Set CI_BRANCH_BASE for GitHub Actions

[XhmikosR]

Do you want to request a feature or report a bug?

Bug

What is the current behavior?

There's no way to diff against a branch other than master on GitHub Actions CI

If the current behavior is a bug, please provide the steps to reproduce.

https://github.com/twbs/bootstrap/tree/v4-dev

What is the expected behavior?

If this is a feature request, what is motivation or use case for changing the behavior?

Please mention other relevant information such as the browser version, Node.js version, bundlewatch version, and Operating System.

Recently I switched bootstrap from bundlesize to bundlewatch and it works quite well!

I wanted to figure out how to diff against a branch other than master, in our case v4-dev. I couldn't find how to make this work with GitHub Actions, since the env variables don't seem to provide a similar variable to CI_BRANCH_BASE

Does anybody have any ideas?

[XhmikosR]

After talking to GitHub support and after doing some more searching it appears GitHub sets both github.head_ref and github.base_ref on pull requests.

This could simplify things in

bundlewatch/src/app/config/getCIVars.js

Lines 35 to 36 in 88892bf

	// GitHub only provides ref (read more: https://stackoverflow.com/q/1526471)
	repoCurrentBranch = env.GITHUB_REF.replace(/^refs\/heads\//, '')

...and also allow to use set repoBranchBase.

I don't know if this will fix my issue with our v4-dev branch where bundlewatch is always comparing against master. Maybe I need to set trackBranches only to v4-dev in the v4-dev branch?

[iamogbz]

Looks like github.head_ref and github.base_ref are only set on forked repos https://help.github.com/en/actions/configuring-and-managing-workflows/using-environment-variables

However you should be able to manually set the CI_BRANCH_BASE environment variable to the branch you want to compare against.

[XhmikosR]

@iamogbz thanks for the reply!

I can set the environment variable for the v4-dev branch, but since GitHub does provide a way to do this automatically, the code should take this into account, like it does with Travis and the other CI systems.

If I set the environment variable do I also need to change the trackBranches config not to include master in the v4-dev branch?

[XhmikosR]

Setting the var works. I didn't change trackBranches.

Anyway, I still think it'd be a nice improvement if bundlewatch detected this automatically like it happens with Travis.

[iamogbz]

@XhmikosR glad it worked for now. Will look into getting to work for github actions as well as other CI.
Open to PRs as well.

[iamogbz]

Will replace the getCIVars with npm

• env-ci when this is closed Github Action incorrect behavior semantic-release/env-ci#96
• ci-env when this is closed Add base_branch to exported envs siddharthkp/ci-env#34

[XhmikosR]

I think it's just a couple of lines to add in the current code, though? Don't get me wrong, I also don't like reinventing the wheel, but in the meantime this should do the job 🙂

[XhmikosR]

@iamogbz so, I tried this without setting the CI_BRANCH_BASE variable for a branch based on our v4-dev, but the comparison is wrong, i.e. bundlewatch compares with master. I will add back the variable, I just wanted to let you know, because the issue was closed.

[iamogbz]

@XhmikosR strange! Do you mind providing more details on your ci logs in the case you're able to reproduce.

[XhmikosR]

@iamogbz it seems it's actually broken completely now even for master, but I'm not sure if something else changed: https://github.com/twbs/bootstrap/pull/30814/checks?check_run_id=673413078#step:8:11

For v4-dev without specifying the env var: https://github.com/twbs/bootstrap/runs/659104517?check_suite_focus=true#step:16:1

[iamogbz]

@XhmikosR

For v4-dev without specifying the env var: twbs/bootstrap/runs/659104517?check_suite_focus=true#step:16:1

Do you have a pull request for that? Since github only set the env vars for PRs

[iamogbz]

@XhmikosR

it seems it's actually broken completely now even for master, but I'm not sure if something else changed: #30814 (checks)

Caused by dependency update in bundlewatch service resolved now

[XhmikosR]

@iamogbz that was in a PR against the v4-dev branch, but I dropped the patch after I noticed it didn't work.

Caused by dependency update in bundlewatch service resolved now

Thanks!