3.6. Core Committer

Core committers (or simply, committers) are responsible for reviewing pull requests from contributors. This happens once the pull request has passed through a community manager and been prioritized by a product owner. As much as possible, the code review process for community contributors should be identical to the process of reviewing a pull request from another committer: we’re all part of the same community. However, there are a few ways that the process is different:

  • The contributor cannot see when conflicts occur in the branch. These conflicts prevent the pull request from being merged, so you should ask the contributor to rebase their pull request, and point them to the documentation for doing so.
  • Jenkins may not run on the contributor’s pull request automatically. Be sure to start new Jenkins jobs for the PR as necessary – do not approve a pull request unless Jenkins has run, and passed, on the last commit in the pull request. If this contributor has already contributed a few good pull requests, that contributor can be added to the Jenkins whitelist, so that jobs are run automatically.
  • The contributor may not respond to comments in a timely manner. This is not your concern: you can move on to other things while waiting. If there is no response after a few days, a community manager will warn the contributor that if the comments are not addressed, the pull request will be closed. (You can also warn the contributor yourself, if you wish.) Do not close the pull request merely because the contributor hasn’t responded. If you think the pull request should be closed, inform the community managers, and they will handle it.

Each Scrum team should decide for themselves how to estimate stories related to reviewing external pull requests, and how to claim points for those stories, keeping in mind that an unresponsive contributor may block the story in ways that the team can’t control. When deciding how many contributor pull request reviews to commit to in the upcoming iteration, teams should plan to spend about two hours per week per developer on the team – larger teams can plan to spend more time than smaller teams. For example, a team with two developers should plan to spend about four hours per week on pull request review, while a team with four developers should plan to spend about eight hours per week on pull request review – these hours can be spread out among multiple developers, or one developer can do all the review for the whole team in that iteration. However, this is just a guideline: the teams can decide for themselves how many contributor pull request reviews they want to commit to.

Once a pull request from a contributor passes all required code reviews, a core committer will need to merge the pull request into the project. The core committer who merges the pull request will be responsible for verifying those changes on the staging server prior to release, using the manual test plan provided by the author of the pull request.

In addition to reviewing contributor requests as part of sprint work, core committers should expect to spend about one hour per week doing other tasks related to the open source community: reading/responding to questions in the Community Discussions , disseminating information about what edX is working on, and so on.

3.6.1. Review Comments Terminology

In order to expedite the review process and to have a clear and mutual understanding between reviewers and contributors, the following terminology should be used when submitting comments on a PR:

  • Must - A comment of type “Must” indicates the reviewer feels strongly about their requested change to the code and feels the PR should not be merged unless their concern is satisfactorily addressed.
  • Opt(ional) - A comment of type “Optional” indicates the reviewer strongly favors their suggestion, but may be agreeable to the current behavior, especially with a persuasive response.
  • Nit(pick) - A comment of type “Nitpick” indicates the reviewer has a minor criticism that might not be critical to address, but considers important to share in the given context. Contributors should still seriously consider and weigh these nits and address them in the spirit of maintaining high quality code.
  • FYI - A comment of type “FYI” is a related side comment that is informative, but with the intention of having no required immediate action.

As an example, the following PR comment is clearly categorized as Optional:

"Optional: Consider reducing the high degree of connascense in this code by using keyword arguments."


It is possible that after further discussion and review, the reviewer chooses to amend their comment, thereby changing its severity to be higher or lower than what was originally set.