flask/CONTRIBUTING.rst

How to contribute to Flask
==========================

Thank you for considering contributing to Flask!


Support questions
-----------------

Please, don't use the issue tracker for this. Use one of the following
resources for questions about your own code:

-   The ``#get-help`` channel on our Discord chat:
    https://discord.gg/t6rrQZH

    -   The IRC channel ``#pocoo`` on FreeNode is linked to Discord, but
        Discord is preferred.

-   The mailing list flask@python.org for long term discussion or larger
    issues.
-   Ask on `Stack Overflow`_. Search with Google first using:
    ``site:stackoverflow.com flask {search term, exception message, etc.}``

.. _Stack Overflow: https://stackoverflow.com/questions/tagged/flask?sort=linked


Reporting issues
----------------

-   Describe what you expected to happen.
-   If possible, include a `minimal reproducible example`_ to help us
    identify the issue. This also helps check that the issue is not with
    your own code.
-   Describe what actually happened. Include the full traceback if there
    was an exception.
-   List your Python, Flask, and Werkzeug versions. If possible, check
    if this issue is already fixed in the repository.

.. _minimal reproducible example: https://stackoverflow.com/help/minimal-reproducible-example


Submitting patches
------------------

-   Use `Black`_ to autoformat your code. This should be done for you as
    a Git `pre-commit`_ hook, set up below. You may also wish to use
    Black's `Editor integration`_.
-   Include tests if your patch is supposed to solve a bug, and explain
    clearly under which circumstances the bug happens. Make sure the
    test fails without your patch.
-   Include a string like "Fixes #123" in your commit message (where 123
    is the issue you fixed). See `Closing issues using keywords
    <https://help.github.com/articles/creating-a-pull-request/>`__.


First time setup
~~~~~~~~~~~~~~~~

-   Download and install the `latest version of git`_.
-   Configure git with your `username`_ and `email`_.

    .. code-block:: text

        $ git config --global user.name 'your name'
        $ git config --global user.email 'your email'

-   Make sure you have a `GitHub account`_.
-   Fork Flask to your GitHub account by clicking the `Fork`_ button.
-   `Clone`_ your GitHub fork locally.

    .. code-block:: text

        $ git clone https://github.com/{username}/flask
        $ cd flask

-   Add the main repository as a remote to update later.

    .. code-block:: text

        $ git remote add pallets https://github.com/pallets/flask
        $ git fetch pallets

-   Create a virtualenv.

    .. code-block:: text

        $ python3 -m venv env
        $ . env/bin/activate

    On Windows, activating is different.

    .. code-block:: text

        > env\Scripts\activate

-   Install Flask in editable mode with development dependencies.

    .. code-block:: text

        $ pip install -e . -r requirements/dev.txt

-   Install the pre-commit hooks.

    .. code-block:: text

        $ pre-commit install

.. _GitHub account: https://github.com/join
.. _latest version of git: https://git-scm.com/downloads
.. _username: https://help.github.com/en/articles/setting-your-username-in-git
.. _email: https://help.github.com/en/articles/setting-your-commit-email-address-in-git
.. _Fork: https://github.com/pallets/flask/fork
.. _Clone: https://help.github.com/en/articles/fork-a-repo#step-2-create-a-local-clone-of-your-fork
.. _pre-commit framework: https://pre-commit.com/#install


Start coding
~~~~~~~~~~~~

-   Create a branch to identify the issue you would like to work on. If
    you're submitting a bug or documentation fix, branch off of the
    latest ".x" branch.

    .. code-block:: text

        $ git checkout -b your-branch-name origin/1.0.x

    If you're submitting a feature addition or change, branch off of the
    "master" branch.

    .. code-block:: text

        $ git checkout -b your-branch-name origin/master

-   Using your favorite editor, make your changes,
    `committing as you go`_.
-   Include tests that cover any code changes you make. Make sure the
    test fails without your patch.
    `Run the tests <contributing-testsuite_>`_.
-   Push your commits to GitHub and `create a pull request`_.

    .. code-block:: text

        $ git push --set-upstream origin your-branch-name

.. _committing as you go: https://dont-be-afraid-to-commit.readthedocs.io/en/latest/git/commandlinegit.html#commit-your-changes
.. _Black: https://black.readthedocs.io
.. _Editor integration: https://black.readthedocs.io/en/stable/editor_integration.html
.. _pre-commit: https://pre-commit.com
.. _create a pull request: https://help.github.com/en/articles/creating-a-pull-request


.. _contributing-testsuite: #running-the-tests

Running the tests
~~~~~~~~~~~~~~~~~

Run the basic test suite with pytest.

.. code-block:: text

    $ pytest

This only runs the tests for the current environment. Whether this is
relevant depends on which part of Flask you're working on. CI will run
the full suite when you submit your pull request.

The full test suite takes a long time to run because it tests multiple
combinations of Python and dependencies. If you don't have a Python
version installed, it will be skipped with a warning message at the end.

.. code-block:: text

    $ tox


Running test coverage
~~~~~~~~~~~~~~~~~~~~~

Generating a report of lines that do not have test coverage can indicate
where to start contributing. Run ``pytest`` using ``coverage`` and
generate a report on the terminal and as an interactive HTML document.

.. code-block:: text

    $ coverage run -m pytest
    $ coverage report
    $ coverage html  # then open htmlcov/index.html

Read more about `coverage <https://coverage.readthedocs.io>`_.

Running the full test suite with ``tox`` will combine the coverage reports
from all runs.


Building the docs
~~~~~~~~~~~~~~~~~

Build the docs in the ``docs`` directory using Sphinx.

.. code-block:: text

    $ cd docs
    $ make html

Open ``_build/html/index.html`` in your browser to view the docs.

Read more about `Sphinx <https://www.sphinx-doc.org/en/master/>`_.


Caution: zero-padded file modes
-------------------------------

This repository contains several zero-padded file modes that may cause
issues when pushing this repository to Git hosts other than GitHub.
Fixing this is destructive to the commit history, so we suggest ignoring
these warnings. If it fails to push and you're using a self-hosted Git
service like GitLab, you can turn off repository checks in the admin
panel.

These files can also cause issues while cloning if you have
``fsckObjects`` enabled with either of the following in your git config.

.. code-block::

    [fetch]
    fsckObjects = true

    [receive]
    fsckObjects = true

The only solution is to set both of the above to ``false``, clone, and
then set them back to ``true`` after.