Pretty yaml

.pre-commit-hooks.yaml

@@ -49,6 +49,12 @@
     entry: pretty-format-json
     language: python
     files: \.json$
+-   id: pretty-format-yaml
+    name: Pretty format YAML
+    description: This hook sets a standard for formatting YAML files.
+    entry: pretty-format-yaml
+    language: python
+    files: \.(yaml|yml|eyaml)$
 -   id: check-merge-conflict
     name: Check for merge conflicts
     description: Check for files that contain merge conflict strings.

README.md

@@ -64,6 +64,12 @@ Add this to your `.pre-commit-config.yaml`
     - `--indent ...` - Control the indentation (either a number for a number of spaces or a string of whitespace).  Defaults to 4 spaces.
     - `--no-sort-keys` - when autofixing, retain the original key ordering (instead of sorting the keys)
     - `--top-keys comma,separated,keys` - Keys to keep at the top of mappings.
+- `pretty-format-yaml` - Checks that all your YAML files are pretty.  "Pretty"
+  here means that keys are sorted and indented.  You can configure this with
+  the following commandline options:
+    - `--autofix` - automatically format yaml files
+    - `--default_style`, `--default_flow_style`, `--canonical`, `--indent`, `--width`, `--allow_unicode`, `--line_break`, `--encoding`, `--explicit_start`, `--explicit_end`, `--version`, `--tags` - define how a pretty YAML file looks like.
+        The parameters are passed as kwargs into yaml.safe_dump method provided by [pyyaml package](http://pyyaml.org/wiki/PyYAMLDocumentation). Our suggestion of pretty YAML file is `-indent=4 --default_flow_style=False`.
 - `requirements-txt-fixer` - Sorts entries in requirements.txt
 - `trailing-whitespace` - Trims trailing whitespace.
     - Markdown linebreak trailing spaces preserved for `.md` and`.markdown`;

hooks.yaml

@@ -49,6 +49,12 @@
     entry: pretty-format-json
     language: python
     files: \.json$
+-   id: pretty-format-yaml
+    name: Pretty format YAML
+    description: This hook sets a standard for formatting YAML files.
+    entry: pretty-format-yaml
+    language: python
+    files: \.(yaml|yml|eyaml)$
 -   id: check-merge-conflict
     name: Check for merge conflicts
     description: Check for files that contain merge conflict strings.

pre_commit_hooks/pretty_format_yaml.py

@@ -0,0 +1,127 @@
+from __future__ import print_function
+
+import argparse
+import sys
+
+import yaml
+
+
+def _get_pretty_format(content, **kwargs):
+    return yaml.safe_dump(yaml.safe_load(content), **kwargs)
+
+
+def _autofix(filename, new_contents):
+    print("Fixing file {0}".format(filename))
+    with open(filename, 'w') as f:
+        f.write(new_contents)
+
+
+def filter_argument(accepted_values):
+    def _validate(s):
+        try:
+            return {str(v): v for v in accepted_values}[s]
+        except:
+            raise argparse.ArgumentTypeError('Accepted values are: {}'.format(accepted_values))
+    return _validate
+
+
+def none_or_boolean_argument(s):
+    return filter_argument([None, True, False])(s)
+
+
+def pretty_format_yaml(argv=None):
+    parser = argparse.ArgumentParser()
+
+    parser.add_argument(
+        '--autofix',
+        action='store_true',
+        dest='autofix',
+        help='Automatically fixes encountered not-pretty-formatted files',
+    )
+
+    parser.add_argument(
+        '--default_style',
+        help='PyYAML dump parameter. More info on http://pyyaml.org/wiki/PyYAMLDocumentation#Dumper'
+    )
+    parser.add_argument(
+        '--default_flow_style', type=none_or_boolean_argument,
+        help='PyYAML dump parameter. More info on http://pyyaml.org/wiki/PyYAMLDocumentation#Dumper'
+    )
+    parser.add_argument(
+        '--canonical', type=none_or_boolean_argument,
+        help='PyYAML dump parameter. More info on http://pyyaml.org/wiki/PyYAMLDocumentation#Dumper'
+    )
+    parser.add_argument(
+        '--indent', type=int,
+        help='PyYAML dump parameter. More info on http://pyyaml.org/wiki/PyYAMLDocumentation#Dumper'
+    )
+    parser.add_argument(
+        '--width', type=int,
+        help='PyYAML dump parameter. More info on http://pyyaml.org/wiki/PyYAMLDocumentation#Dumper'
+    )
+    parser.add_argument(
+        '--allow_unicode', type=none_or_boolean_argument,
+        help='PyYAML dump parameter. More info on http://pyyaml.org/wiki/PyYAMLDocumentation#Dumper'
+    )
+    parser.add_argument(
+        '--line_break', type=none_or_boolean_argument,
+        help='PyYAML dump parameter. More info on http://pyyaml.org/wiki/PyYAMLDocumentation#Dumper'
+    )
+    parser.add_argument(
+        '--encoding',
+        help='PyYAML dump parameter. More info on http://pyyaml.org/wiki/PyYAMLDocumentation#Dumper'
+    )
+    parser.add_argument(
+        '--explicit_start', type=none_or_boolean_argument,
+        help='PyYAML dump parameter. More info on http://pyyaml.org/wiki/PyYAMLDocumentation#Dumper'
+    )
+    parser.add_argument(
+        '--explicit_end', type=none_or_boolean_argument,
+        help='PyYAML dump parameter. More info on http://pyyaml.org/wiki/PyYAMLDocumentation#Dumper'
+    )
+    parser.add_argument(
+        '--version',
+        help='PyYAML dump parameter. More info on http://pyyaml.org/wiki/PyYAMLDocumentation#Dumper'
+    )
+    parser.add_argument(
+        '--tags',
+        help='PyYAML dump parameter. More info on http://pyyaml.org/wiki/PyYAMLDocumentation#Dumper'
+    )
+    parser.add_argument('filenames', nargs='*', help='Filenames to fix')
+    args = parser.parse_args(argv)
+
+    pyyaml_kwargs = {
+        key: value
+        for key, value in args._get_kwargs()
+        if key != 'autofix' and key != 'filenames'
+    }
+
+    status = 0
+
+    for yaml_file in args.filenames:
+        with open(yaml_file) as f:
+            contents = f.read()
+
+        try:
+            pretty_contents = _get_pretty_format(contents, **pyyaml_kwargs)
+
+            if contents != pretty_contents:
+                print("File {0} is not pretty-formatted".format(yaml_file))
+
+                if args.autofix:
+                    _autofix(yaml_file, pretty_contents)
+
+                status = 1
+
+        except yaml.YAMLError:
+            print(
+                "Input File {0} is not a valid YAML, consider using check-yaml"
+                .format(yaml_file)
+            )
+            return 1
+
+    return status
+
+
+if __name__ == '__main__':
+    sys.exit(pretty_format_yaml(sys.argv[1:]))

setup.py

@@ -53,6 +53,7 @@ setup(
             'forbid-new-submodules = pre_commit_hooks.forbid_new_submodules:main',
             'name-tests-test = pre_commit_hooks.tests_should_end_in_test:validate_files',
             'pretty-format-json = pre_commit_hooks.pretty_format_json:pretty_format_json',
+            'pretty-format-yaml = pre_commit_hooks.pretty_format_yaml:pretty_format_yaml',
             'requirements-txt-fixer = pre_commit_hooks.requirements_txt_fixer:fix_requirements_txt',
             'trailing-whitespace-fixer = pre_commit_hooks.trailing_whitespace_fixer:fix_trailing_whitespace',
         ],

testing/resources/yaml_files/not_pretty_formatted_yaml.yaml

@@ -0,0 +1,6 @@
+foo: "bar"
+alist:
+- 2
+- 34
+- 234
+blah: null

testing/resources/yaml_files/pretty_formatted_yaml.yaml

@@ -0,0 +1,3 @@
+alist: [2, 34, 234]
+blah: null
+foo: bar

testing/resources/yaml_files/pretty_formatted_yaml_canonical_True.yaml

@@ -0,0 +1,19 @@
+---
+!!map {
+  ? !!str "array"
+  : !!seq [
+    !!int "2",
+    !!int "34",
+    !!int "234",
+  ],
+  ? !!str "null_items"
+  : !!null "null",
+  ? !!str "object"
+  : !!map {
+    ? !!str "inner_object"
+    : !!map {
+      ? !!str "attribute"
+      : !!bool "true",
+    },
+  },
+}

testing/resources/yaml_files/pretty_formatted_yaml_default_flow_style_False.yaml

@@ -0,0 +1,8 @@
+array:
+- 2
+- 34
+- 234
+null_items: null
+object:
+  inner_object:
+    attribute: true

testing/resources/yaml_files/pretty_formatted_yaml_default_style_True.yaml

@@ -0,0 +1,8 @@
+"array":
+- !!int "2"
+- !!int "34"
+- !!int "234"
+"null_items": !!null "null"
+"object":
+  "inner_object":
+    "attribute": !!bool "true"

testing/resources/yaml_files/pretty_formatted_yaml_indent_4.yaml

@@ -0,0 +1,4 @@
+array: [2, 34, 234]
+null_items: null
+object:
+    inner_object: {attribute: true}

tests/pretty_format_yaml_test.py

@@ -0,0 +1,77 @@
+import os
+import shutil
+
+import pytest
+
+from pre_commit_hooks.pretty_format_yaml import pretty_format_yaml
+from testing.util import get_resource_path
+
+
+def get_yaml_resource_path(path):
+    return get_resource_path(os.path.join('yaml_files', path))
+
+
+@pytest.mark.parametrize(('filename', 'expected_retval'), (
+    ('pretty_formatted_yaml.yaml', 0),
+    ('not_pretty_formatted_yaml.yaml', 1),
+))
+def test_pretty_format_yaml(filename, expected_retval):
+    ret = pretty_format_yaml([get_yaml_resource_path(filename)])
+    assert ret == expected_retval
+
+
+@pytest.mark.parametrize(('filename', 'arguments'), (
+    ('pretty_formatted_yaml_default_style_True.yaml', '--default_style=True'),
+    ('pretty_formatted_yaml_default_flow_style_False.yaml', '--default_flow_style=False'),
+    ('pretty_formatted_yaml_canonical_True.yaml', '--canonical=True'),
+    ('pretty_formatted_yaml_indent_4.yaml', '--indent=4'),
+))
+def test_pretty_format_yaml_arguments_success(filename, arguments):
+    assert pretty_format_yaml(arguments.split() + [get_yaml_resource_path(filename)]) == 0
+
+
+def test_autofix_pretty_format_yaml(tmpdir):
+    srcfile = tmpdir.join('to_be_yaml_formatted.yaml')
+    shutil.copyfile(
+        get_yaml_resource_path('not_pretty_formatted_yaml.yaml'),
+        srcfile.strpath,
+    )
+
+    # now launch the autofix on that file
+    ret = pretty_format_yaml(['--autofix', srcfile.strpath])
+    # it should have formatted it
+    assert ret == 1
+
+    # file was formatted (shouldn't trigger linter again)
+    ret = pretty_format_yaml([srcfile.strpath])
+    assert ret == 0
+
+
+@pytest.mark.parametrize(('argument', 'value'), (
+    ('--default_flow_style', 1),
+    ('--canonical', 'wrong_value'),
+    ('--indent', 'casual string'),
+    ('--width', 'casual string'),
+    ('--allow_unicode', 'no'),
+    ('--line_break', 'nein'),
+    ('--explicit_start', 'y'),
+    ('--explicit_end', 'n'),
+
+))
+def test_pretty_format_yaml_wrong_arguments(argument, value):
+    with pytest.raises(SystemExit):
+        pretty_format_yaml([argument + '=' + str(value), get_yaml_resource_path('pretty_formatted_yaml')])
+
+
+def test_pretty_format_yaml_invalid_yaml_file(tmpdir):
+    invalid_yaml_file = tmpdir.join('invalid.yaml')
+    with open(invalid_yaml_file.strpath, 'w') as invalid_yaml:
+        invalid_yaml.write("""
+foo: "bar"
+alist:
+2
+34
+234
+blah: null
+""")
+    assert pretty_format_yaml([invalid_yaml_file.strpath]) == 1