gitchangelog 2.4.0

gitchangelog generates a changelog thanks to git log.

============
gitchangelog
============

.. image:: http://img.shields.io/pypi/v/gitchangelog.svg?style=flat
:target: https://pypi.python.org/pypi/gitchangelog/
:alt: Latest PyPI version

.. image:: http://img.shields.io/pypi/dm/gitchangelog.svg?style=flat
:target: https://pypi.python.org/pypi/gitchangelog/
:alt: Number of PyPI downloads

.. image:: http://img.shields.io/travis/vaab/gitchangelog/master.svg?style=flat
:target: https://travis-ci.org/vaab/gitchangelog/
:alt: Travis CI build status

.. image:: http://img.shields.io/coveralls/vaab/gitchangelog/master.svg?style=flat
:target: https://coveralls.io/r/vaab/gitchangelog
:alt: Test coverage


Use your commit log to make beautifull and configurable changelog file.


Feature
=======

- fully driven by a config file that can be tailored with your changelog
policies. (see for example the `sample configuration file`_)
- filter out commits/tags based on regexp matching
- refactor commit summary, or commit body on the fly with replace regexp
- classify commit message into sections (ie: New, Fix, Changes...)
- any output format supported thanks to templating, you can even choose
your own preferred template engine (mako, mustache, full python ...).
- support your merge or rebase workflows and complicated git histories
- support full or incremental changelog generation to match your needs.


Requirements
============

``gitchangelog`` is compatible Python 2 and Python 3.

It should work on Linux/BSD/MacOSX and any help with Windows
compatibility would be appreciated.

Please submit an issue if you encounter incompatibilies.


Sample
======

The default output is ReSTructured text, so it should be readable in ASCII.

Here is a small sample of the ``gitchangelog`` changelog at work.

Current ``git log`` output so you can get an idea of the log history::

* 59f902a Valentin Lab new: dev: sections in changelog are now in the order given in ``gitchangelog.rc`` in the ``section_regexps`` option. (0.1.2)
* c6f72cc Valentin Lab chg: dev: commented code to toggle doctest mode.
* a9c38f3 Valentin Lab fix: dev: doctests were failing on this.
* 59524e6 Valentin Lab new: usr: added ``body_split_regexp`` option to attempts to format correctly body of commit.
* 5883f07 Valentin Lab new: usr: use a list of tuple instead of a dict for ``section_regexps`` to be able to manage order between section on find match.
* 7c1d480 Valentin Lab new: dev: new ``unreleased_version_label`` option in ``gitchangelog.rc`` to change label of not yet released code.
* cf29c9c Valentin Lab fix: dev: bad sorting of tags (alphanumerical). Changed to commit date sort.
* 61d8f80 Valentin Lab fix: dev: support of empty commit message.
* eeca31b Valentin Lab new: dev: use ``gitchangelog`` section in ``git config`` world appropriately.
* 6142b71 Valentin Lab chg: dev: cosmetic removal of trailing whitespaces
* 3c3edd5 Valentin Lab fix: usr: ``git`` in later versions seems to fail on ``git config <key>`` with errlvl 255, that was not supported.
* 3f9617d Valentin Lab fix: usr: removed Traceback when there were no tags at all in the current git repository.
* e0db9ae Valentin Lab new: usr: added section classifiers (ie: New, Change, Bugs) and updated the sample rc file. (0.1.1)
* 0c66d59 Valentin Lab fix: dev: Fixed case where exception was thrown if two tags are on the same commit.
* d2fae0d Valentin Lab new: usr: added a succint ``--help`` support.

And here is the ``gitchangelog`` output::

0.1.2 (2011-05-17)
------------------

New
~~~

- Sections in changelog are now in the order given in ``git-
changelog.rc`` in the ``section_regexps`` option. [Valentin Lab]

- Added ``body_split_regexp`` option to attempts to format correctly
body of commit. [Valentin Lab]

- Use a list of tuple instead of a dict for ``section_regexps`` to be
able to manage order between section on find match. [Valentin Lab]

- New ``unreleased_version_label`` option in ``gitchangelog.rc`` to
change label of not yet released code. [Valentin Lab]

- Use ``gitchangelog`` section in ``git config`` world appropriately.
[Valentin Lab]

Changes
~~~~~~~

- Commented code to toggle doctest mode. [Valentin Lab]

- Cosmetic removal of trailing whitespaces. [Valentin Lab]

Fix
~~~

- Doctests were failing on this. [Valentin Lab]

- Bad sorting of tags (alphanumerical). Changed to commit date sort.
[Valentin Lab]

- Support of empty commit message. [Valentin Lab]

- ``git`` in later versions seems to fail on ``git config <key>`` with
errlvl 255, that was not supported. [Valentin Lab]

- Removed Traceback when there were no tags at all in the current git
repository. [Valentin Lab]

0.1.1 (2011-04-07)
------------------

New
~~~

- Added section classifiers (ie: New, Change, Bugs) and updated the
sample rc file. [Valentin Lab]

- Added a succint ``--help`` support. [Valentin Lab]

Fix
~~~

- Fixed case where exception was thrown if two tags are on the same
commit. [Valentin Lab]

And the rendered full result is directly used to generate the HTML webpage of
the `changelog of the PyPI page`_.


Usage
=====

You need to place a ``gitchangelog.rc`` file somewhere, the
recommended location is the root of the current git repository with
the name ``.gitchangelog.rc``. However you could put it elsewhere,
and here are the locations checked (first match will prevail):

- in the path given thanks to the environment variable
``GITCHANGELOG_CONFIG_FILENAME``
- in the path stored in git config's entry ``gitchangelog.rc-path`` (which
could be stored in system location or per repository)
- (RECOMMENDED) in the root of the current git repository with the name
``.gitchangelog.rc``

Then, you'll be able to call ``gitchangelog`` in a GIT repository and it'll
print changelog on its standard output.


Configuration file format
-------------------------

The `sample configuration file`_ is quite heavily commented and is quite
simple. You should be able to use it as required.

.. _sample configuration file: http://github.com/vaab/gitchangelog/blob/master/gitchangelog.rc.reference

The changelog of gitchangelog is generated with himself and with the sample
configuration file. You'll see the output in the `changelog of the PyPI page`_.

.. _changelog of the PyPI page: http://pypi.python.org/pypi/gitchangelog


Output Engines
--------------

At the end of the configuration file, you'll notice a variable called
``output_engine``. By default, it's set to ``rest_py``, which is the
legacy python engine to produce the `ReSTructured Text` output format
that is shown in above samples. If this engine fits your needs, you
won't need to fiddle with this option.

To render the template, ``gitchangelog`` will generate a data structure that
will then be rendered thanks to the output engine. This should help you get
the exact output that you need.

As people might have different needs and knowledge, a templating
system using ``mustache`` is available. ``mustache`` templates are
provided to render both `ReSTructured Text` or `markdown` formats. If
you know ``mustache`` templating, then you could easily add or modify
these existing templates.

A ``mako`` templating engine is also provided. You'll find also a ``mako``
template producing the same `ReSTructured Text` output than the legacy one.
It's provided for reference and/or further tweak if you would rather use `mako`_
templates.


Mustache
~~~~~~~~

The ``mustache`` output engine uses `mustache templates`_.

The `mustache`_ templates for ``gitchangelog`` are located in
``templates/mustache`` and are powered via `pystache`_ the python
implementation of the `mustache`_ specifications. So `mustache`_ output engine
will only be available if you have `pystache`_ module available in your python
environment.

.. _mustache: http://mustache.github.io
.. _pystache: https://pypi.python.org/pypi/pystache
.. _mustache templates: http://mustache.github.io/mustache.5.html


Mako
~~~~

The ``makotemplate`` output engine templates for ``gitchangelog`` are located in
``templates/mako`` and are powered via `mako`_ python templating system. So
`mako`_ output engine will only be available if you have `mako`_ module
available in your python environment.

.. _mako: http://www.makotemplates.org


Changelog data tree
~~~~~~~~~~~~~~~~~~~

This is a sample of the current data structure sent to output engines::

{'title': 'Changelog',
'versions': [{'label': '%%version%% (unreleased)',
'date': None,
'tag': None
'sections': [{'label': 'Changes',
'commits': [{'author': 'John doe',
'body': '',
'subject': 'Adding some extra values.'},
{'author': 'John Doe',
'body': '',
'subject': 'Some more changes'}]},
{'label': 'Other',
'commits': [{'author': 'Jim Foo',
'body': '',
'subject': 'classic modification'},
{'author': 'Jane Done',
'body': '',
'subject': 'Adding some stuff to do.'}]}]},
{'label': 'v0.2.5 (2013-08-06)',
'date': '2013-08-06',
'tag': 'v0.2.5'
'sections': [{'commits': [{'author': 'John Doe',
'body': '',
'subject': 'Updating Changelog installation.'}],
'label': 'Changes'}]}]}


Merged branches history support
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Commit attribution to a specific version could be tricky. Suppose you have
this typical merge tree (spot the tags!)::

* new: something (HEAD, tag: 0.2, develop)
* Merge tag '0.1.1' into develop
|\
| * fix: out-of-band hotfix (tag: 0.1.1)
* | chg: continued development
|/
* fix: something (tag: 0.1)
* first commit (tag: 0.0.1, master)

Here's a minimal draft of gitchangelog to show how commit are
attributed to versions::

0.2
* new: something.
* Merge tag '0.1.1' into develop.
* chg: continued development.

0.1.1
* fix: out-of-band hotfix.

0.1
* fix: something.


.. note:: you can remove automatically all merge commit from
gitchangelog output by using ``include_merge = False`` in the
``.gitchangelog.rc`` file.


Use cases
=========


No sectionning
--------------

If you want to remove sectionning but keep anything else, you should
probably use::

section_regexps = [
('', None)
]

subject_process = (strip | ucfirst | final_dot)

This will disable sectionning and won't remove the prefixes
used for sectionning from the commit's summary.


Incremental changelog
---------------------

Also known as partial changelog generation, this feature allows to generate
only a subpart of your changelog. Usually this makes sense::

- When wanting to switch to ``gitchangelog``, or change your
conventions:
- part of your history is not following conventions.
- you have a previous CHANGELOG you want to blend in.

- You'd rather commit your changelog file:
- For performance reason, you can then generate changelog only for
the new commit and save the result.
- Because you want to be able to edit it to make some minor
edition if needed.

You can use then ``gitchangelog show REVLIST``. Examples follows::

## will output only tags between 0.0.2 (excluded) and 0.0.3 (included)
gitchangelog show 0.0.2..0.0.3

## will output only tags since 0.0.3 (excluded)
gitchangelog show ^0.0.3

## will output all tags up to 0.0.3 (included)
gitchangelog show 0.0.3


Contributing
============

Any suggestion or issue is welcome. Push request are very welcome,
please check out the guidelines.


Push Request Guidelines
-----------------------

You can send any code. I'll look at it and will integrate it myself in
the code base while leaving you as the commit(s) author. This process
can take time and it'll take less time if you follow the following
guidelines:

- check your code with PEP8 or pylint. Try to stick to 80 columns wide.
- separate your commits per smallest concern
- each functionality/bugfix commit should contain the code, tests,
and doc.
- each commit should pass the tests (to allow easy bisect)
- prior minor commit with typographic or code cosmetic changes are
very welcome. These should be tagged in their commit summary with
``!minor``.
- the commit message should follow gitchangelog rules (check the git
log to get examples)
- if the commit fixes an issue or finished the implementation of a
feature, please mention it in the summary.

If you have some questions about guidelines which is not answered here,
please check the current ``git log``, you might find previous commit that
would show you how to deal with your issue. Otherwise, just send your PR
and ask your question. I won't bite. Promise.


License
=======

Copyright (c) 2012-2015 Valentin Lab.

Licensed under the `BSD License`_.

.. _BSD License: http://raw.github.com/vaab/gitchangelog/master/LICENSE

Changelog
=========

2.4.0 (2015-11-10)
------------------

New
~~~

- Add optional positional argument ``REVLIST`` to allow incremental
changelog output (fixes #26) [Valentin Lab]

See use cases documentations for more information.

2.3.0 (2015-09-25)
------------------

Fix
~~~

- Nasty hidden bug that would break python3 (fixes #27) [Valentin Lab]

Actually this bug was revealed by python3 random hashes (thanks to
@rschoon for the hint) and could be reproduced on python2.7 with ``-R``
mode.

The ``git show`` command actually will behave differently if given a tag
reference and print random unexpected information before using the
format string. This would prefix a lot of mess to the first field being
asked in the format string.

And this first field is dependent on the internal order of a dict, and
this order is not important as such, and so nothing was done on this
part.

On python2.7, somehow, it would always be the same order that revealed
to have no consequence (probably one of the rare field not used in
current changelogs).

Python3 or Python2.7 -R would shuffle this order and then trigger the
error whenever this prefix would be appended to actually important
fields that went into some further processing (as casted to int for
the timestamp for instance).

2.2.1 (2015-06-09)
------------------

Fix
~~~

- Fix: doc: ``ìnclude_merge`` options was wrongly typed in sample config
files (reported by @tuukkamustonen, fixed #29). [Valentin Lab]

- Updated doc to reflec that there are no support of windows for now.
(fixes #28) [Valentin Lab]

Actually windows will fail on ``subprocess`` call. (see #28)

- Remove commit's meta-information footer from changelog output. (fixes
#25) [Valentin Lab]

Some various tools (thinking of Gerrit) might leave some
meta-information in the footer of your commit message's body that you do
not want to be repeated in your changelog. So all values in the footer
are removed (This concerns ``Change-Id``, ``Acked-by``, ``CC``,
``Signed-off-by``, ``Bug`` ... and any other value).

2.2.0 (2015-01-27)
------------------

New
~~~

- Provide support for older config file format. [Valentin Lab]

- Added 'octobercms-plugin' mako template. (fixes #16) [Valentin Lab]

- Added ``body_process`` and ``subject_process`` options. (fixes #22)
[Valentin Lab]

These options superseeds ``replace_regexps`` and ``body_split_regexp``
as they provide a full control over text transformation of the subject
or the body of the commit before they get included in the changelog.

- Added ``include_merge`` option to filter out merge commit. [Casey
Duquette]

Changes
~~~~~~~

- Produce a more linear commit history (fixes #14) [Casey Duquette]

Instead of retrieving the git log ordered by date, retrieve the log as
a difference between tags to produce a more accurate view of changes
between releases.

For instance, imagine this git graph::

* 6c0fd62 (HEAD, tag: sprint-6, origin/smoke, smoke, develop)
* 5292a28 Merge back to develop
|\
| * 6612fce (tag: sprint-5.1, origin/master, origin/HEAD, master) super important hotfix
* | 7d6286f more development work
* | 8c1e3d6 continued development work
* | fa3d4bd development work
|/
* ec1a19c (tag: sprint-5)

Previously, commits ``fa3d4bd``, ``8c1e3d6``, ``7d6286f`` that
occurred on the develop branch before the hotfix that led to tagging
``sprint-5.1``, were captured in the changelog under release
``sprint-5.1`` because of the order of the commits. But it is obvious
that these commits were not included in a release until
``sprint-6``. The new method of calculating the changelog will capture
this and reflect it properly, assigning those changes to ``sprint-6``.

Fix
~~~

- Last commit was omitted (fixes #23). [Valentin Lab]

- Bogus messages when template didn't exist. [Valentin Lab]

Refactored out the common code and corrected the bad error message.

- Removed hypothetical memory exhaust while parsing ``git log``.
[Valentin Lab]

Parse stdout as it's produced by git log by chunks.

2.1.2 (2014-04-25)
------------------

Fix
~~~

- Fail with error message when config path exists but is not a file.
(fixes #11) [Casey Duquette]

For example, the config file could be a directory.

2.1.1 (2014-04-15)
------------------

Fix
~~~

- Removed exception if you had file which name that matched a tag's
name. (fixes #9) [Valentin Lab]

2.1.0 (2014-03-25)
------------------

New
~~~

- Python3 compatibility. [Valentin Lab]

- Much greater performance on big repository by issuing only one shell
command for all the commits. (fixes #7) [Valentin Lab]

- Add ``init`` argument to create a full ``.gitchangelog.rc`` in current
git repository. [Valentin Lab]

- Remove optional first argument that could specify the target git
repository to consider. [Valentin Lab]

This is to remove duplicate way to do things. ``gitchangelog`` should be run
from within a git repository.

Any usage of ``gitchangelog MYREPO`` can be written ``(cd MYREPO;
gitchangelog)``.

- Use a standard formatting configuration by default. [Valentin Lab]

A default `standard` way of formatting is used if you don't provide
any configuration file. Additionaly, any option you define in your
configuration file will be added "on-top" of the default configuration
values. This can reduce config file size or even remove the need of
one if you follow the standard.

And, thus, you can tweak the standard for your needs by providing only partial
configuration file. See tests for examples.

- Remove user or system wide configuration file lookup. [Valentin Lab]

This follows reflexion that you build a changelog for a repository and
that the rules to make the changelog should definitively be explicit and
thus belongs to the repository itself.

Not a justification, but removing user and system wide configuration files
also greatly simplifies testability.

Fix
~~~

- Encoding issues with non-ascii chars. [Valentin Lab]

- Avoid using pipes for windows compatibility and be more performant by
avoiding to unroll full log to get the last commit. [Valentin Lab]

- Better support of exotic features of git config file format. (fixes
#4) [Valentin Lab]

git config file format allows ambiguous keys:

[a "b.c"]
d = foo
[a.b "c"]
e = foo
[a.b.c]
f = foo

Are all valid. So code was simplified to use directly ``git config``.
This simplification will deal also with cases where section could be
attributed values:

[a "b"]
c = foo
[a]
b = foo

By avoiding to parse the entire content of the file, and relying on
``git config`` implementation we ensure to remain compatible and not
re-implement the parsing of this file format.

- Gitchangelog shouldn't fail if it fails to parse your git config.
[Michael Hahn]

2.0.0 (2013-08-20)
------------------

New
~~~

- Added a ``mako`` output engine with standard ReSTructured text format
for reference. [Valentin Lab]

- Added some information on path lookup scheme to find
``gitchangelog.rc`` configuration file. [Valentin Lab]

- Added templating system and examples with ``mustache`` template
support for restructured text and markdown output format. [David
Loureiro]

Changes
~~~~~~~

- Removed ``pkg`` and ``dev`` commits from default sample changelog
output. [Valentin Lab]

Fix
~~~

- Some error message weren't written on stderr. [Valentin Lab]

1.1.0 (2012-05-03)
------------------

New
~~~

- New config file lookup scheme which adds a new possible default
location ``.gitchangelog.rc`` in the root of the git repository.
[Valentin Lab]

- Added a new section to get a direct visual of ``gitchangelog`` output.
Reworded some sentences and did some other minor additions. [Valentin
Lab]

Changes
~~~~~~~

- Removed old ``gitchangelog.rc.sample`` in favor of the new documented
one. [Valentin Lab]

Fix
~~~

- The sample file was not coherent with the doc, and is now accepting
'test' and 'doc' audience. [Valentin Lab]

1.0.2 (2012-05-02)
------------------

New
~~~

- Added a new sample file heavily documented. [Valentin Lab]

Fix
~~~

- ``ignore_regexps`` where bogus and would match only from the beginning
of the line. [Valentin Lab]

- Display author date rather than commit date. [Valentin Lab]

0.1.2 (2011-05-17)
------------------

New
~~~

- Added ``body_split_regexp`` option to attempts to format correctly
body of commit. [Valentin Lab]

- Use a list of tuple instead of a dict for ``section_regexps`` to be
able to manage order between section on find match. [Valentin Lab]

Fix
~~~

- ``git`` in later versions seems to fail on ``git config <key>`` with
errlvl 255, that was not supported. [Valentin Lab]

- Removed Traceback when there were no tags at all in the current git
repository. [Valentin Lab]

0.1.1 (2011-04-07)
------------------

New
~~~

- Added section classifiers (ie: New, Change, Bugs) and updated the
sample rc file. [Valentin Lab]

- Added a succint ``--help`` support. [Valentin Lab]