)
 
         if not os.path.exists(filename):
@@ -33,7 +33,7 @@ def get_validator(
         file_contents = open(filename, 'r').read()
 
         try:
-            obj = yaml.load(file_contents)
+            obj = load_strategy(file_contents)
         except Exception as e:
             raise exception_type(
                 'File {0} is not a valid yaml file'.format(filename), e,

testing/resources/ordering_data_test.yaml

@@ -0,0 +1,2 @@
+foo: bar
+bar: baz

tests/clientlib/validate_base_test.py

@@ -7,6 +7,8 @@ import pytest
 
 from pre_commit import git
 from pre_commit.clientlib.validate_base import get_validator
+from pre_commit.ordereddict import OrderedDict
+from pre_commit.yaml_extensions import ordered_load
 from testing.util import get_resource_path
 
 
@@ -71,3 +73,11 @@ def test_raises_when_additional_validation_fails(additional_validator):
 def test_returns_object_after_validating(noop_validator):
     ret = noop_validator(get_resource_path('array_yaml_file.yaml'))
     assert ret == ['foo', 'bar']
+
+
+def test_load_strategy(noop_validator):
+    ret = noop_validator(
+        get_resource_path('ordering_data_test.yaml'),
+        load_strategy=ordered_load,
+    )
+    assert type(ret) is OrderedDict