Playground PR Previews as a GitHub App or a generic GitHub action

[adamziel]

Let's make the automatic "PR Preview" comment easy to integrate with any repo:

Currently it's a custom wordpress-develop GitHub workflow. It should be reusable with some manual copy&paste&adjust work. I'd love to turn it into a GitHub App that could be installed in any repo and configured with an artifact name and a default message. It would help many WordPress ecosystem projects.

Here's some inspiration to reuse:

• Docs: How to add Pull Request previews to your repository? #1237
• Pull Request previewer for all WordPress projects #696
• Auto-post a Playground preview link on every PR gutenberg#60795
• https://github.com/Automattic/themes/blob/trunk/.github/workflows/preview-theme.yml
• https://github.com/WordPress/blueprints/blob/trunk/.github/workflows/preview-comment.yml

cc @ockham @ndiego

[ndiego]

Over the weekend, I was experimenting with Playground blueprints for my personal repos (Icon Block example). I modified a shields.io badge for "Playground Demo" and then linked it to the blueprint in the repo. I like the way it turned out, but a more standardized approach would be cool.

[ockham]

Love it!

I'd love to turn it into a GitHub App that could be installed in any repo and configured with an artifact name and a default message.

My first guess was actually to extract a reusable GitHub Action (which is arguably lower-level and would likely require users to be a bit more experienced). I haven't worked with GH Apps really; is it reasonable to assume that we'd need the action anyway, and the app would be built around it?

[adamziel]

@ockham I'm not sure actually! But a reusable action would also go a long way. A GitHub App is an implementation detail, a GitHub link to start a new PR that adds a new yml workflow would be just as good.

[adamziel]

@vcanales created a reusable GitHub action here: vcanales/action-wp-playground-pr-preview 🎉 I've filed a few issues that would get us where this issue intended:

• Customizable parameters action-wp-playground-pr-preview#12
• Move under the WordPress GitHub organization action-wp-playground-pr-preview#13
• Mode switcher: New comment vs updating the issue description action-wp-playground-pr-preview#14

[vcanales]

@adamziel thanks for creating the issues! Making the action more flexible was definitely in my radar, and this is a great roadmap for that.

[adamziel]

There's now a GitHub action for this available in an official WordPress repository: https://github.com/WordPress/action-wp-playground-pr-preview

Let's still keep this issue open until:

• That action can handle plugins, not just themes
• That action is easy to find for anyone interested in previewing their WordPress PRs – this could involve Playground docs, blog posts, and even in-Playground links and integrations such as "set up PR previews for your repo" link. CC @akirk @bph.