yamllint version 1.13.0

`-f standard` shows non-colored output,
`-f colored` shows colored output,
`-f auto` is the new default, it chooses `standard` or `colored`
depending on terminal capabilities.

.gitignore

@@ -3,3 +3,4 @@ __pycache__
 /docs/_build
 /dist
 /yamllint.egg-info
+/build

.pre-commit-hooks.yaml

@@ -1,7 +1,7 @@
 ---
 
 # For use with pre-commit.
-# See usage instructions at http://pre-commit.com
+# See usage instructions at https://pre-commit.com
 
 - id: yamllint
   name: yamllint

.travis.yml

@@ -9,16 +9,19 @@ python:
   - 3.6
   - nightly
 install:
-  - pip install pyyaml flake8 flake8-import-order coveralls sphinx
+  - pip install pyyaml flake8 flake8-import-order
   - if [[ $TRAVIS_PYTHON_VERSION == 2.6 ]]; then pip install unittest2; fi
+  - if [[ $TRAVIS_PYTHON_VERSION != 2.6 ]]; then pip install coveralls; fi
+  - if [[ $TRAVIS_PYTHON_VERSION != 2* ]]; then pip install sphinx; fi
   - pip install .
 script:
   - if [[ $TRAVIS_PYTHON_VERSION != 2.6 ]]; then flake8 .; fi
-  # Because of https://github.com/PyCQA/flake8-import-order/issues/149
-  # otherwise tests fail with Python 3.6:
-  - pip uninstall --yes enum34
   - yamllint --strict $(git ls-files '*.yaml' '*.yml')
-  - coverage run --source=yamllint setup.py test
+  - if [[ $TRAVIS_PYTHON_VERSION != 2.6 ]]; then
+      coverage run --source=yamllint setup.py test;
+    else
+      python setup.py test;
+    fi
   - if [[ $TRAVIS_PYTHON_VERSION != 2* ]]; then
       python setup.py build_sphinx;
     fi

CHANGELOG.rst

@@ -1,6 +1,34 @@
 Changelog
 =========
 
+1.13.0 (2018-11-14)
+-------------------
+
+- Use `isinstance(x, y)` instead of `type(x) == y`
+- Add a new `-f colored` option
+- Update documentation about colored output when run from CLI
+
+1.12.1 (2018-10-17)
+-------------------
+
+- Fix the `quoted-strings` rule, broken implementation
+- Fix missing documentation for the `quoted-strings` rule
+
+1.12.0 (2018-10-04)
+-------------------
+
+- Add a new `quoted-strings` rule
+- Update installation documentation for pip, CentOS, Debian, Ubuntu, Mac OS
+
+1.11.1 (2018-04-06)
+-------------------
+
+- Handle merge keys (`<<`) in the `key-duplicates` rule
+- Update documentation about pre-commit
+- Make examples for `ignore` rule clearer
+- Clarify documentation on the 'truthy' rule
+- Fix crash in parser due to a change in PyYAML > 3.12
+
 1.11.0 (2018-02-21)
 -------------------
 

README.rst

@@ -38,7 +38,8 @@ Screenshot
 Installation
 ^^^^^^^^^^^^
 
-On Fedora / CentOS:
+On Fedora / CentOS (note: `EPEL <https://fedoraproject.org/wiki/EPEL>`_ is
+required on CentOS):
 
 .. code:: bash
 
@@ -50,11 +51,17 @@ On Debian 8+ / Ubuntu 16.04+:
 
  sudo apt-get install yamllint
 
+On Mac OS 10.11+:
+
+.. code:: bash
+
+ brew install yamllint
+
 Alternatively using pip, the Python package manager:
 
 .. code:: bash
 
- sudo pip install yamllint
+ pip install --user yamllint
 
 Usage
 ^^^^^

docs/configuration.rst

@@ -102,8 +102,8 @@ Errors and warnings
 -------------------
 
 Problems detected by yamllint can be raised either as errors or as warnings.
-The CLI will output them (with different colors when using the ``standard``
-output format).
+The CLI will output them (with different colors when using the ``colored``
+output format, or ``auto`` when run from a terminal).
 
 By default the script will exit with a return code ``1`` *only when* there is one or
 more error(s).
@@ -129,7 +129,7 @@ You can either totally ignore files (they won't be looked at):
 
  ignore: |
    /this/specific/file.yaml
-   /all/this/directory/
+   all/this/directory/
    *.template.yaml
 
 or ignore paths only for specific rules:
@@ -167,4 +167,4 @@ Here is a more complex example:
    trailing-spaces:
      ignore: |
        *.ignore-trailing-spaces.yaml
-       /ascii-art/*
+       ascii-art/*

docs/quickstart.rst

@@ -16,25 +16,24 @@ On Debian 8+ / Ubuntu 16.04+:
 
  sudo apt-get install yamllint
 
-On older Debian / Ubuntu versions:
+On Mac OS 10.11+:
 
 .. code:: bash
 
- sudo add-apt-repository -y ppa:adrienverge/ppa && sudo apt-get update
- sudo apt-get install yamllint
+ brew install yamllint
 
 Alternatively using pip, the Python package manager:
 
 .. code:: bash
 
- sudo pip install yamllint
+ pip install --user yamllint
 
 If you prefer installing from source, you can run, from the source directory:
 
 .. code:: bash
 
  python setup.py sdist
- sudo pip install dist/yamllint-*.tar.gz
+ pip install --user dist/yamllint-*.tar.gz
 
 Running yamllint
 ----------------
@@ -69,6 +68,10 @@ The output will look like (colors are not displayed here):
    10:1      error    too many blank lines (4 > 2)  (empty-lines)
    11:4      error    too many spaces inside braces  (braces)
 
+By default, the output of yamllint is colored when run from a terminal, and pure
+text in other cases. Add the ``-f standard`` arguments to force non-colored output.
+Use the ``-f colored`` arguments to force colored output.
+
 Add the ``-f parsable`` arguments if you need an output format parsable by a
 machine (for instance for :doc:`syntax highlighting in text editors
 <text_editors>`). The output will then look like:

docs/rules.rst

@@ -104,6 +104,11 @@ octal-values
 
 .. automodule:: yamllint.rules.octal_values
 
+quoted-strings
+--------------
+
+.. automodule:: yamllint.rules.quoted_strings
+
 trailing-spaces
 ---------------
 

tests/rules/test_key_duplicates.py

@@ -78,6 +78,15 @@ class KeyDuplicatesTestCase(RuleTestCase):
                    '    duplicates with\n'
                    '    many styles\n'
                    ': 1\n', conf)
+        self.check('---\n'
+                   'Merge Keys are OK:\n'
+                   'anchor_one: &anchor_one\n'
+                   '  one: one\n'
+                   'anchor_two: &anchor_two\n'
+                   '  two: two\n'
+                   'anchor_reference:\n'
+                   '  <<: *anchor_one\n'
+                   '  <<: *anchor_two\n', conf)
 
     def test_enabled(self):
         conf = 'key-duplicates: enable'
@@ -147,6 +156,15 @@ class KeyDuplicatesTestCase(RuleTestCase):
                    ': 1\n', conf,
                    problem1=(3, 1), problem2=(4, 1), problem3=(5, 3),
                    problem4=(7, 3))
+        self.check('---\n'
+                   'Merge Keys are OK:\n'
+                   'anchor_one: &anchor_one\n'
+                   '  one: one\n'
+                   'anchor_two: &anchor_two\n'
+                   '  two: two\n'
+                   'anchor_reference:\n'
+                   '  <<: *anchor_one\n'
+                   '  <<: *anchor_two\n', conf)
 
     def test_key_tokens_in_flow_sequences(self):
         conf = 'key-duplicates: enable'

tests/rules/test_quoted_strings.py

@@ -0,0 +1,125 @@
+# -*- coding: utf-8 -*-
+# Copyright (C) 2018 ClearScore
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from tests.common import RuleTestCase
+
+
+class QuotedTestCase(RuleTestCase):
+    rule_id = 'quoted-strings'
+
+    def test_disabled(self):
+        conf = 'quoted-strings: disable'
+        self.check('---\n'
+                   'foo: bar\n', conf)
+        self.check('---\n'
+                   'foo: "bar"\n', conf)
+        self.check('---\n'
+                   'foo: \'bar\'\n', conf)
+        self.check('---\n'
+                   'bar: 123\n', conf)
+
+    def test_quote_type_any(self):
+        conf = 'quoted-strings: {quote-type: any}\n'
+        self.check('---\n'
+                   'boolean1: true\n'
+                   'number1: 123\n'
+                   'string1: foo\n'                          # fails
+                   'string2: "foo"\n'
+                   'string3: \'bar\'\n'
+                   'string4: !!str genericstring\n'
+                   'string5: !!str 456\n'
+                   'string6: !!str "quotedgenericstring"\n'
+                   'binary: !!binary binstring\n'
+                   'integer: !!int intstring\n'
+                   'boolean2: !!bool boolstring\n'
+                   'boolean3: !!bool "quotedboolstring"\n',
+                   conf, problem=(4, 10))
+        self.check('---\n'
+                   'multiline string 1: |\n'
+                   '  line 1\n'
+                   '  line 2\n'
+                   'multiline string 2: >\n'
+                   '  word 1\n'
+                   '  word 2\n'
+                   'multiline string 3:\n'
+                   '  word 1\n'
+                   '  word 2\n'
+                   'multiline string 4:\n'
+                   '  "word 1\\\n'
+                   '   word 2"\n',
+                   conf, problem1=(9, 3))
+
+    def test_quote_type_single(self):
+        conf = 'quoted-strings: {quote-type: single}\n'
+        self.check('---\n'
+                   'boolean1: true\n'
+                   'number1: 123\n'
+                   'string1: foo\n'                          # fails
+                   'string2: "foo"\n'                        # fails
+                   'string3: \'bar\'\n'
+                   'string4: !!str genericstring\n'
+                   'string5: !!str 456\n'
+                   'string6: !!str "quotedgenericstring"\n'
+                   'binary: !!binary binstring\n'
+                   'integer: !!int intstring\n'
+                   'boolean2: !!bool boolstring\n'
+                   'boolean3: !!bool "quotedboolstring"\n',
+                   conf, problem1=(4, 10), problem2=(5, 10))
+        self.check('---\n'
+                   'multiline string 1: |\n'
+                   '  line 1\n'
+                   '  line 2\n'
+                   'multiline string 2: >\n'
+                   '  word 1\n'
+                   '  word 2\n'
+                   'multiline string 3:\n'
+                   '  word 1\n'
+                   '  word 2\n'
+                   'multiline string 4:\n'
+                   '  "word 1\\\n'
+                   '   word 2"\n',
+                   conf, problem1=(9, 3), problem2=(12, 3))
+
+    def test_quote_type_double(self):
+        conf = 'quoted-strings: {quote-type: double}\n'
+        self.check('---\n'
+                   'boolean1: true\n'
+                   'number1: 123\n'
+                   'string1: foo\n'                          # fails
+                   'string2: "foo"\n'
+                   'string3: \'bar\'\n'                      # fails
+                   'string4: !!str genericstring\n'
+                   'string5: !!str 456\n'
+                   'string6: !!str "quotedgenericstring"\n'
+                   'binary: !!binary binstring\n'
+                   'integer: !!int intstring\n'
+                   'boolean2: !!bool boolstring\n'
+                   'boolean3: !!bool "quotedboolstring"\n',
+                   conf, problem1=(4, 10), problem2=(6, 10))
+        self.check('---\n'
+                   'multiline string 1: |\n'
+                   '  line 1\n'
+                   '  line 2\n'
+                   'multiline string 2: >\n'
+                   '  word 1\n'
+                   '  word 2\n'
+                   'multiline string 3:\n'
+                   '  word 1\n'
+                   '  word 2\n'
+                   'multiline string 4:\n'
+                   '  "word 1\\\n'
+                   '   word 2"\n',
+                   conf, problem1=(9, 3))

tests/test_cli.py

@@ -351,7 +351,7 @@ class CommandLineTestCase(unittest.TestCase):
             '\n' % file))
         self.assertEqual(err, '')
 
-    def test_run_colored_output(self):
+    def test_run_default_format_output_in_tty(self):
         file = os.path.join(self.wd, 'a.yaml')
 
         # Create a pseudo-TTY and redirect stdout to it
@@ -383,3 +383,59 @@ class CommandLineTestCase(unittest.TestCase):
             'no new line character at the end of file  '
             '\033[2m(new-line-at-end-of-file)\033[0m\n'
             '\n' % file))
+
+    def test_run_default_format_output_without_tty(self):
+        file = os.path.join(self.wd, 'a.yaml')
+
+        sys.stdout, sys.stderr = StringIO(), StringIO()
+        with self.assertRaises(SystemExit) as ctx:
+            cli.run((file, ))
+
+        self.assertEqual(ctx.exception.code, 1)
+
+        out, err = sys.stdout.getvalue(), sys.stderr.getvalue()
+        self.assertEqual(out, (
+            '%s\n'
+            '  2:4       error    trailing spaces  (trailing-spaces)\n'
+            '  3:4       error    no new line character at the end of file  '
+            '(new-line-at-end-of-file)\n'
+            '\n' % file))
+        self.assertEqual(err, '')
+
+    def test_run_auto_output_without_tty_output(self):
+        file = os.path.join(self.wd, 'a.yaml')
+
+        sys.stdout, sys.stderr = StringIO(), StringIO()
+        with self.assertRaises(SystemExit) as ctx:
+            cli.run((file, '--format', 'auto'))
+
+        self.assertEqual(ctx.exception.code, 1)
+
+        out, err = sys.stdout.getvalue(), sys.stderr.getvalue()
+        self.assertEqual(out, (
+            '%s\n'
+            '  2:4       error    trailing spaces  (trailing-spaces)\n'
+            '  3:4       error    no new line character at the end of file  '
+            '(new-line-at-end-of-file)\n'
+            '\n' % file))
+        self.assertEqual(err, '')
+
+    def test_run_format_colored(self):
+        file = os.path.join(self.wd, 'a.yaml')
+
+        sys.stdout, sys.stderr = StringIO(), StringIO()
+        with self.assertRaises(SystemExit) as ctx:
+            cli.run((file, '--format', 'colored'))
+
+        self.assertEqual(ctx.exception.code, 1)
+
+        out, err = sys.stdout.getvalue(), sys.stderr.getvalue()
+        self.assertEqual(out, (
+            '\033[4m%s\033[0m\n'
+            '  \033[2m2:4\033[0m       \033[31merror\033[0m    '
+            'trailing spaces  \033[2m(trailing-spaces)\033[0m\n'
+            '  \033[2m3:4\033[0m       \033[31merror\033[0m    '
+            'no new line character at the end of file  '
+            '\033[2m(new-line-at-end-of-file)\033[0m\n'
+            '\n' % file))
+        self.assertEqual(err, '')

yamllint/__init__.py

@@ -22,7 +22,7 @@ indentation, etc."""
 
 
 APP_NAME = 'yamllint'
-APP_VERSION = '1.11.0'
+APP_VERSION = '1.13.0'
 APP_DESCRIPTION = __doc__
 
 __author__ = u'Adrien Vergé'

yamllint/cli.py

@@ -96,8 +96,8 @@ def run(argv=None):
                               action='store',
                               help='custom configuration (as YAML source)')
     parser.add_argument('-f', '--format',
-                        choices=('parsable', 'standard'), default='standard',
-                        help='format for parsing output')
+                        choices=('parsable', 'standard', 'colored', 'auto'),
+                        default='auto', help='format for parsing output')
     parser.add_argument('-s', '--strict',
                         action='store_true',
                         help='return non-zero exit code on warnings '
@@ -143,7 +143,8 @@ def run(argv=None):
                 for problem in linter.run(f, conf, filepath):
                     if args.format == 'parsable':
                         print(Format.parsable(problem, file))
-                    elif supports_color():
+                    elif args.format == 'colored' or \
+                            (args.format == 'auto' and supports_color()):
                         if first:
                             print('\033[4m%s\033[0m' % file)
                             first = False

yamllint/conf/default.yaml

@@ -32,6 +32,7 @@ rules:
     max: 2
     max-start: 0
     max-end: 0
+  quoted-strings: disable
   empty-values:
     forbid-in-block-mappings: false
     forbid-in-flow-mappings: false

yamllint/config.py

@@ -52,7 +52,7 @@ class YamlLintConfig(object):
         assert isinstance(base_config, YamlLintConfig)
 
         for rule in self.rules:
-            if (type(self.rules[rule]) == dict and
+            if (isinstance(self.rules[rule], dict) and
                     rule in base_config.rules and
                     base_config.rules[rule] is not False):
                 base_config.rules[rule].update(self.rules[rule])
@@ -70,7 +70,7 @@ class YamlLintConfig(object):
         except Exception as e:
             raise YamlLintConfigError('invalid config: %s' % e)
 
-        if type(conf) != dict:
+        if not isinstance(conf, dict):
             raise YamlLintConfigError('invalid config: not a dict')
 
         self.rules = conf.get('rules', {})
@@ -85,7 +85,7 @@ class YamlLintConfig(object):
                 raise YamlLintConfigError('invalid config: %s' % e)
 
         if 'ignore' in conf:
-            if type(conf['ignore']) != str:
+            if not isinstance(conf['ignore'], str):
                 raise YamlLintConfigError(
                     'invalid config: ignore should contain file patterns')
             self.ignore = pathspec.PathSpec.from_lines(
@@ -107,10 +107,10 @@ def validate_rule_conf(rule, conf):
     elif conf == 'enable':
         conf = {}
 
-    if type(conf) == dict:
+    if isinstance(conf, dict):
         if ('ignore' in conf and
-                type(conf['ignore']) != pathspec.pathspec.PathSpec):
-            if type(conf['ignore']) != str:
+                not isinstance(conf['ignore'], pathspec.pathspec.PathSpec)):
+            if not isinstance(conf['ignore'], str):
                 raise YamlLintConfigError(
                     'invalid config: ignore should contain file patterns')
             conf['ignore'] = pathspec.PathSpec.from_lines(
@@ -130,14 +130,14 @@ def validate_rule_conf(rule, conf):
                 raise YamlLintConfigError(
                     'invalid config: unknown option "%s" for rule "%s"' %
                     (optkey, rule.ID))
-            if type(options[optkey]) == tuple:
+            if isinstance(options[optkey], tuple):
                 if (conf[optkey] not in options[optkey] and
                         type(conf[optkey]) not in options[optkey]):
                     raise YamlLintConfigError(
                         'invalid config: option "%s" of "%s" should be in %s'
                         % (optkey, rule.ID, options[optkey]))
             else:
-                if type(conf[optkey]) != options[optkey]:
+                if not isinstance(conf[optkey], options[optkey]):
                     raise YamlLintConfigError(
                         'invalid config: option "%s" of "%s" should be %s'
                         % (optkey, rule.ID, options[optkey].__name__))

yamllint/linter.py

@@ -226,7 +226,7 @@ def run(input, conf, filepath=None):
     if conf.is_file_ignored(filepath):
         return ()
 
-    if type(input) in (type(b''), type(u'')):  # compat with Python 2 & 3
+    if isinstance(input, (type(b''), type(u''))):  # compat with Python 2 & 3
         return _run(input, conf, filepath)
     elif hasattr(input, 'read'):  # Python 2's file or Python 3's io.IOBase
         # We need to have everything in memory to parse correctly

yamllint/parser.py

@@ -125,7 +125,8 @@ def token_or_comment_generator(buffer):
         curr = yaml_loader.get_token()
         while curr is not None:
             next = yaml_loader.get_token()
-            nextnext = yaml_loader.peek_token()
+            nextnext = (yaml_loader.peek_token()
+                        if yaml_loader.check_token() else None)
 
             yield Token(curr.start_mark.line + 1, curr, prev, next, nextnext)
 

yamllint/rules/__init__.py

@@ -33,6 +33,7 @@ from yamllint.rules import (
     new_line_at_end_of_file,
     new_lines,
     octal_values,
+    quoted_strings,
     trailing_spaces,
     truthy,
 )
@@ -56,6 +57,7 @@ _RULES = {
     new_line_at_end_of_file.ID: new_line_at_end_of_file,
     new_lines.ID: new_lines,
     octal_values.ID: octal_values,
+    quoted_strings.ID: quoted_strings,
     trailing_spaces.ID: trailing_spaces,
     truthy.ID: truthy,
 }

yamllint/rules/document_end.py

@@ -86,14 +86,16 @@ CONF = {'present': bool}
 
 def check(conf, token, prev, next, nextnext, context):
     if conf['present']:
-        if (isinstance(token, yaml.StreamEndToken) and
-                not (isinstance(prev, yaml.DocumentEndToken) or
-                     isinstance(prev, yaml.StreamStartToken))):
+        is_stream_end = isinstance(token, yaml.StreamEndToken)
+        is_start = isinstance(token, yaml.DocumentStartToken)
+        prev_is_end_or_stream_start = isinstance(
+            prev, (yaml.DocumentEndToken, yaml.StreamStartToken)
+        )
+
+        if is_stream_end and not prev_is_end_or_stream_start:
             yield LintProblem(token.start_mark.line, 1,
                               'missing document end "..."')
-        elif (isinstance(token, yaml.DocumentStartToken) and
-                not (isinstance(prev, yaml.DocumentEndToken) or
-                     isinstance(prev, yaml.StreamStartToken))):
+        elif is_start and not prev_is_end_or_stream_start:
             yield LintProblem(token.start_mark.line + 1, 1,
                               'missing document end "..."')
 

yamllint/rules/indentation.py

@@ -224,7 +224,7 @@ def check_scalar_indentation(conf, token, context):
 
     def compute_expected_indent(found_indent):
         def detect_indent(base_indent):
-            if type(context['spaces']) is not int:
+            if not isinstance(context['spaces'], int):
                 context['spaces'] = found_indent - base_indent
             return base_indent + context['spaces']
 
@@ -312,7 +312,7 @@ def _check(conf, token, prev, next, nextnext, context):
                      token.start_mark.line + 1 > context['cur_line'])
 
     def detect_indent(base_indent, next):
-        if type(context['spaces']) is not int:
+        if not isinstance(context['spaces'], int):
             context['spaces'] = next.start_mark.column - base_indent
         return base_indent + context['spaces']
 

yamllint/rules/key_duplicates.py

@@ -91,7 +91,9 @@ def check(conf, token, prev, next, nextnext, context):
         # This check is done because KeyTokens can be found inside flow
         # sequences... strange, but allowed.
         if len(context['stack']) > 0 and context['stack'][-1].type == MAP:
-            if next.value in context['stack'][-1].keys:
+            if (next.value in context['stack'][-1].keys and
+                    # `<<` is "merge key", see http://yaml.org/type/merge.html
+                    next.value != '<<'):
                 yield LintProblem(
                     next.start_mark.line + 1, next.start_mark.column + 1,
                     'duplication of key "%s" in mapping' % next.value)

yamllint/rules/quoted_strings.py

@@ -0,0 +1,77 @@
+# -*- coding: utf-8 -*-
+# Copyright (C) 2018 ClearScore
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
+Use this rule to forbid any string values that are not quoted.
+You can also enforce the type of the quote used using the ``quote-type`` option
+(``single``, ``double`` or ``any``).
+
+**Note**: Multi-line strings (with ``|`` or ``>``) will not be checked.
+
+.. rubric:: Examples
+
+#. With ``quoted-strings: {quote-type: any}``
+
+   the following code snippet would **PASS**:
+   ::
+
+    foo: "bar"
+    bar: 'foo'
+    number: 123
+    boolean: true
+
+   the following code snippet would **FAIL**:
+   ::
+
+    foo: bar
+"""
+
+import yaml
+
+from yamllint.linter import LintProblem
+
+ID = 'quoted-strings'
+TYPE = 'token'
+CONF = {'quote-type': ('any', 'single', 'double')}
+
+
+def check(conf, token, prev, next, nextnext, context):
+    quote_type = conf['quote-type']
+
+    if (isinstance(token, yaml.tokens.ScalarToken) and
+            isinstance(prev, (yaml.ValueToken, yaml.TagToken))):
+        # Ignore explicit types, e.g. !!str testtest or !!int 42
+        if (prev and isinstance(prev, yaml.tokens.TagToken) and
+                prev.value[0] == '!!'):
+            return
+
+        # Ignore numbers, booleans, etc.
+        resolver = yaml.resolver.Resolver()
+        if resolver.resolve(yaml.nodes.ScalarNode, token.value,
+                            (True, False)) != 'tag:yaml.org,2002:str':
+            return
+
+        # Ignore multi-line strings
+        if (not token.plain) and (token.style == "|" or token.style == ">"):
+            return
+
+        if ((quote_type == 'single' and token.style != "'") or
+                (quote_type == 'double' and token.style != '"') or
+                (quote_type == 'any' and token.style is None)):
+            yield LintProblem(
+                token.start_mark.line + 1,
+                token.start_mark.column + 1,
+                "string value is not quoted with %s quotes" % (quote_type))

yamllint/rules/truthy.py

@@ -15,11 +15,12 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 """
-Use this rule to forbid truthy values that are not quoted nor explicitly typed.
+Use this rule to forbid non-explictly typed truthy values other than ``true``
+and ``false``, for example ``YES``, ``False`` and ``off``.
 
-This would prevent YAML parsers from transforming ``[yes, FALSE, Off]`` into
-``[true, false, false]`` or ``{y: 1, yes: 2, on: 3, true: 4, True: 5}`` into
-``{y: 1, true: 5}``.
+This can be useful to prevent surprises from YAML parsers transforming
+``[yes, FALSE, Off]`` into ``[true, false, false]`` or
+``{y: 1, yes: 2, on: 3, true: 4, True: 5}`` into ``{y: 1, true: 5}``.
 
 .. rubric:: Examples
 
@@ -34,8 +35,7 @@ This would prevent YAML parsers from transforming ``[yes, FALSE, Off]`` into
 
     "yes":  1
     "on":   2
-    "true": 3
-    "True": 4
+    "True": 3
 
      explicit:
        string1: !!str True
@@ -62,8 +62,7 @@ This would prevent YAML parsers from transforming ``[yes, FALSE, Off]`` into
 
     yes:  1
     on:   2
-    true: 3
-    True: 4
+    True: 3
 """
 
 import yaml
@@ -90,4 +89,4 @@ def check(conf, token, prev, next, nextnext, context):
         if token.value in TRUTHY and token.style is None:
             yield LintProblem(token.start_mark.line + 1,
                               token.start_mark.column + 1,
-                              "truthy value is not quoted")
+                              "truthy value should be true or false")