.. _code-submission-guide:

==========================
Code Submission Guidelines
==========================

StarlingX follows the
`OpenStack developer contribution guidelines <https://docs.openstack.org/infra/manual/developers.html>`_.
This guide contains StarlingX-specific tasks and guidelines.

.. contents::
   :local:
   :depth: 2

-------------------------------------
Pre-review and pre-submission testing
-------------------------------------

* For the majority of cases, it is expected that the author completes their
  testing before posting a review.
* Update existing automated unit tests and add new ones when applicable.
* Make sure the new code compiles and builds successfully.
* For each package being modified, update the ``TIS_PATCH_VER`` variable in
  the centos/build_srpm.data. If ``TIS_PATCH_VER=PKG_GITREVCOUNT`` is already present,
  then changes to increment is for testing only; and is not required in commit
  as the version is automatically incremented on commit. This ensures that packages
  are versioned correctly and the latest version will be used. If up-versioning a
  package, then reset ``TIS_PATCH_VER`` to 0.
* Check build dependencies of a new or modified package using
  ``build-pkgs --dep-test <pkg>`` (see details below).
* Run tox tests (flake8, py27, etc) successfully. These can all be run manually
  prior to launching a review.
* Verify basic functional testing on a live system to ensure the new code gets
  executed and functions correctly.
* If the code changes are related to config/stx-puppet/ansible, impact on the following
  should be assessed.  If appropriate, additional tests should be executed.

  * Bootstrap
  * Backup and restore
  * Upgrade
* If needed, consult with the core reviewers or send questions to the StarlingX
  discuss mailing list (starlingx-discuss@lists.starlingx.io) regarding
  required/recommended testing.
* The commit message should include a **Test Plan** section that lists the test case
  titles of manual tests executed on the update. In addition to the success path
  test cases, additional test plan subsections are recommended.
  For example.::

      Test Plan: <success path test cases for new or changed behaviors>

      PASS: Verify new functional behavior 1
      PASS: Verify affected functional behavior 2

      Failure Path: <failure path, i.e. negative tests>

      PASS: Verify feature error path 1 is handled properly
      PASS: Verify feature error path 2 is handled properly
      PASS: Verify feature error path n is handled properly

      Regression: <test cases that should still work but should be confirmed>

      PASS: Verify system install
      PASS: Verify feature alarm handling
      PASS: Verify no core dumps and no memory leaks
      PASS: Verify feature logging

      Notes on the above "Execution Status Key":
          FAIL: test failed; author is investigating while review is in progress
          PASS: test passed
              : no status means the test is not yet run.

  After completing testing, when the code is ready for submission, it's not
  necessary to add expected results.  Just the titles are sufficient.  The
  formatting of the **Test Plan** section must conform to standard commit
  message rules.  The goal is to inform reviewers about the testing done
  as part of this new code.

------------
Code reviews
------------

* Use Gerrit for StarlingX code reviews
* Follow the OpenStack Git Commit Good Practice for
  `Git Commit Messages <https://wiki.openstack.org/wiki/GitCommitMessages>`_
* Add the core reviewers for the affected sub-project to the review, as well as
  any other interested reviewers

  * The core reviewers are listed in each sub-project repository. Refer to the
    list of
    `sub-project repos <https://review.opendev.org/#/admin/groups/?filter=starlingx>`_
  * In order for code to get merged, two core reviewers must give the review +2.
    A final Workflow +1 from one core reviewer will allow the code to merge.
    Typically, the final W+1 is done by the second core reviewer.
  * If a core reviewer sets a -2, the code cannot be merged until that reviewer
    removes their -2.
  * Authors should not review their own code and, therefore, should not +2 or W+
    their code submissions

    * If an exception is needed (ex: emergency fix for a broken build), the
      author should send an email to the mailing list to let the community know
      or contact the core reviewers on IRC.

-------------------
Code review process
-------------------

* Any contributor can review commits by any other contributor, optionally adding
  comments and/or setting approvals of -1/0/+1. For regular contributors, these
  are considered opinion only, though the core reviewers
  will generally take them into account.
* Reviewers should set "-1" to indicate there are things which must be fixed
  before the review should be approved. If a reviewer sets -1, they must leave
  one or more comments indicating specific issues.
* If line-specific issues are raised by a reviewer, it is expected that the
  committer leaves line-specific comments indicating that it has been addressed
  (this could be a simple as replying with "Done"), or if not, why not. General
  comments applying to the whole review should be replied to in the general
  comments.
* Reviewers may prefix comments with "nit:". This indicates a fix that would be
  nice but would not block merging the commit. If a new revision is needed to
  fix any non-nit issues, it is expected that any nits should be fixed at that
  time.
* For more details, refer the OpenStack code review process, documented in the
  `OpenStack Developer Guide <https://docs.openstack.org/infra/manual/developers.html#code-review>`_

.. _link-review-to-story:

----------------------------
Link reviews to story or bug
----------------------------

* For traceability, always link your code change to a story or bug. The
  story/bug will give reviewers context for the code changes. This will also be
  used to help determine the relative priority of the code changes.
* Gerrit will update the status of the story/bug automatically once the code is
  merged.
* Linking to StoryBoard Stories: Specify the story and task ID in the commit
  message as follows:

  * Story: $story_id
  * Task: $task_id
  * Example: https://review.openstack.org/#/c/590083/
* Linking to Launchpad Bugs: Specify the Bug ID in the commit message as
  follows:

  * Closes-Bug: $bug_id -- use 'Closes-Bug' if the commit is intended to fully
    fix and close the bug being referenced.
  * Partial-Bug: $bug_id -- use 'Partial-Bug' if the commit is only a partial
    fix and more work is needed.
  * Related-Bug: $bug_id -- use 'Related-Bug' if the commit is merely related
    to the referenced bug.
  * If a fix requires multiple commits, use "Partial-Bug" with only the final
    commit using "Closes-Bug"
  * Example: https://review.openstack.org/596305

************************
Check build dependencies
************************

When you upversion a package or make significant changes to its build scripts
(spec files, make files, auto-config, etc.), you must test the build
dependencies of the modified package.

First, complete a full build using ``build-pkgs``.

Next, use ``build-pkgs --dep-test <pkg>`` to test the build dependencies.

You may think that if your package passes a full build (``build-pkgs``), that
all dependencies have been checked, however, this is **not** the case. When
doing a full build, the build environment is not wiped clean between packages.
This means that the environment might (or might not) have a tool or library
required by your package, which is not listed as a ``BuildRequires`` in its spec
file. Your package may build successfully one time, but might not build the next
time, depending on which packages were scheduled to build in the same
environment before your package.

The ``--dep-test`` option rebuilds one specific package in a clean environment
and provides an effective test of the BuildRequires for that package.

-------------------------
Early review and feedback
-------------------------

* In specific cases, changes can be posted for early review prior to testing
  (ex: need early feedback on detailed design/coding approach)
* Such changes should be marked as WIP in the commit message and given a
  Workflow -1 immediately by the author
* The author should also include a comment in the review explaining the purpose
  of the review and why the testing is deferred.
* Reviewing code early and often helps catch design and coding errors sooner
  and shows us following the Four Opens.

--------------
Cherry-picking
--------------

* All code changes must be pushed to master first and then cherry-picked to the
  appropriate release branch as needed
* When cherry-picking updates using “git cherry-pick”, include the '-x' option. This
  automatically adds the “(cherry picked from commit XXXXX)” line to your commit
  message, which is helpful to code reviewers.
* Exception: Feature branches used during development

------------
Patch rebase
------------

* During patch re-base, there is a chance that patches can be applied by
  treating the patch line numbers as approximate, rather than a strict
  requirement, just so long as the before/after context seems to be correct.
  They require fuzzing during the patch apply, and an .orig file will be
  created as the consequence of applying patches that are not clean.

* In StarlingX, we will not accept fuzzing patches. All patches are required to
  be re-based cleanly so that no fuzzing and no .orig files are generated.