A linter for YAML files.
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Adrien Vergé ebd6b90d3e anchors: Add new rule to detect undeclared or duplicated anchors
According to the YAML specification [^1]:

- > It is an error for an alias node to use an anchor that does not
  > previously occur in the document.

  The `forbid-undeclared-aliases` option checks that aliases do have a
  matching anchor declared previously in the document. Since this is
  required by the YAML spec, this option is enabled by default.

- > The alias refers to the most recent preceding node having the same
  > anchor.

  This means that having a same anchor repeated in a document is
  allowed. However users could want to avoid this, so the new option
  `forbid-duplicated-anchors` allows that. It's disabled by default.

- > It is not an error to specify an anchor that is not used by any
  > alias node.

  This means that it's OK to declare anchors but don't have any alias
  referencing them. However users could want to avoid this, so a new
  option (e.g. `forbid-unused-anchors`) could be implemented in the
  future. See https://github.com/adrienverge/yamllint/pull/537.

Fixes #395
Closes #420

[^1]: https://yaml.org/spec/1.2.2/#71-alias-nodes
2023-03-22 10:34:35 +01:00
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docs anchors: Add new rule to detect undeclared or duplicated anchors 2023-03-22 10:34:35 +01:00
tests anchors: Add new rule to detect undeclared or duplicated anchors 2023-03-22 10:34:35 +01:00
yamllint anchors: Add new rule to detect undeclared or duplicated anchors 2023-03-22 10:34:35 +01:00
.gitignore gitignore: Add /.eggs 2020-09-27 10:06:33 +02:00
.pre-commit-hooks.yaml pre-commit is now served over https! 2018-03-03 08:01:24 +01:00
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CONTRIBUTING.rst docs: Update CONTRIBUTING.rst 2021-10-20 09:40:59 +02:00
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yamllint
========

A linter for YAML files.

yamllint does not only check for syntax validity, but for weirdnesses like key
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
   :alt: CI tests status
.. image::
   https://coveralls.io/repos/github/adrienverge/yamllint/badge.svg?branch=master
   :target: https://coveralls.io/github/adrienverge/yamllint?branch=master
   :alt: Code coverage status
.. image:: https://readthedocs.org/projects/yamllint/badge/?version=latest
   :target: https://yamllint.readthedocs.io/en/latest/?badge=latest
   :alt: Documentation status

Written in Python (compatible with Python 3 only).

Documentation
-------------

https://yamllint.readthedocs.io/

Overview
--------

Screenshot
^^^^^^^^^^

.. image:: docs/screenshot.png
   :alt: yamllint screenshot

Installation
^^^^^^^^^^^^

Using pip, the Python package manager:

.. code:: bash

 pip install --user yamllint

yamllint is also packaged for all major operating systems, see installation
examples (``dnf``, ``apt-get``...) `in the documentation
<https://yamllint.readthedocs.io/en/stable/quickstart.html>`_.

Usage
^^^^^

.. code:: bash

 # Lint one or more files
 yamllint my_file.yml my_other_file.yaml ...

.. code:: bash

 # Lint all YAML files in a directory
 yamllint .

.. code:: bash

 # Use a pre-defined lint configuration
 yamllint -d relaxed file.yaml

 # Use a custom lint configuration
 yamllint -c /path/to/myconfig file-to-lint.yaml

.. code:: bash

 # Output a parsable format (for syntax checking in editors like Vim, emacs...)
 yamllint -f parsable file.yaml

`Read more in the complete documentation! <https://yamllint.readthedocs.io/>`__

Features
^^^^^^^^

Here is a yamllint configuration file example:

.. code:: yaml

 extends: default

 rules:
   # 80 chars should be enough, but don't fail if a line is longer
   line-length:
     max: 80
     level: warning

   # don't bother me with this rule
   indentation: disable

Within a YAML file, special comments can be used to disable checks for a single
line:

.. code:: yaml

 This line is waaaaaaaaaay too long  # yamllint disable-line

or for a whole block:

.. code:: yaml

 # yamllint disable rule:colons
 - Lorem       : ipsum
   dolor       : sit amet,
   consectetur : adipiscing elit
 # yamllint enable

Specific files can be ignored (totally or for some rules only) using a
``.gitignore``-style pattern:

.. code:: yaml

 # For all rules
 ignore: |
   *.dont-lint-me.yaml
   /bin/
   !/bin/*.lint-me-anyway.yaml

 rules:
   key-duplicates:
     ignore: |
       generated
       *.template.yaml
   trailing-spaces:
     ignore: |
       *.ignore-trailing-spaces.yaml
       /ascii-art/*

`Read more in the complete documentation! <https://yamllint.readthedocs.io/>`__

License
-------

`GPL version 3 <LICENSE>`_