OpenJFX code review policies, etc.
kevin.rushforth at oracle.com
Wed May 23 22:16:49 UTC 2018
To: OpenJFX Developers
As I mentioned in a message last week  I would like to restart the
discussion we started a few months ago  around making it easier to
contribute code to OpenJFX. To this end, I like to make some concrete
proposals around code review / API review policies.
Before getting to the details, I would like to acknowledge Gluon's
contributions to the OpenJFX project, specifically those of Johan Vos. I
am pleased to announce an expanded role for Johan Vos in the OpenJFX
project. I would like to announce that starting now, Johan is
effectively a co-lead for the purposes of setting direction, and
approving new features for the Project.
The short version of the proposal is:
1. Formalize the concept of Reviewers with an initial list of Reviewers
and a defined criteria for adding additional Reviewers.
2. Revised code review policies for different types of changes: simple,
low-impact fixes (1 Reviewer); higher-impact fixes (2 Reviewers + allow
time for others to chime in); Features / API changes (CSR approval,
including approval by a "lead", plus 3 Reviewers for the code)
3. Streamlining reviews of changes developed in the GitHub sandbox:
provided that the review policy is followed to before a PR is merged
into the develop branch in GitHub, a fast-track review can happen
pointing to the changeset that was merged and the PR, which has review
Quoting from my earlier message:
> "Code reviews are important to maintain high-quality contributions,
> but we recognize that not every type of change needs the same level of
> review. Without lowering our standards of quality, we want to make it
> easier to get low-impact changes (simple bug fixes) accepted."
To that end, I propose the following policies. Many of these will
involve judgment calls, especially when it comes to deciding whether a
fix is low impact vs. high-impact. I think that's OK. It doesn't have to
1. I recommend that we formalize the concept of Reviewers, using the
OpenJDK Reviewer role for the OpenJFX Project.
A. I will provide an initial list of reviewers to the registrar based on
past contributions, and also recognizing Committers who have become
experts in their area. This is the only time we will have such latitude
as the OpenJDK Bylaws specify the policy we need to follow for
nominating and voting upon additional Reviewers.
B. We need to set formal guidelines for becoming a Reviewer. The JDK
uses a threshold of 32 significant contributions. While we don't want to
relax it too much, one thing I have been discussing informally with a
few people is that a Committer with, say, 24 commits, who regularly
participates in reviews, offering good feedback, might be just a good a
reviewer (maybe even better) than someone with 32 commits who rarely, if
ever, provides feedback on proposed bug fixes. I'm open for suggestions
One thing I'd like to add is that we expect Reviewers to feel
responsible not just for their piece, but for the quality of the JavaFX
library as a whole. I might work with some folks at Gluon and here at
Oracle to draft a set of expectations for reviewers.
2. Code review policies
All code reviews must be posted on the openjfx-dev mailing list -- even
simple fixes. I propose that we have the following code review policies
for different types of changes. I also note that if there is
disagreement as to whether a fix is low-impact or high-impact, then it
is considered high-impact. In other words we will always err on the side
of quality by "rounding up" to the next higher category. The contributor
can say whether they think something is low-impact or high-impact, but
It is up to a Reviewer to initially decide this.
A. Low-impact bug fixes. These are typically isolated bug fixes with
little or no impact beyond fixing the bug in question; included in this
category are test fixes (including new tests), doc fixes, and fixes to
sample applications (including new samples).
One reviewer is sufficient to accept such changes. As a courtesy, and to
avoid changes which later might need to be backed out, if you think
there might be some concern or objection to the change, please give
sufficient time for folks who might be in other time zones the chance to
take a look. This should be left up to the judgment of the reviewer who
approves it as well as the contributor.
B. Higher impact bug fixes or RFEs. These include changes to the
implementation that potentially have a performance or behavioral impact,
or are otherwise broad in scope. Some larger bug fixes will fall into
this category, as will fixes in high-risk areas (e.g., CSS).
Two reviewers must approve to accept such changes. Additionally, the
review should allow sufficient time for folks who might be in other time
zones the chance to review if they have concerns.
C. New features / API additions. This includes behavioral changes,
additions to the fxml or css spec, etc.
Feature requests come with a responsibility beyond just saying "here is
the code for this cool new feature, please take it". There are many
factors to consider for even small features. Larger features will need a
significant contribution in terms of API design, coding, testing,
To ensure that new features are consistent with the rest of the API and
the desired direction of the Project, I propose that a New Feature, API
addition, or behavioral change must be reviewed / approved by a "lead".
Currently this is either myself or Johan Vos as indicated above.
I also propose that we continue to use the CSR process  to track such
changes. The CSR chair has indicated that he is willing to track JavaFX
compatibility changes even though FX is no longer a part of the JDK.
For the review of the implementation, I propose that we use the same
"two reviewer" standard for the code changes as category B.
3. Streamlining the review process for changes developed on GitHub
A fix that was developed as pull-requests (PRs) on GitHub is eligible
for a fast-track review, if:
A. The PR was squashed / merged into the develop branch as a single
B. No follow-on changesets were merged into develop as part of that same fix
C. The changeset is "whitespace clean" -- meaning that you have run
'tools/scripts/checkWhiteSpace' on the final changeset (we might want to
add this to the CI build).
D. All code review policies outlined above in #2 were followed prior to
the PR being approved and merged into the develop branch on GitHub. This
includes sending email to openjfx-dev when you first make a PR that you
intend to have merged into the develop branch to give other reviewers
who may not be watching all PRs a chance to comment before it is merged.
A "fast-track" review is a quick sanity check before the change is
committed and pushed to the jfx-dev repo on hg.openjdk.java.net. This
fast track review just needs to point to the GitHub changeset that was
merged and to the PR, which will have any review comments. If there are
no compelling reasons why the PR can't be pushed to jfx-dev, then it can
Please let me know your thoughts on the above proposals.
Thank you all for being a part of this community.
-- Kevin Rushforth, OpenJFX Project Lead
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