yamllint version 1.31.0

Using `setup.py` is deprecated and the new recommanded way is to declare
a `pyproject.toml` file (see PEP 517 [^1]).

This commit proposes to use setuptools to achieve that, because
setuptools is already used by yamllint, is standard and referenced by
the official Python packaging documentation [^2], and seems to be the
most lightweight solution. An alternative could have been to use Poetry,
see the dedicated pull request and discussion [^3].

For some period, the `setup.py` file will be kept (although almost
empty), to allow old tools versions to keep working.

Closes https://github.com/adrienverge/yamllint/issues/509.

[^1]: https://peps.python.org/pep-0517/
[^2]: https://packaging.python.org/en/latest/tutorials/installing-packages/
[^3]: https://github.com/adrienverge/yamllint/pull/557

.flake8

@@ -0,0 +1,4 @@
+[flake8]
+import-order-style = pep8
+application-import-names = yamllint
+ignore = W503,W504

.github/workflows/ci.yaml

@@ -8,24 +8,28 @@ on:  # yamllint disable-line rule:truthy
     branches:
       - master
 
+permissions:
+  contents: read
+
 jobs:
   lint:
     name: Linters
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
       - name: Set up Python
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v4
       - run:
-          python -m pip install flake8 flake8-import-order doc8 sphinx
-            rstcheck[sphinx]
-      - run: python -m pip install .
+          pip install flake8 flake8-import-order sphinx rstcheck[sphinx] doc8
+      - run: pip install .
       - run: flake8 .
       - run: doc8 $(git ls-files '*.rst')
       - run: rstcheck --ignore-directives automodule $(git ls-files '*.rst')
       - run: yamllint --strict $(git ls-files '*.yaml' '*.yml')
-      - run: python setup.py build_sphinx
+      - run: make -C docs html
+      - name: Check for broken links in documentation
+        run: make -C docs linkcheck
 
   test:
     name: Tests
@@ -34,22 +38,24 @@ jobs:
       fail-fast: false
       matrix:
         python-version:
-          - '3.6'
           - '3.7'
           - '3.8'
           - '3.9'
           - '3.10'
+          - '3.11'
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.python-version }}
       - name: Append GitHub Actions system path
         run: echo "$HOME/.local/bin" >> $GITHUB_PATH
-      - run: pip install coveralls
+      - run: pip install coverage
       - run: pip install .
-      - run: coverage run --source=yamllint -m unittest discover
+      # https://github.com/AndreMiras/coveralls-python-action/issues/18
+      - run: echo -e "[run]\nrelative_files = True" > .coveragerc
+      - run: coverage run -m unittest discover
       - name: Coveralls
         uses: AndreMiras/coveralls-python-action@develop

CHANGELOG.rst

@@ -1,6 +1,35 @@
 Changelog
 =========
 
+1.31.0 (2023-04-21)
+-------------------
+
+- Build: migrate from ``setup.py`` to ``pyproject.toml``
+- Docs: update some outdated URLs
+- Rule ``colons``: prevent error when space before is mandatory
+
+1.30.0 (2023-03-22)
+-------------------
+
+- Rule ``anchors``: add new rule to detect undeclared or duplicated anchors
+- Python API: prevent using ``is_file_ignored()`` with null ``filepath``
+- Docs: fix misleading Python API example
+- Docs: fix plain text code snippet example
+- Docs: update pre-commit hook example
+
+1.29.0 (2023-01-10)
+-------------------
+
+- Add support for Python 3.11, drop support for Python 3.6
+- Rule ``float-values``: fix bug on strings containing fordidden values
+- Stop releasing universal wheels
+- Use proper Python 3 I/O type for file reading
+- Rule ``indentation``: fix ``indent-sequences`` in nested collections
+- Docs: clarify ``disable-line`` and parser errors, give a workaround
+- Refactors to apply some pyupgrade suggestions
+- Allow using a list of strings in ``ignore`` configuration
+- Add ``--list-files`` command line option
+
 1.28.0 (2022-09-12)
 -------------------
 

MANIFEST.in

@@ -1,4 +0,0 @@
-include LICENSE
-include README.rst
-include docs/*
-include tests/*.py tests/rules/*.py tests/yaml-1.2-spec-examples/*

README.rst

@@ -8,8 +8,8 @@ repetition and cosmetic problems such as lines length, trailing spaces,
 indentation, etc.
 
 .. image::
-   https://travis-ci.org/adrienverge/yamllint.svg?branch=master
-   :target: https://travis-ci.org/adrienverge/yamllint
+   https://github.com/adrienverge/yamllint/actions/workflows/ci.yaml/badge.svg?branch=master
+   :target: https://github.com/adrienverge/yamllint/actions/workflows/ci.yaml?query=branch%3Amaster
    :alt: CI tests status
 .. image::
    https://coveralls.io/repos/github/adrienverge/yamllint/badge.svg?branch=master

docs/Makefile

@@ -2,7 +2,7 @@
 #
 
 # You can set these variables from the command line.
-SPHINXOPTS    =
+SPHINXOPTS    = -W
 SPHINXBUILD   = sphinx-build
 PAPER         =
 BUILDDIR      = _build

docs/conf.py

@@ -38,7 +38,7 @@ htmlhelp_basename = 'yamllintdoc'
 # One entry per manual page. List of tuples
 # (source start file, name, description, authors, manual section).
 man_pages = [
-    ('index', 'yamllint', 'Linter for YAML files', [u'Adrien Vergé'], 1)
+    ('index', 'yamllint', 'Linter for YAML files', ['Adrien Vergé'], 1)
 ]
 
 # -- Build with sphinx automodule without needing to install third-party libs

docs/configuration.rst

@@ -136,11 +136,19 @@ directories, set ``yaml-files`` configuration option. The default is:
 The same rules as for ignoring paths apply (``.gitignore``-style path pattern,
 see below).
 
+If you need to know the exact list of files that yamllint would process,
+without really linting them, you can use ``--list-files``:
+
+.. code:: bash
+
+ yamllint --list-files .
+
 Ignoring paths
 --------------
 
 It is possible to exclude specific files or directories, so that the linter
-doesn't process them.
+doesn't process them. They can be provided either as a list of paths, or as a
+bulk string.
 
 You can either totally ignore files (they won't be looked at):
 
@@ -153,6 +161,13 @@ You can either totally ignore files (they won't be looked at):
    all/this/directory/
    *.template.yaml
 
+ # or:
+
+ ignore:
+   - /this/specific/file.yaml
+   - all/this/directory/
+   - '*.template.yaml'
+
 or ignore paths only for specific rules:
 
 .. code-block:: yaml
@@ -165,10 +180,18 @@ or ignore paths only for specific rules:
        /this-file-has-trailing-spaces-but-it-is-OK.yaml
        /generated/*.yaml
 
+ # or:
+
+ rules:
+   trailing-spaces:
+     ignore:
+       - /this-file-has-trailing-spaces-but-it-is-OK.yaml
+       - /generated/*.yaml
+
 Note that this ``.gitignore``-style path pattern allows complex path
 exclusion/inclusion, see the `pathspec README file
-<https://pypi.python.org/pypi/pathspec>`_ for more details.
-Here is a more complex example:
+<https://pypi.org/project/pathspec/>`_ for more details. Here is a more complex
+example:
 
 .. code-block:: yaml
 
@@ -204,6 +227,13 @@ or:
 
 .. note:: However, this is mutually exclusive with the ``ignore`` key.
 
+If you need to know the exact list of files that yamllint would process,
+without really linting them, you can use ``--list-files``:
+
+.. code:: bash
+
+ yamllint --list-files .
+
 Setting the locale
 ------------------
 

docs/development.rst

@@ -11,7 +11,7 @@ Basic example of running the linter from Python:
    import yamllint
 
    yaml_config = yamllint.config.YamlLintConfig("extends: default")
-   for p in yamllint.linter.run("example.yaml", yaml_config):
+   for p in yamllint.linter.run(open("example.yaml", "r"), yaml_config):
        print(p.desc, p.line, p.rule)
 
 .. automodule:: yamllint.linter

docs/disable_with_comments.rst

@@ -40,6 +40,11 @@ specific line:
  # yamllint disable-line
  -  {    all : rules ,are disabled   for this line}
 
+You can't make yamllint ignore invalid YAML syntax on a line (which generates a
+`syntax error`), such as when templating a YAML file with Jinja. In some cases,
+you can workaround this by putting the templating syntax in a YAML comment. See
+`Putting template flow control in comments`_.
+
 If you need to disable multiple rules, it is allowed to chain rules like this:
 ``# yamllint disable-line rule:hyphens rule:commas rule:indentation``.
 
@@ -89,7 +94,6 @@ For instance:
  key: value 2
 
  - This line is waaaaaaaaaay too long but yamllint will not report anything about it.
-   This line will be checked by yamllint.
 
 or:
 
@@ -101,3 +105,32 @@ or:
  key1: value1
  {% endif %}
  key2: value2
+
+Putting template flow control in comments
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Alternatively for templating you can wrap the template statements in comments
+to make it a valid YAML file. As long as the templating language doesn't use
+the same comment symbol, it should be a valid template and valid YAML (pre and
+post-template processing).
+
+Example of a Jinja2 code that cannot be parsed as YAML because it contains
+invalid tokens ``{%`` and ``%}``:
+
+.. code-block:: text
+
+ # This file IS NOT valid YAML and will produce syntax errors
+ {% if extra_info %}
+ key1: value1
+ {% endif %}
+ key2: value2
+
+But it can be fixed using YAML comments:
+
+.. code-block:: yaml
+
+ # This file IS valid YAML because the Jinja is in a YAML comment
+ # {% if extra_info %}
+ key1: value1
+ # {% endif %}
+ key2: value2

docs/index.rst

@@ -11,7 +11,7 @@ Screenshot
 
 .. note::
 
-   The default output format is inspired by `eslint <http://eslint.org/>`_, a
+   The default output format is inspired by `eslint <https://eslint.org/>`_, a
    great linting tool for Javascript.
 
 Table of contents

docs/integration.rst

@@ -4,7 +4,7 @@ Integration with other software
 Integration with pre-commit
 ---------------------------
 
-You can integrate yamllint in `pre-commit <http://pre-commit.com/>`_ tool.
+You can integrate yamllint in the `pre-commit <https://pre-commit.com/>`_ tool.
 Here is an example, to add in your .pre-commit-config.yaml
 
 .. code:: yaml
@@ -12,11 +12,13 @@ Here is an example, to add in your .pre-commit-config.yaml
   ---
   # Update the rev variable with the release version that you want, from the yamllint repo
   # You can pass your custom .yamllint with args attribute.
-  - repo: https://github.com/adrienverge/yamllint.git
-    rev: v1.17.0
-    hooks:
-      - id: yamllint
-        args: [-c=/path/to/.yamllint]
+  repos:
+    - repo: https://github.com/adrienverge/yamllint.git
+      rev: v1.29.0
+      hooks:
+        - id: yamllint
+          args: [--strict, -c=/path/to/.yamllint]
+
 
 Integration with GitHub Actions
 -------------------------------
@@ -26,7 +28,7 @@ Actions <https://github.com/features/actions>`_ and automatically uses the
 suited output format to decorate code with linting errors. You can also force
 the GitHub Actions output with ``yamllint --format github``.
 
-An minimal example workflow using GitHub Actions:
+A minimal example workflow using GitHub Actions:
 
 .. code:: yaml
 

docs/quickstart.rst

@@ -4,7 +4,7 @@ Quickstart
 Installing yamllint
 -------------------
 
-On Fedora / CentOS (note: `EPEL <https://fedoraproject.org/wiki/EPEL>`_ is
+On Fedora / CentOS (note: `EPEL <https://docs.fedoraproject.org/en-US/epel/>`_ is
 required on CentOS):
 
 .. code:: bash
@@ -45,7 +45,7 @@ If you prefer installing from source, you can run, from the source directory:
 
 .. code:: bash
 
- python setup.py sdist
+ python -m build
  pip install --user dist/yamllint-*.tar.gz
 
 Running yamllint

docs/rules.rst

@@ -14,6 +14,11 @@ This page describes the rules and their options.
    :local:
    :depth: 1
 
+anchors
+-------
+
+.. automodule:: yamllint.rules.anchors
+
 braces
 ------
 

docs/text_editors.rst

@@ -13,7 +13,7 @@ Assuming that the `ALE <https://github.com/dense-analysis/ale>`_ plugin is
 installed, yamllint is supported by default. It is automatically enabled when
 editing YAML files.
 
-If you instead use the `syntastic <https://github.com/scrooloose/syntastic>`_
+If you instead use the `syntastic <https://github.com/vim-syntastic/syntastic>`_
 plugin, add this to your ``.vimrc``:
 
 ::
@@ -23,7 +23,7 @@ plugin, add this to your ``.vimrc``:
 Neovim
 ------
 
-Assuming that the `neomake <https://github.com/benekastah/neomake>`_ plugin is
+Assuming that the `neomake <https://github.com/neomake/neomake>`_ plugin is
 installed, yamllint is supported by default. It is automatically enabled when
 editing YAML files.
 

pyproject.toml

@@ -0,0 +1,54 @@
+[project]
+name = "yamllint"
+description = "A linter for YAML files."
+readme = {file = "README.rst", content-type = "text/x-rst"}
+requires-python = ">=3.7"
+license = {text = "GPL-3.0-only"}
+authors = [{name = "Adrien Vergé"}]
+keywords = ["yaml", "lint", "linter", "syntax", "checker"]
+classifiers = [
+    "Development Status :: 5 - Production/Stable",
+    "Environment :: Console",
+    "Intended Audience :: Developers",
+    "License :: OSI Approved :: GNU General Public License v3 (GPLv3)",
+    "Programming Language :: Python",
+    "Topic :: Software Development",
+    "Topic :: Software Development :: Debuggers",
+    "Topic :: Software Development :: Quality Assurance",
+    "Topic :: Software Development :: Testing",
+]
+dependencies = [
+    "pathspec >= 0.5.3",
+    "pyyaml",
+]
+dynamic = ["version"]
+
+[project.optional-dependencies]
+dev = [
+    "doc8",
+    "flake8",
+    "flake8-import-order",
+    "rstcheck[sphinx]",
+    "sphinx",
+]
+
+[project.scripts]
+yamllint = "yamllint.cli:run"
+
+[project.urls]
+homepage = "https://github.com/adrienverge/yamllint"
+repository = "https://github.com/adrienverge/yamllint"
+documentation = "https://yamllint.readthedocs.io"
+
+[build-system]
+build-backend = "setuptools.build_meta"
+requires = ["setuptools >= 61"]
+
+[tool.setuptools]
+packages = ["yamllint", "yamllint.conf", "yamllint.rules"]
+
+[tool.setuptools.package-data]
+yamllint = ["conf/*.yaml"]
+
+[tool.setuptools.dynamic]
+version = {attr = "yamllint.__version__"}

setup.cfg

@@ -1,72 +0,0 @@
-[bdist_wheel]
-universal = 1
-
-[flake8]
-import-order-style = pep8
-application-import-names = yamllint
-ignore = W503,W504
-
-[build_sphinx]
-all-files = 1
-source-dir = docs
-build-dir = docs/_build
-warning-is-error = 1
-
-[metadata]
-keywords =
-  yaml
-  lint
-  linter
-  syntax
-  checker
-
-url = https://github.com/adrienverge/yamllint
-classifiers =
-  Development Status :: 5 - Production/Stable
-  Environment :: Console
-  Intended Audience :: Developers
-  License :: OSI Approved :: GNU General Public License v3 (GPLv3)
-  Programming Language :: Python :: 3
-  Programming Language :: Python :: 3.6
-  Programming Language :: Python :: 3.7
-  Programming Language :: Python :: 3.8
-  Programming Language :: Python :: 3.9
-  Programming Language :: Python :: 3.10
-  Topic :: Software Development
-  Topic :: Software Development :: Debuggers
-  Topic :: Software Development :: Quality Assurance
-  Topic :: Software Development :: Testing
-
-project_urls =
-  Documentation = https://yamllint.readthedocs.io
-  Download = https://pypi.org/project/yamllint/#files
-  Bug Tracker = https://github.com/adrienverge/yamllint/issues
-  Source Code = https://github.com/adrienverge/yamllint
-
-[options]
-packages = find:
-
-python_requires = >=3.6
-
-include_package_data = True
-install_requires =
-  pathspec >= 0.5.3
-  pyyaml
-  setuptools
-
-test_suite = tests
-
-[options.packages.find]
-exclude =
-  tests
-  tests.*
-
-[options.package_data]
-yamllint = conf/*.yaml
-
-[options.entry_points]
-console_scripts =
-  yamllint = yamllint.cli:run
-
-[coverage:run]
-relative_files = True

setup.py

@@ -15,15 +15,6 @@
 
 from setuptools import setup
 
-from yamllint import (__author__, __license__,
-                      APP_NAME, APP_VERSION, APP_DESCRIPTION)
-
-
-setup(
-    name=APP_NAME,
-    version=APP_VERSION,
-    author=__author__,
-    description=APP_DESCRIPTION.split('\n')[0],
-    long_description=APP_DESCRIPTION,
-    license=__license__,
-)
+# This is only kept for backward-compatibility with older versions that don't
+# support new packaging standards (e.g. PEP 517 or PEP 660):
+setup()

tests/rules/test_anchors.py

@@ -0,0 +1,209 @@
+# Copyright (C) 2023 Adrien Vergé
+#
+# 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 AnchorsTestCase(RuleTestCase):
+    rule_id = 'anchors'
+
+    def test_disabled(self):
+        conf = 'anchors: disable'
+        self.check('---\n'
+                   '- &b true\n'
+                   '- &i 42\n'
+                   '- &s hello\n'
+                   '- &f_m {k: v}\n'
+                   '- &f_s [1, 2]\n'
+                   '- *b\n'
+                   '- *i\n'
+                   '- *s\n'
+                   '- *f_m\n'
+                   '- *f_s\n'
+                   '---\n'  # redeclare anchors in a new document
+                   '- &b true\n'
+                   '- &i 42\n'
+                   '- &s hello\n'
+                   '- *b\n'
+                   '- *i\n'
+                   '- *s\n'
+                   '---\n'
+                   'block mapping: &b_m\n'
+                   '  key: value\n'
+                   'extended:\n'
+                   '  <<: *b_m\n'
+                   '  foo: bar\n'
+                   '---\n'
+                   '{a: 1, &x b: 2, c: &y 3, *x : 4, e: *y}\n'
+                   '...\n', conf)
+        self.check('---\n'
+                   '- &i 42\n'
+                   '---\n'
+                   '- &b true\n'
+                   '- &b true\n'
+                   '- &b true\n'
+                   '- &s hello\n'
+                   '- *b\n'
+                   '- *i\n'    # declared in a previous document
+                   '- *f_m\n'  # never declared
+                   '- *f_m\n'
+                   '- *f_m\n'
+                   '- *f_s\n'  # declared after
+                   '- &f_s [1, 2]\n'
+                   '---\n'
+                   'block mapping: &b_m\n'
+                   '  key: value\n'
+                   '---\n'
+                   'block mapping 1: &b_m_bis\n'
+                   '  key: value\n'
+                   'block mapping 2: &b_m_bis\n'
+                   '  key: value\n'
+                   'extended:\n'
+                   '  <<: *b_m\n'
+                   '  foo: bar\n'
+                   '---\n'
+                   '{a: 1, &x b: 2, c: &x 3, *x : 4, e: *y}\n'
+                   '...\n', conf)
+
+    def test_forbid_undeclared_aliases(self):
+        conf = ('anchors:\n'
+                '  forbid-undeclared-aliases: true\n'
+                '  forbid-duplicated-anchors: false\n')
+        self.check('---\n'
+                   '- &b true\n'
+                   '- &i 42\n'
+                   '- &s hello\n'
+                   '- &f_m {k: v}\n'
+                   '- &f_s [1, 2]\n'
+                   '- *b\n'
+                   '- *i\n'
+                   '- *s\n'
+                   '- *f_m\n'
+                   '- *f_s\n'
+                   '---\n'  # redeclare anchors in a new document
+                   '- &b true\n'
+                   '- &i 42\n'
+                   '- &s hello\n'
+                   '- *b\n'
+                   '- *i\n'
+                   '- *s\n'
+                   '---\n'
+                   'block mapping: &b_m\n'
+                   '  key: value\n'
+                   'extended:\n'
+                   '  <<: *b_m\n'
+                   '  foo: bar\n'
+                   '---\n'
+                   '{a: 1, &x b: 2, c: &y 3, *x : 4, e: *y}\n'
+                   '...\n', conf)
+        self.check('---\n'
+                   '- &i 42\n'
+                   '---\n'
+                   '- &b true\n'
+                   '- &b true\n'
+                   '- &b true\n'
+                   '- &s hello\n'
+                   '- *b\n'
+                   '- *i\n'    # declared in a previous document
+                   '- *f_m\n'  # never declared
+                   '- *f_m\n'
+                   '- *f_m\n'
+                   '- *f_s\n'  # declared after
+                   '- &f_s [1, 2]\n'
+                   '---\n'
+                   'block mapping: &b_m\n'
+                   '  key: value\n'
+                   '---\n'
+                   'block mapping 1: &b_m_bis\n'
+                   '  key: value\n'
+                   'block mapping 2: &b_m_bis\n'
+                   '  key: value\n'
+                   'extended:\n'
+                   '  <<: *b_m\n'
+                   '  foo: bar\n'
+                   '---\n'
+                   '{a: 1, &x b: 2, c: &x 3, *x : 4, e: *y}\n'
+                   '...\n', conf,
+                   problem1=(9, 3),
+                   problem2=(10, 3),
+                   problem3=(11, 3),
+                   problem4=(12, 3),
+                   problem5=(13, 3),
+                   problem6=(24, 7),
+                   problem7=(27, 37))
+
+    def test_forbid_duplicated_anchors(self):
+        conf = ('anchors:\n'
+                '  forbid-undeclared-aliases: false\n'
+                '  forbid-duplicated-anchors: true\n')
+        self.check('---\n'
+                   '- &b true\n'
+                   '- &i 42\n'
+                   '- &s hello\n'
+                   '- &f_m {k: v}\n'
+                   '- &f_s [1, 2]\n'
+                   '- *b\n'
+                   '- *i\n'
+                   '- *s\n'
+                   '- *f_m\n'
+                   '- *f_s\n'
+                   '---\n'  # redeclare anchors in a new document
+                   '- &b true\n'
+                   '- &i 42\n'
+                   '- &s hello\n'
+                   '- *b\n'
+                   '- *i\n'
+                   '- *s\n'
+                   '---\n'
+                   'block mapping: &b_m\n'
+                   '  key: value\n'
+                   'extended:\n'
+                   '  <<: *b_m\n'
+                   '  foo: bar\n'
+                   '---\n'
+                   '{a: 1, &x b: 2, c: &y 3, *x : 4, e: *y}\n'
+                   '...\n', conf)
+        self.check('---\n'
+                   '- &i 42\n'
+                   '---\n'
+                   '- &b true\n'
+                   '- &b true\n'
+                   '- &b true\n'
+                   '- &s hello\n'
+                   '- *b\n'
+                   '- *i\n'    # declared in a previous document
+                   '- *f_m\n'  # never declared
+                   '- *f_m\n'
+                   '- *f_m\n'
+                   '- *f_s\n'  # declared after
+                   '- &f_s [1, 2]\n'
+                   '---\n'
+                   'block mapping: &b_m\n'
+                   '  key: value\n'
+                   '---\n'
+                   'block mapping 1: &b_m_bis\n'
+                   '  key: value\n'
+                   'block mapping 2: &b_m_bis\n'
+                   '  key: value\n'
+                   'extended:\n'
+                   '  <<: *b_m\n'
+                   '  foo: bar\n'
+                   '---\n'
+                   '{a: 1, &x b: 2, c: &x 3, *x : 4, e: *y}\n'
+                   '...\n', conf,
+                   problem1=(5, 3),
+                   problem2=(6, 3),
+                   problem3=(21, 18),
+                   problem4=(27, 20))

tests/rules/test_colons.py

@@ -256,3 +256,19 @@ class ColonTestCase(RuleTestCase):
                    '  property: {a: 1, b:  2, c : 3}\n', conf,
                    problem1=(3, 11), problem2=(4, 4),
                    problem3=(8, 23), problem4=(8, 28))
+
+    # Although accepted by PyYAML, `{*x: 4}` is not valid YAML: it should be
+    # noted `{*x : 4}`. The reason is that a colon can be part of an anchor
+    # name. See commit message for more details.
+    def test_with_alias_as_key(self):
+        conf = 'colons: {max-spaces-before: 0, max-spaces-after: 1}'
+        self.check('---\n'
+                   '- anchor: &a key\n'
+                   '- *a: 42\n'
+                   '- {*a: 42}\n'
+                   '- *a : 42\n'
+                   '- {*a : 42}\n'
+                   '- *a  : 42\n'
+                   '- {*a  : 42}\n',
+                   conf,
+                   problem1=(7, 6), problem2=(8, 7))

tests/rules/test_float_values.py

@@ -40,6 +40,8 @@ class FloatValuesTestCase(RuleTestCase):
                    '- 0.0\n'
                    '- .1\n'
                    '- \'.1\'\n'
+                   '- string.1\n'
+                   '- .1string\n'
                    '- !custom_tag .2\n'
                    '- &angle1 0.0\n'
                    '- *angle1\n'
@@ -47,7 +49,7 @@ class FloatValuesTestCase(RuleTestCase):
                    '- *angle2\n',
                    conf,
                    problem1=(3, 3),
-                   problem2=(8, 11))
+                   problem2=(10, 11))
 
     def test_scientific_notation(self):
         conf = (
@@ -61,6 +63,8 @@ class FloatValuesTestCase(RuleTestCase):
                    '- 10e-6\n'
                    '- 0.00001\n'
                    '- \'10e-6\'\n'
+                   '- string10e-6\n'
+                   '- 10e-6string\n'
                    '- !custom_tag 10e-6\n'
                    '- &angle1 0.000001\n'
                    '- *angle1\n'
@@ -71,8 +75,8 @@ class FloatValuesTestCase(RuleTestCase):
                    conf,
                    problem1=(2, 3),
                    problem2=(3, 3),
-                   problem3=(9, 11),
-                   problem4=(11, 11))
+                   problem3=(11, 11),
+                   problem4=(13, 11))
 
     def test_nan(self):
         conf = (
@@ -85,13 +89,15 @@ class FloatValuesTestCase(RuleTestCase):
                    '- .NaN\n'
                    '- .NAN\n'
                    '- \'.NaN\'\n'
+                   '- a.NaN\n'
+                   '- .NaNa\n'
                    '- !custom_tag .NaN\n'
                    '- &angle .nan\n'
                    '- *angle\n',
                    conf,
                    problem1=(2, 3),
                    problem2=(3, 3),
-                   problem3=(6, 10))
+                   problem3=(8, 10))
 
     def test_inf(self):
         conf = (
@@ -106,6 +112,8 @@ class FloatValuesTestCase(RuleTestCase):
                    '- -.inf\n'
                    '- -.INF\n'
                    '- \'.inf\'\n'
+                   '- ∞.infinity\n'
+                   '- .infinity∞\n'
                    '- !custom_tag .inf\n'
                    '- &angle .inf\n'
                    '- *angle\n'
@@ -116,5 +124,5 @@ class FloatValuesTestCase(RuleTestCase):
                    problem2=(3, 3),
                    problem3=(4, 3),
                    problem4=(5, 3),
-                   problem5=(8, 10),
-                   problem6=(10, 10))
+                   problem5=(10, 10),
+                   problem6=(12, 10))

tests/rules/test_indentation.py

@@ -1370,6 +1370,45 @@ class IndentationTestCase(RuleTestCase):
                    '               key: value\n'
                    '...\n', conf, problem=(2, 2))
 
+    def test_nested_collections_with_spaces_consistent(self):
+        """Tests behavior of {spaces: consistent} in nested collections to
+        ensure wrong-indentation is properly caught--especially when the
+        expected indent value is initially unknown. For details, see
+        https://github.com/adrienverge/yamllint/issues/485.
+        """
+        conf = ('indentation: {spaces: consistent,\n'
+                '              indent-sequences: true}')
+        self.check('---\n'
+                   '- item:\n'
+                   '  - elem\n'
+                   '- item:\n'
+                   '    - elem\n'
+                   '...\n', conf, problem=(3, 3))
+        conf = ('indentation: {spaces: consistent,\n'
+                '              indent-sequences: false}')
+        self.check('---\n'
+                   '- item:\n'
+                   '  - elem\n'
+                   '- item:\n'
+                   '    - elem\n'
+                   '...\n', conf, problem=(5, 5))
+        conf = ('indentation: {spaces: consistent,\n'
+                '              indent-sequences: consistent}')
+        self.check('---\n'
+                   '- item:\n'
+                   '  - elem\n'
+                   '- item:\n'
+                   '    - elem\n'
+                   '...\n', conf, problem=(5, 5))
+        conf = ('indentation: {spaces: consistent,\n'
+                '              indent-sequences: whatever}')
+        self.check('---\n'
+                   '- item:\n'
+                   '  - elem\n'
+                   '- item:\n'
+                   '    - elem\n'
+                   '...\n', conf)
+
     def test_return(self):
         conf = 'indentation: {spaces: consistent}'
         self.check('---\n'

tests/test_cli.py

@@ -92,12 +92,12 @@ class CommandLineTestCase(unittest.TestCase):
             'no-yaml.json': '---\n'
                             'key: value\n',
             # non-ASCII chars
-            u'non-ascii/éçäγλνπ¥/utf-8': (
-                u'---\n'
-                u'- hétérogénéité\n'
-                u'# 19.99 €\n'
-                u'- お早う御座います。\n'
-                u'# الأَبْجَدِيَّة العَرَبِيَّة\n').encode('utf-8'),
+            'non-ascii/éçäγλνπ¥/utf-8': (
+                '---\n'
+                '- hétérogénéité\n'
+                '# 19.99 €\n'
+                '- お早う御座います。\n'
+                '# الأَبْجَدِيَّة العَرَبِيَّة\n').encode('utf-8'),
             # dos line endings yaml
             'dos.yml': '---\r\n'
                        'dos: true',
@@ -678,6 +678,39 @@ class CommandLineTestCase(unittest.TestCase):
         self.assertEqual(
             (ctx.returncode, ctx.stdout, ctx.stderr), (1, expected_out, ''))
 
+    def test_run_list_files(self):
+        with RunContext(self) as ctx:
+            cli.run(('--list-files', self.wd))
+        self.assertEqual(ctx.returncode, 0)
+        self.assertEqual(
+            sorted(ctx.stdout.splitlines()),
+            [os.path.join(self.wd, 'a.yaml'),
+             os.path.join(self.wd, 'c.yaml'),
+             os.path.join(self.wd, 'dos.yml'),
+             os.path.join(self.wd, 'empty.yml'),
+             os.path.join(self.wd, 'en.yaml'),
+             os.path.join(self.wd, 's/s/s/s/s/s/s/s/s/s/s/s/s/s/s/file.yaml'),
+             os.path.join(self.wd, 'sub/directory.yaml/empty.yml'),
+             os.path.join(self.wd, 'sub/ok.yaml'),
+             os.path.join(self.wd, 'warn.yaml')]
+        )
+
+        config = '{ignore: "*.yml", yaml-files: ["*.*"]}'
+        with RunContext(self) as ctx:
+            cli.run(('--list-files', '-d', config, self.wd))
+        self.assertEqual(ctx.returncode, 0)
+        self.assertEqual(
+            sorted(ctx.stdout.splitlines()),
+            [os.path.join(self.wd, 'a.yaml'),
+             os.path.join(self.wd, 'c.yaml'),
+             os.path.join(self.wd, 'en.yaml'),
+             os.path.join(self.wd, 'no-yaml.json'),
+             os.path.join(self.wd, 's/s/s/s/s/s/s/s/s/s/s/s/s/s/s/file.yaml'),
+             os.path.join(self.wd, 'sub/directory.yaml/not-yaml.txt'),
+             os.path.join(self.wd, 'sub/ok.yaml'),
+             os.path.join(self.wd, 'warn.yaml')]
+        )
+
 
 class CommandLineConfigTestCase(unittest.TestCase):
     def test_config_file(self):

tests/test_config.py

@@ -369,7 +369,7 @@ class ExtendedConfigTestCase(unittest.TestCase):
         self.assertEqual(c.rules['colons']['max-spaces-before'], 0)
         self.assertEqual(c.rules['colons']['max-spaces-after'], 1)
 
-    def test_extended_ignore(self):
+    def test_extended_ignore_str(self):
         with tempfile.NamedTemporaryFile('w') as f:
             f.write('ignore: |\n'
                     '  *.template.yaml\n')
@@ -379,6 +379,16 @@ class ExtendedConfigTestCase(unittest.TestCase):
         self.assertEqual(c.ignore.match_file('test.template.yaml'), True)
         self.assertEqual(c.ignore.match_file('test.yaml'), False)
 
+    def test_extended_ignore_list(self):
+        with tempfile.NamedTemporaryFile('w') as f:
+            f.write('ignore:\n'
+                    '  - "*.template.yaml"\n')
+            f.flush()
+            c = config.YamlLintConfig('extends: ' + f.name + '\n')
+
+        self.assertEqual(c.ignore.match_file('test.template.yaml'), True)
+        self.assertEqual(c.ignore.match_file('test.yaml'), False)
+
 
 class ExtendedLibraryConfigTestCase(unittest.TestCase):
     def test_extend_config_disable_rule(self):
@@ -539,7 +549,7 @@ class IgnoreConfigTestCase(unittest.TestCase):
             './s/s/ign-trail/s/s/file2.lint-me-anyway.yaml:5:5: ' + hyphen,
         )))
 
-    def test_run_with_ignore(self):
+    def test_run_with_ignore_str(self):
         with open(os.path.join(self.wd, '.yamllint'), 'w') as f:
             f.write('extends: default\n'
                     'ignore: |\n'
@@ -593,6 +603,60 @@ class IgnoreConfigTestCase(unittest.TestCase):
             './s/s/ign-trail/s/s/file2.lint-me-anyway.yaml:5:5: ' + hyphen,
         )))
 
+    def test_run_with_ignore_list(self):
+        with open(os.path.join(self.wd, '.yamllint'), 'w') as f:
+            f.write('extends: default\n'
+                    'ignore:\n'
+                    '  - "*.dont-lint-me.yaml"\n'
+                    '  - "/bin/"\n'
+                    '  - "!/bin/*.lint-me-anyway.yaml"\n'
+                    'rules:\n'
+                    '  key-duplicates:\n'
+                    '    ignore:\n'
+                    '      - "/ign-dup"\n'
+                    '  trailing-spaces:\n'
+                    '    ignore:\n'
+                    '      - "ign-trail"\n'
+                    '      - "!*.lint-me-anyway.yaml"\n')
+
+        sys.stdout = StringIO()
+        with self.assertRaises(SystemExit):
+            cli.run(('-f', 'parsable', '.'))
+
+        out = sys.stdout.getvalue()
+        out = '\n'.join(sorted(out.splitlines()))
+
+        docstart = '[warning] missing document start "---" (document-start)'
+        keydup = '[error] duplication of key "key" in mapping (key-duplicates)'
+        trailing = '[error] trailing spaces (trailing-spaces)'
+        hyphen = '[error] too many spaces after hyphen (hyphens)'
+
+        self.assertEqual(out, '\n'.join((
+            './.yamllint:1:1: ' + docstart,
+            './bin/file.lint-me-anyway.yaml:3:3: ' + keydup,
+            './bin/file.lint-me-anyway.yaml:4:17: ' + trailing,
+            './bin/file.lint-me-anyway.yaml:5:5: ' + hyphen,
+            './file-at-root.yaml:3:3: ' + keydup,
+            './file-at-root.yaml:4:17: ' + trailing,
+            './file-at-root.yaml:5:5: ' + hyphen,
+            './ign-dup/file.yaml:4:17: ' + trailing,
+            './ign-dup/file.yaml:5:5: ' + hyphen,
+            './ign-dup/sub/dir/file.yaml:4:17: ' + trailing,
+            './ign-dup/sub/dir/file.yaml:5:5: ' + hyphen,
+            './ign-trail/file.yaml:3:3: ' + keydup,
+            './ign-trail/file.yaml:5:5: ' + hyphen,
+            './include/ign-dup/sub/dir/file.yaml:3:3: ' + keydup,
+            './include/ign-dup/sub/dir/file.yaml:4:17: ' + trailing,
+            './include/ign-dup/sub/dir/file.yaml:5:5: ' + hyphen,
+            './s/s/ign-trail/file.yaml:3:3: ' + keydup,
+            './s/s/ign-trail/file.yaml:5:5: ' + hyphen,
+            './s/s/ign-trail/s/s/file.yaml:3:3: ' + keydup,
+            './s/s/ign-trail/s/s/file.yaml:5:5: ' + hyphen,
+            './s/s/ign-trail/s/s/file2.lint-me-anyway.yaml:3:3: ' + keydup,
+            './s/s/ign-trail/s/s/file2.lint-me-anyway.yaml:4:17: ' + trailing,
+            './s/s/ign-trail/s/s/file2.lint-me-anyway.yaml:5:5: ' + hyphen,
+        )))
+
     def test_run_with_ignore_from_file(self):
         with open(os.path.join(self.wd, '.yamllint'), 'w') as f:
             f.write('extends: default\n'

tests/test_linter.py

@@ -31,10 +31,10 @@ class LinterTestCase(unittest.TestCase):
         linter.run(b'test: document', self.fake_config())
 
     def test_run_on_unicode(self):
-        linter.run(u'test: document', self.fake_config())
+        linter.run('test: document', self.fake_config())
 
     def test_run_on_stream(self):
-        linter.run(io.StringIO(u'hello'), self.fake_config())
+        linter.run(io.StringIO('hello'), self.fake_config())
 
     def test_run_on_int(self):
         self.assertRaises(TypeError, linter.run, 42, self.fake_config())
@@ -44,14 +44,14 @@ class LinterTestCase(unittest.TestCase):
                           ['h', 'e', 'l', 'l', 'o'], self.fake_config())
 
     def test_run_on_non_ascii_chars(self):
-        s = (u'- hétérogénéité\n'
-             u'# 19.99 €\n')
+        s = ('- hétérogénéité\n'
+             '# 19.99 €\n')
         linter.run(s, self.fake_config())
         linter.run(s.encode('utf-8'), self.fake_config())
         linter.run(s.encode('iso-8859-15'), self.fake_config())
 
-        s = (u'- お早う御座います。\n'
-             u'# الأَبْجَدِيَّة العَرَبِيَّة\n')
+        s = ('- お早う御座います。\n'
+             '# الأَبْجَدِيَّة العَرَبِيَّة\n')
         linter.run(s, self.fake_config())
         linter.run(s.encode('utf-8'), self.fake_config())
 

tests/test_spec_examples.py

@@ -13,7 +13,6 @@
 # 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 io import open
 import os
 
 from tests.common import RuleTestCase

yamllint/__init__.py

@@ -21,10 +21,10 @@ indentation, etc."""
 
 
 APP_NAME = 'yamllint'
-APP_VERSION = '1.28.0'
+APP_VERSION = '1.31.0'
 APP_DESCRIPTION = __doc__
 
-__author__ = u'Adrien Vergé'
-__copyright__ = u'Copyright 2022, Adrien Vergé'
+__author__ = 'Adrien Vergé'
+__copyright__ = 'Copyright 2022, Adrien Vergé'
 __license__ = 'GPLv3'
 __version__ = APP_VERSION

yamllint/cli.py

@@ -14,7 +14,6 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import argparse
-import io
 import locale
 import os
 import platform
@@ -47,7 +46,7 @@ def supports_color():
             hasattr(sys.stdout, 'isatty') and sys.stdout.isatty())
 
 
-class Format(object):
+class Format:
     @staticmethod
     def parsable(problem, filename):
         return ('%(file)s:%(line)s:%(column)s: [%(level)s] %(message)s' %
@@ -158,6 +157,8 @@ def run(argv=None):
     config_group.add_argument('-d', '--config-data', dest='config_data',
                               action='store',
                               help='custom configuration (as YAML source)')
+    parser.add_argument('--list-files', action='store_true', dest='list_files',
+                        help='list files to lint and exit')
     parser.add_argument('-f', '--format',
                         choices=('parsable', 'standard', 'colored', 'github',
                                  'auto'),
@@ -208,14 +209,20 @@ def run(argv=None):
     if conf.locale is not None:
         locale.setlocale(locale.LC_ALL, conf.locale)
 
+    if args.list_files:
+        for file in find_files_recursively(args.files, conf):
+            if not conf.is_file_ignored(file):
+                print(file)
+        sys.exit(0)
+
     max_level = 0
 
     for file in find_files_recursively(args.files, conf):
         filepath = file[2:] if file.startswith('./') else file
         try:
-            with io.open(file, newline='') as f:
+            with open(file, newline='') as f:
                 problems = linter.run(f, conf, filepath)
-        except EnvironmentError as e:
+        except OSError as e:
             print(e, file=sys.stderr)
             sys.exit(-1)
         prob_level = show_problems(problems, file, args_format=args.format,
@@ -226,7 +233,7 @@ def run(argv=None):
     if args.stdin:
         try:
             problems = linter.run(sys.stdin, conf, '')
-        except EnvironmentError as e:
+        except OSError as e:
             print(e, file=sys.stderr)
             sys.exit(-1)
         prob_level = show_problems(problems, 'stdin', args_format=args.format,

yamllint/conf/default.yaml

@@ -6,6 +6,7 @@ yaml-files:
   - '.yamllint'
 
 rules:
+  anchors: enable
   braces: enable
   brackets: enable
   colons: enable

yamllint/config.py

@@ -112,11 +112,16 @@ class YamlLintConfig:
             with fileinput.input(conf['ignore-from-file']) as f:
                 self.ignore = pathspec.PathSpec.from_lines('gitwildmatch', f)
         elif 'ignore' in conf:
-            if not isinstance(conf['ignore'], str):
+            if isinstance(conf['ignore'], str):
+                self.ignore = pathspec.PathSpec.from_lines(
+                    'gitwildmatch', conf['ignore'].splitlines())
+            elif (isinstance(conf['ignore'], list) and
+                    all(isinstance(line, str) for line in conf['ignore'])):
+                self.ignore = pathspec.PathSpec.from_lines(
+                    'gitwildmatch', conf['ignore'])
+            else:
                 raise YamlLintConfigError(
                     'invalid config: ignore should contain file patterns')
-            self.ignore = pathspec.PathSpec.from_lines(
-                'gitwildmatch', conf['ignore'].splitlines())
 
         if 'yaml-files' in conf:
             if not (isinstance(conf['yaml-files'], list)
@@ -150,11 +155,16 @@ def validate_rule_conf(rule, conf):
     if isinstance(conf, dict):
         if ('ignore' in conf and
                 not isinstance(conf['ignore'], pathspec.pathspec.PathSpec)):
-            if not isinstance(conf['ignore'], str):
+            if isinstance(conf['ignore'], str):
+                conf['ignore'] = pathspec.PathSpec.from_lines(
+                    'gitwildmatch', conf['ignore'].splitlines())
+            elif (isinstance(conf['ignore'], list) and
+                    all(isinstance(line, str) for line in conf['ignore'])):
+                conf['ignore'] = pathspec.PathSpec.from_lines(
+                    'gitwildmatch', conf['ignore'])
+            else:
                 raise YamlLintConfigError(
                     'invalid config: ignore should contain file patterns')
-            conf['ignore'] = pathspec.PathSpec.from_lines(
-                'gitwildmatch', conf['ignore'].splitlines())
 
         if 'level' not in conf:
             conf['level'] = 'error'

yamllint/linter.py

@@ -14,6 +14,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import re
+import io
 
 import yaml
 
@@ -33,7 +34,7 @@ DISABLE_RULE_PATTERN = re.compile(r'^# yamllint disable( rule:\S+)*\s*$')
 ENABLE_RULE_PATTERN = re.compile(r'^# yamllint enable( rule:\S+)*\s*$')
 
 
-class LintProblem(object):
+class LintProblem:
     """Represents a linting problem found by yamllint."""
     def __init__(self, line, column, desc='<no description>', rule=None):
         #: Line on which the problem was found (starting at 1)
@@ -121,7 +122,7 @@ def get_cosmetic_problems(buffer, conf, filepath):
                         if id in self.all_rules:
                             self.rules.add(id)
 
-    # Use a cache to store problems and flush it only when a end of line is
+    # Use a cache to store problems and flush it only when an end of line is
     # found. This allows the use of yamllint directive to disable some rules on
     # some lines.
     cache = []
@@ -222,12 +223,12 @@ def run(input, conf, filepath=None):
     :param input: buffer, string or stream to read from
     :param conf: yamllint configuration object
     """
-    if conf.is_file_ignored(filepath):
+    if filepath is not None and conf.is_file_ignored(filepath):
         return ()
 
     if isinstance(input, (bytes, str)):
         return _run(input, conf, filepath)
-    elif hasattr(input, 'read'):  # Python 2's file or Python 3's io.IOBase
+    elif isinstance(input, io.IOBase):
         # We need to have everything in memory to parse correctly
         content = input.read()
         return _run(content, conf, filepath)

yamllint/parser.py

@@ -132,8 +132,7 @@ def token_or_comment_generator(buffer):
 
             yield Token(curr.start_mark.line + 1, curr, prev, next, nextnext)
 
-            for comment in comments_between_tokens(curr, next):
-                yield comment
+            yield from comments_between_tokens(curr, next)
 
             prev = curr
             curr = next

yamllint/rules/__init__.py

@@ -14,6 +14,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 from yamllint.rules import (
+    anchors,
     braces,
     brackets,
     colons,
@@ -39,6 +40,7 @@ from yamllint.rules import (
 )
 
 _RULES = {
+    anchors.ID: anchors,
     braces.ID: braces,
     brackets.ID: brackets,
     colons.ID: colons,

yamllint/rules/anchors.py

@@ -0,0 +1,118 @@
+# Copyright (C) 2023 Adrien Vergé
+#
+# 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 report duplicated anchors and aliases referencing undeclared
+anchors.
+
+.. rubric:: Options
+
+* Set ``forbid-undeclared-aliases`` to ``true`` to avoid aliases that reference
+  an anchor that hasn't been declared (either not declared at all, or declared
+  later in the document).
+* Set ``forbid-duplicated-anchors`` to ``true`` to avoid duplications of a same
+  anchor.
+
+.. rubric:: Default values (when enabled)
+
+.. code-block:: yaml
+
+ rules:
+   anchors:
+     forbid-undeclared-aliases: true
+     forbid-duplicated-anchors: false
+
+.. rubric:: Examples
+
+#. With ``anchors: {forbid-undeclared-aliases: true}``
+
+   the following code snippet would **PASS**:
+   ::
+
+    ---
+    - &anchor
+      foo: bar
+    - *anchor
+
+   the following code snippet would **FAIL**:
+   ::
+
+    ---
+    - &anchor
+      foo: bar
+    - *unknown
+
+   the following code snippet would **FAIL**:
+   ::
+
+    ---
+    - &anchor
+      foo: bar
+    - <<: *unknown
+      extra: value
+
+#. With ``anchors: {forbid-duplicated-anchors: true}``
+
+   the following code snippet would **PASS**:
+   ::
+
+    ---
+    - &anchor1 Foo Bar
+    - &anchor2 [item 1, item 2]
+
+   the following code snippet would **FAIL**:
+   ::
+
+    ---
+    - &anchor Foo Bar
+    - &anchor [item 1, item 2]
+"""
+
+
+import yaml
+
+from yamllint.linter import LintProblem
+
+
+ID = 'anchors'
+TYPE = 'token'
+CONF = {'forbid-undeclared-aliases': bool,
+        'forbid-duplicated-anchors': bool}
+DEFAULT = {'forbid-undeclared-aliases': True,
+           'forbid-duplicated-anchors': False}
+
+
+def check(conf, token, prev, next, nextnext, context):
+    if conf['forbid-undeclared-aliases'] or conf['forbid-duplicated-anchors']:
+        if isinstance(token, (yaml.StreamStartToken, yaml.DocumentStartToken)):
+            context['anchors'] = set()
+
+    if (conf['forbid-undeclared-aliases'] and
+            isinstance(token, yaml.AliasToken) and
+            token.value not in context['anchors']):
+        yield LintProblem(
+            token.start_mark.line + 1, token.start_mark.column + 1,
+            f'found undeclared alias "{token.value}"')
+
+    if (conf['forbid-duplicated-anchors'] and
+            isinstance(token, yaml.AnchorToken) and
+            token.value in context['anchors']):
+        yield LintProblem(
+            token.start_mark.line + 1, token.start_mark.column + 1,
+            f'found duplicated anchor "{token.value}"')
+
+    if conf['forbid-undeclared-aliases'] or conf['forbid-duplicated-anchors']:
+        if isinstance(token, yaml.AnchorToken):
+            context['anchors'].add(token.value)

yamllint/rules/colons.py

@@ -92,7 +92,9 @@ DEFAULT = {'max-spaces-before': 0,
 
 
 def check(conf, token, prev, next, nextnext, context):
-    if isinstance(token, yaml.ValueToken):
+    if isinstance(token, yaml.ValueToken) and not (
+            isinstance(prev, yaml.AliasToken) and
+            token.start_mark.pointer - prev.end_mark.pointer == 1):
         problem = spaces_before(token, prev, next,
                                 max=conf['max-spaces-before'],
                                 max_desc='too many spaces before colon')

yamllint/rules/comments_indentation.py

@@ -117,8 +117,7 @@ def check(conf, comment):
     #         # comment
     #         - 1
     #         - 2
-    if prev_line_indent <= next_line_indent:
-        prev_line_indent = next_line_indent
+    prev_line_indent = max(prev_line_indent, next_line_indent)
 
     # If two indents are valid but a previous comment went back to normal
     # indent, for the next ones to do the same. In other words, avoid this:

yamllint/rules/float_values.py

@@ -107,13 +107,13 @@ DEFAULT = {
 }
 
 IS_NUMERAL_BEFORE_DECIMAL_PATTERN = (
-    re.compile('[-+]?(\\.[0-9]+)([eE][-+]?[0-9]+)?')
+    re.compile('[-+]?(\\.[0-9]+)([eE][-+]?[0-9]+)?$')
 )
 IS_SCIENTIFIC_NOTATION_PATTERN = re.compile(
-    '[-+]?(\\.[0-9]+|[0-9]+(\\.[0-9]*)?)([eE][-+]?[0-9]+)'
+    '[-+]?(\\.[0-9]+|[0-9]+(\\.[0-9]*)?)([eE][-+]?[0-9]+)$'
 )
-IS_INF_PATTERN = re.compile('[-+]?(\\.inf|\\.Inf|\\.INF)')
-IS_NAN_PATTERN = re.compile('\\.nan|\\.NaN|\\.NAN')
+IS_INF_PATTERN = re.compile('[-+]?(\\.inf|\\.Inf|\\.INF)$')
+IS_NAN_PATTERN = re.compile('(\\.nan|\\.NaN|\\.NAN)$')
 
 
 def check(conf, token, prev, next, nextnext, context):

yamllint/rules/indentation.py

@@ -341,14 +341,18 @@ def _check(conf, token, prev, next, nextnext, context):
             expected = detect_indent(expected, token)
 
         if found_indentation != expected:
-            yield LintProblem(token.start_mark.line + 1, found_indentation + 1,
-                              'wrong indentation: expected %d but found %d' %
-                              (expected, found_indentation))
+            if expected < 0:
+                message = 'wrong indentation: expected at least %d' % \
+                          (found_indentation + 1)
+            else:
+                message = 'wrong indentation: expected %d but found %d' % \
+                          (expected, found_indentation)
+            yield LintProblem(token.start_mark.line + 1,
+                              found_indentation + 1, message)
 
     if (isinstance(token, yaml.ScalarToken) and
             conf['check-multi-line-strings']):
-        for problem in check_scalar_indentation(conf, token, context):
-            yield problem
+        yield from check_scalar_indentation(conf, token, context)
 
     # Step 2.a:
 
@@ -493,8 +497,8 @@ def _check(conf, token, prev, next, nextnext, context):
                         # indentation it should have (because `spaces` is
                         # `consistent` and its value has not been computed yet
                         # -- this is probably the beginning of the document).
-                        # So we choose an arbitrary value (2).
-                        indent = 2
+                        # So we choose an unknown value (-1).
+                        indent = -1
                     else:
                         indent = detect_indent(context['stack'][-1].indent,
                                                next)
@@ -576,8 +580,7 @@ def _check(conf, token, prev, next, nextnext, context):
 
 def check(conf, token, prev, next, nextnext, context):
     try:
-        for problem in _check(conf, token, prev, next, nextnext, context):
-            yield problem
+        yield from _check(conf, token, prev, next, nextnext, context)
     except AssertionError:
         yield LintProblem(token.start_mark.line + 1,
                           token.start_mark.column + 1,

yamllint/rules/key_ordering.py

@@ -93,7 +93,7 @@ TYPE = 'token'
 MAP, SEQ = range(2)
 
 
-class Parent(object):
+class Parent:
     def __init__(self, type):
         self.type = type
         self.keys = []

yamllint/rules/new_line_at_end_of_file.py

@@ -17,7 +17,7 @@
 Use this rule to require a new line character (``\\n``) at the end of files.
 
 The POSIX standard `requires the last line to end with a new line character
-<http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap03.html#tag_03_206>`_.
+<https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap03.html#tag_03_206>`_.
 All UNIX tools expect a new line at the end of files. Most text editors use
 this convention too.
 """

yamllint/rules/quoted_strings.py

@@ -166,7 +166,7 @@ def VALIDATE(conf):
         return 'cannot use both "required: false" and "extra-allowed"'
 
 
-DEFAULT_SCALAR_TAG = u'tag:yaml.org,2002:str'
+DEFAULT_SCALAR_TAG = 'tag:yaml.org,2002:str'
 
 # https://stackoverflow.com/a/36514274
 yaml.resolver.Resolver.add_implicit_resolver(
@@ -228,7 +228,7 @@ def check(conf, token, prev, next, nextnext, context):
         return
 
     # Ignore multi-line strings
-    if (not token.plain) and (token.style == "|" or token.style == ">"):
+    if not token.plain and token.style in ("|", ">"):
         return
 
     quote_type = conf['quote-type']

yamllint/rules/truthy.py

@@ -14,7 +14,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 """
-Use this rule to forbid non-explictly typed truthy values other than allowed
+Use this rule to forbid non-explicitly typed truthy values other than allowed
 ones (by default: ``true`` and ``false``), for example ``YES`` or ``off``.
 
 This can be useful to prevent surprises from YAML parsers transforming