First read the overall project contributing guidelines. These are all included in the qiskit documentation:
https://qiskit.org/documentation/contributing_to_qiskit.html
In addition to the general guidelines there are specific details for contributing to ignis, these are documented below.
When submitting a pull request and you feel it is ready for review, please ensure that:
- The code follows the code style of the project and successfully
passes the tests. For convenience, you can execute
toxlocally, which will run these checks and report any issues. - The documentation has been updated accordingly. In particular, if a function or class has been modified during the PR, please update the docstring accordingly.
- If it makes sense for your change that you have added new tests that cover the changes.
- Ensure that if your change has an end user facing impact (new feature, deprecation, removal etc) that you have added a reno release note for that change and that the PR is tagged for the changelog.
The changelog is automatically generated as part of the release process
automation. This works through a combination of the git log and the pull
request. When a release is tagged and pushed to github the release automation
bot looks at all commit messages from the git log for the release. It takes the
PR numbers from the git log (assuming a squash merge) and checks if that PR had
a Changelog: label on it. If there is a label it will add the git commit
message summary line from the git log for the release to the changelog.
If there are multiple Changelog: tags on a PR the git commit message summary
line from the git log will be used for each changelog category tagged.
The current categories for each label are as follows:
| PR Label | Changelog Category |
|---|---|
| Changelog: Deprecation | Deprecated |
| Changelog: New Feature | Added |
| Changelog: API Change | Changed |
| Changelog: Removal | Removed |
| Changelog: Bugfix | Fixed |
When making any end user facing changes in a contribution we have to make sure we document that when we release a new version of qiskit-aer. The expectation is that if your code contribution has user facing changes that you will write the release documentation for these changes. This documentation must explain what was changed, why it was changed, and how users can either use or adapt to the change. The idea behind release documentation is that when a naive user with limited internal knowledege of the project is upgrading from the previous release to the new one, they should be able to read the release notes, understand if they need to update their program which uses qiskit, and how they would go about doing that. It ideally should explain why they need to make this change too, to provide the necessary context.
To make sure we don't forget a release note or if the details of user facing changes over a release cycle we require that all user facing changes include documentation at the same time as the code. To accomplish this we use the reno tool which enables a git based workflow for writing and compiling release notes.
Making a new release note is quite straightforward. Ensure that you have reno installed with::
pip install -U reno
Once you have reno installed you can make a new release note by running in your local repository checkout's root::
reno new short-description-string
where short-description-string is a brief string (with no spaces) that describes what's in the release note. This will become the prefix for the release note file. Once that is run it will create a new yaml file in releasenotes/notes. Then open that yaml file in a text editor and write the release note. The basic structure of a release note is restructured text in yaml lists under category keys. You add individual items under each category and they will be grouped automatically by release when the release notes are compiled. A single file can have as many entries in it as needed, but to avoid potential conflicts you'll want to create a new file for each pull request that has user facing changes. When you open the newly created file it will be a full template of the different categories with a description of a category as a single entry in each category. You'll want to delete all the sections you aren't using and update the contents for those you are. For example, the end result should look something like::
features:
- |
Introduced a new feature foo, that adds support for doing something to
``QuantumCircuit`` objects. It can be used by using the foo function,
for example::
from qiskit import foo
from qiskit import QuantumCircuit
foo(QuantumCircuit())
- |
The ``qiskit.QuantumCircuit`` module has a new method ``foo()``. This is
the equivalent of calling the ``qiskit.foo()`` to do something to your
QuantumCircuit. This is the equivalent of running ``qiskit.foo()`` on
your circuit, but provides the convenience of running it natively on
an object. For example::
from qiskit import QuantumCircuit
circ = QuantumCircuit()
circ.foo()
deprecations:
- |
The ``qiskit.bar`` module has been deprecated and will be removed in a
future release. Its sole function, ``foobar()`` has been superseded by the
``qiskit.foo()`` function which provides similar functionality but with
more accurate results and better performance. You should update your calls
``qiskit.bar.foobar()`` calls to ``qiskit.foo()``.You can also look at other release notes for other examples.
You can use any restructured text feature in them (code sections, tables, enumerated lists, bulleted list, etc) to express what is being changed as needed. In general you want the release notes to include as much detail as needed so that users will understand what has changed, why it changed, and how they'll have to update their code.
After you've finished writing your release notes you'll want to add the note
file to your commit with git add and commit them to your PR branch to make
sure they're included with the code in your PR.
After release notes have been added if you want to see what the full output of
the release notes. In general the output from reno that we'll get is a rst
(ReStructuredText) file that can be compiled by
sphinx. To generate the rst file you
use the reno report command. If you want to generate the full aer release
notes for all releases (since we started using reno during 0.9) you just run::
reno report
but you can also use the --version argument to view a single release (after
it has been tagged::
reno report --version 0.5.0
At release time reno report is used to generate the release notes for the
release and the output will be submitted as a pull request to the documentation
repository's release notes file
Building The release notes are part of the standard qiskit-aer documentation
builds. To check what the rendered html output of the release notes will look
like for the current state of the repo you can run: tox -edocs which will
build all the documentation into docs/_build/html and the release notes in
particular will be located at docs/_build/html/release_notes.html
Please see the Installing Qiskit Ignis from Source section of the Qiskit documentation.
Once you've made a code change, it is important to verify that your change does not break any existing tests and that any new tests that you've added also run successfully. Before you open a new pull request for your change, you'll want to run the test suite locally.
The easiest way to run the test suite is to use
tox. You can install tox
with pip: pip install -U tox. Tox provides several advantages, but the
biggest one is that it builds an isolated virtualenv for running tests. This
means it does not pollute your system python when running. Additionally, the
environment that tox sets up matches the CI environment more closely and it
runs the tests in parallel (resulting in much faster execution). To run tests
on all installed supported python versions and lint/style checks you can simply
run tox. Or if you just want to run the tests once run for a specific python
version: tox -epy37 (or replace py37 with the python version you want to use,
py35 or py36).
If you just want to run a subset of tests you can pass a selection regex to
the test runner. For example, if you want to run all tests that have "dag" in
the test id you can run: tox -epy37 -- dag. You can pass arguments directly to
the test runner after the bare --. To see all the options on test selection
you can refer to the stestr manual:
https://stestr.readthedocs.io/en/stable/MANUAL.html#test-selection
If you want to run a single test module, test class, or individual test method
you can do this faster with the -n/--no-discover option. For example:
to run a module:
tox -epy37 -- -n test.test_examples
or to run the same module by path:
tox -epy37 -- -n test/test_examples.py
to run a class:
tox -epy37 -- -n test.test_examples.TestPythonExamples
to run a method:
tox -epy37 -- -n test.test_examples.TestPythonExamples.test_all_examples
To enforce a consistent code style in the project we use
Pylint and
pycodesytle
to verify that code contributions conform respect the projects
style guide. To verify that your changes conform to the style
guide you can run: tox -elint
The development cycle for qiskit-ignis is all handled in the open using the project boards in Github for project management. We use milestones in Github to track work for specific releases. The features or other changes that we want to include in a release will be tagged and discussed in Github. As we're preparing a new release we'll document what has changed since the previous version in the release notes and Changelog.
master:
The master branch is used for development of the next version of qiskit-ignis. It will be updated frequently and should not be considered stable. The API can and will change on master as we introduce and refine new features.
stable/*: The stable branches are used to maintain the most recent released versions of qiskit-ignis. It contains the versions of the code corresponding to the minor version release in the branch name release for The API on these branches are stable and the only changes merged to it are bugfixes.
From time to time, we will release brand new versions of Qiskit Terra. These are well-tested versions of the software.
When the time for a new release has come, we will:
- Create a new tag with the version number and push it to github
- Change the
masterversion to the next release version.
The release automation processes will be triggered by the new tag and perform the following steps:
- Create a stable branch for the new minor version from the release tag
on the
masterbranch - Build and upload binary wheels to pypi
- Create a github release page with a generated changelog
- Generate a PR on the meta-repository to bump the terra version and meta-package version.
The stable/* branches should only receive changes in the form of bug
fixes.