Suggestion for CI: Only run on push to master OR pull request

[junderw]

I was noticing that a lot of internal PRs (made by team members) were firing multiple CIs for push and pull_request.

In BitcoinJS we use the following.

on:
  push:
    branches:
      - master
  pull_request:

I have also considered adding a pattern matching for branches with the prefix with-ci/** (edit: looked up the actual syntax) in case we want to test the CI internally before making a PR... but in general we've just tested things out on PRs anyways so never needed it.

Any thoughts?

[Kixunil]

Yeah, I'd prefer for pull request since we want to see test status in them but could get annoying if people want to test something on their own branch without bothering us.

[apoelstra]

Would this mean that we don't re-run CI when PRs get updated?

[junderw]

Yeah, I'd prefer for pull request since we want to see test status in them but could get annoying if people want to test something on their own branch without bothering us.

@Kixunil This can be done by having some sort of branch prefix or special branch. The above syntax is basically an array in yaml, so you could do multiple filters for deciding which branches will run a CI: See here

on:
  push:
    branches:
      - master
      - special-branch # this will also run CI on the special-branch branch
      - 'use-ci/**' # this will run CI on any branch that starts with use-ci/
  pull_request:

Would this mean that we don't re-run CI when PRs get updated?

@apoelstra CI will be re-run with every push to an open PR branch regardless of whether the branch is internal or external.

You can verify this behavior in a recent PR on our repo: bitcoinjs/bitcoinjs-lib#1879 (edit: and also here bitcoinjs/bitcoinjs-lib#1859 which uses an external branch not named master on the external fork, I didn't approve the CI to run until he fixed a few things, but you can see two pushes the author made both running CI)

Scrolling down the comments, the 3 commits all ran CI with the above (in OP) configuration.

[apoelstra]

Ok, cool, I think I understand. This does seem like a good idea.

[junderw]

I opened a PR for your review.