Detect merge queue branch and retrieve real branch name from pull request

[JonathanKolnik]

If the branch matches the merge queue branch pattern, we extract the pull request number from the branch name and query the index for the PRs actual branch name. We then use that for the rest of the build process.

This depends on a change to the index that allows headRefName to be read via the app code https://github.com/chromaui/chromatic/pull/8128

📦 Published PR as canary version: 10.2.3--canary.884.7542729719.0

✨ Test out this PR locally via:

npm install [email protected]
# or 
yarn add [email protected]

[JonathanKolnik]

@ethriel3695 looks like you managed to get a merge queue test scenario, could you show me how to do so and if you have time, test this canary too? Thanks!

[ethriel3695]

@JonathanKolnik
Of course!

https://github.com/chromaui/vite-project/pull/6/files

I changed the GitHub action in my test repo to use the Chromatic script instead of the GitHub Action.
I changed the version of Chromatic in the package.json to point to the Canary version.

From there, I changed some styles in one of the components and created a PR.
I created another branch directly from my branch, changed some styles in a different component, and created a PR.

Then, I merged both PRs into the merge queue.

Logs in place told me the CI branch from the merge queue.

I'll test on this Canary version too.

[ethriel3695]

@JonathanKolnik
It looks like it worked.

https://www.staging-chromatic.com/build?appId=6567827ff5eb53d578159b6a&number=32
https://www.staging-chromatic.com/build?appId=6567827ff5eb53d578159b6a&number=33

No baselines were detected on either of these merges because the merge queue builds are aware of the previously accepted baseline.

The one thing I'm unclear on is it doesn't look like the branch name changed at all.
https://github.com/chromaui/vite-project/actions/runs/7494123452/job/20401335868
https://github.com/chromaui/vite-project/actions/runs/7494168482/job/20401474600

[ethriel3695]

@JonathanKolnik
On this one, I would feel better if @tmeasday or @ghengeveld can give a second approval.

[tmeasday]

This seems right to me!

[ghengeveld]

🚀 PR was released in v10.3.0 🚀