Merge pull request #100 from astropy/policies-pr-review

Add policy on pull request review and merge

Author: eteq

policies/pull-request-review-and-merge.md

@@ -0,0 +1,88 @@
+# Astropy Project Pull Request Review & Merging Policy
+
+## Astropy Core Package
+
+When submitting a pull request (PR) in the Astropy core package the following
+process must take place before it can be accepted. If the pull request fails any
+of the reviews or checks it must be amended and undergo additional review before
+being accepted.
+
+### Review & Approval
+
+All pull requests will be reviewed by at least one contributor with relevant
+expertise to ensure that:
+
+  - New or updated code is correct and achieves the desired effect of
+    either fixing a bug or making an enhancement.
+  - New tests or modifications to tests are adequate to cover the code changes.
+    Tests for edge cases exist where applicable and judged to be sufficiently
+    important.
+  - There are no API changes or the API changes are well-understood and
+    acceptable and beneficial on the whole to the Astropy user community, and
+    are documented as an API change in the changelog.
+  - Formatting and style maintain the existing style of a package and
+    readability of the code base for future developers.
+
+Reviews will be detailed and should include review and suggestions at the
+line-by-line level, although "I looked and had no comments" is a valid answer
+
+For pull requests that require specific knowledge of a sub-package, a maintainer
+of the sub-package that the contribution affects is required to approve. For
+other less complex cases, for example a documentation improvement, review may be
+conducted by any Astropy core package maintainer.
+
+While a core package maintainer does not have to be the one performing the
+review, if the review is performed by someone else, that maintainer is
+responsible for ensuring the contributor review is sufficiently detailed and
+follows these guidelines.
+
+After successful review, the maintainer(s) will formally approve the pull
+request.
+
+### Additional Checks
+
+Additional checks will be performed to verify that there are no other issues
+with the pull request, for example:
+
+- A release manager or maintainer will check that the selected release milestone
+  is suitable for the scope of the change.  In particular bug-fix backports are
+  considered where feasible and sensible. Documentation is usually backported.
+  API changes or new feature changes are not backported unless under special
+  circumstances.
+- A matrix of CI checks will be run to ensure that all existing tests pass on
+  supported platforms. Even CI jobs that are allowed to fail should still pass
+  unless a known and unrelated failure occurs; i.e., look at the logs even in
+  the event of a green check mark.
+- An automated tool will check that the change log mentions the change and PR
+  number and that the change log section used matches the selected release
+  milestone set by the maintainer.
+
+### Merging
+
+The pull request will be merged once it is approved by relevant maintainers (as
+described above) and has passed all necessary checks. This can be done by any
+core package maintainer. In practice this is sometimes the PR developer and
+sometimes the reviewer.
+
+## Astropy Coordinated & Infrastructure Packages
+
+The process of PR approval for coordinated and infrastructure packages should be
+the same as the process for the core package except that reviews and approvals
+can be done by any maintainer. Coordinated and infrastructure packages should
+have at least two maintainers with push access and all PRs should be approved by
+at least one of the other maintainers. Any maintainer can then merge the pull
+request once it is approved.
+
+## Astropy Affiliated Packages
+
+The change process for affiliated packages is largely at the discretion of the
+package maintainers. Affiliated packages may make their requirements as rigorous
+or as lenient as they like. However, the Astropy Project does require that
+affiliated packages maintain the code under version control on a publicly
+available site.
+
+In most cases packages are hosted on GitHub or GitLab and updated via pull
+requests, but this is not a requirement. Independent review is encouraged but is
+at the discretion of the package maintainer(s) as some packages may be largely
+developed by a single maintainer. Please see the affiliated package’s
+documentation for more information.