Added config validator and tests for it

.pre-commit-config.yaml

@@ -0,0 +1,8 @@
+
+-
+    repo: git@github.com:pre-commit/pre-commit-hooks
+    sha: cd74dc150c142c3be70b24eaf0b02cae9d235f37
+    hooks:
+        -
+            id: pyflakes
+            files: '*.py'

example_pre-commit-config.yaml

@@ -0,0 +1,14 @@
+
+-
+    repo: git@github.com:pre-commit/pre-commit-hooks
+    sha: cd74dc150c142c3be70b24eaf0b02cae9d235f37
+    hooks:
+        -
+            id: pyflakes
+            files: '*.py'
+        -
+            id: jslint
+            files: '*.js'
+        -
+            id: trim_trailing_whitespace
+            files: '*.py'

pre_commit/clientlib/validate_config.py

@@ -0,0 +1,72 @@
+
+from __future__ import print_function
+
+import argparse
+
+import pre_commit.constants as C
+from pre_commit.clientlib.validate_base import get_validator
+
+
+class InvalidConfigError(ValueError): pass
+
+
+CONFIG_JSON_SCHEMA = {
+    'type': 'array',
+    'minItems': 1,
+    'items': {
+        'type': 'object',
+        'properties': {
+            'repo': {'type': 'string'},
+            'sha': {'type': 'string'},
+            'hooks': {
+                'type': 'array',
+                'minItems': 1,
+                'items': {
+                    'type': 'object',
+                    'properties': {
+                        'id': {'type': 'string'},
+                        'files': {'type': 'string'},
+                        'args': {
+                            'type': 'array',
+                            'minItems': 1,
+                            'items': {'type': 'string'},
+                        },
+                    },
+                    'required': ['id', 'files'],
+                }
+            }
+        },
+        'required': ['repo', 'sha', 'hooks'],
+    }
+}
+
+
+validate_manifest = get_validator(
+    C.CONFIG_FILE,
+    CONFIG_JSON_SCHEMA,
+    InvalidConfigError,
+)
+
+
+def run(argv):
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        'filename',
+        nargs='?', default=None,
+        help='Config filename.  Defaults to {0} at root of git repo'.format(
+            C.CONFIG_FILE,
+        )
+    )
+    args = parser.parse_args(argv)
+
+    try:
+        validate_manifest(args.filename)
+    except InvalidConfigError as e:
+        print(e.args[0])
+        # If we have more than one exception argument print the stringified
+        # version
+        if len(e.args) > 1:
+            print(str(e.args[1]))
+        return 1
+
+    return 0

pre_commit/entry_points.py

@@ -1,6 +1,7 @@
 
 import functools
 
+import pre_commit.clientlib.validate_config
 import pre_commit.clientlib.validate_manifest
 import pre_commit.run
 
@@ -21,3 +22,4 @@ def make_entry_point(entry_point_func):
 
 pre_commit_func = make_entry_point(pre_commit.run.run)
 validate_manifest_func = make_entry_point(pre_commit.clientlib.validate_manifest.run)
+validate_config_func = make_entry_point(pre_commit.clientlib.validate_config.run)

setup.py

@@ -20,6 +20,7 @@ setup(
     entry_points={
         'console_scripts': [
             'pre-commit = pre_commit.entry_points:pre_commit_func',
+            'validate-config = pre_commit.entry_points:validate_config_func',
             'validate-manifest = pre_commit.entry_points:validate_manifest_func',
         ],
     }

tests/clientlib/validate_config_test.py

@@ -0,0 +1,61 @@
+
+import jsonschema
+import jsonschema.exceptions
+import pytest
+
+from pre_commit.clientlib.validate_config import CONFIG_JSON_SCHEMA
+from pre_commit.clientlib.validate_config import run
+
+
+def test_returns_0_for_valid_config():
+    assert run(['example_pre-commit-config.yaml']) == 0
+
+
+def test_returns_0_for_out_manifest():
+    assert run([]) == 0
+
+
+def test_returns_1_for_failing():
+    assert run(['tests/data/valid_yaml_but_invalid_config.yaml']) == 1
+
+def is_valid_according_to_schema(obj, schema):
+    try:
+        jsonschema.validate(obj, schema)
+        return True
+    except jsonschema.exceptions.ValidationError:
+        return False
+
+
+@pytest.mark.parametrize(('manifest_obj', 'expected'), (
+    ([], False),
+    (
+        [{
+          'repo': 'git@github.com:pre-commit/pre-commit-hooks',
+          'sha': 'cd74dc150c142c3be70b24eaf0b02cae9d235f37',
+          'hooks': [
+              {
+                  'id': 'pyflakes',
+                  'files': '*.py',
+              }
+          ]
+        }],
+        True,
+    ),
+    (
+        [{
+          'repo': 'git@github.com:pre-commit/pre-commit-hooks',
+          'sha': 'cd74dc150c142c3be70b24eaf0b02cae9d235f37',
+          'hooks': [
+              {
+                  'id': 'pyflakes',
+                  'files': '*.py',
+                  'args': ['foo', 'bar', 'baz'],
+              }
+          ]
+        }],
+        True,
+    ),
+))
+def test_is_valid_according_to_schema(manifest_obj, expected):
+    ret = is_valid_according_to_schema(manifest_obj, CONFIG_JSON_SCHEMA)
+    assert ret is expected

tests/data/valid_yaml_but_invalid_config.yaml

@@ -0,0 +1,11 @@
+
+-
+    repo: git@github.com:pre-commit/pre-commit-hooks
+    hooks:
+        -
+            id: pyflakes
+        -
+            id: jslint
+        -
+            id: trim_trailing_whitespace
+            files: '*.py'