Document how to consume Theia from a git commitish in downstream projects

[kittaakos]

Feature Description:

As a consumer of Theia, I would like to try out bleeding edge changes in downstream projects. For example, #12932 makes the language contribution lazy. It would be fantastic if there was dev documentation I could use to clone Theia, check out a git hash, and build my downstream project with unreleased/unmerged Theia behavior.

Having a dev doc with some yarn link magic would be sufficient as a first step.

As a pipe dream, a bot could be involved to start an npm publish on request from a PR. Downstream, switching to the target version without any npm/yarn link magic would be sufficient. With the above example PR, 1.42.0+pr-12932 (or similar) could be published to the npm registry.

Thank you!

CC: @marcdumais-work, @tsmaeder

[JonasHelming]

@jfaltermeier FYI

[marcdumais-work]

Hi @kittaakos ,

I am not sure if this is the best way to proceed, but it's possible to build theia at an arbitrary commit and publish it to a local npm registry (Verdaccio), and then build a Theia-based application, using the local registry. Any dependency that's not in the local registry will be fetched from the upstream one. I have only tried this on Linux.

See this PR's "how to test" section to get a description how this can be done:

#11738

[tsmaeder]

The "traditional" way would be to yarn link the the Theia packages in the source tree and to yarn link <package> in the source tree of the application being built. I once had an addition to the theia build script that did this. Maybe there's an old PR.

[kittaakos]

npm registry (Verdaccio

Thank you, @marcdumais-work. Yes, I know it—we used to use it downstream.

Maybe there's an old PR.

It would be helpful if you could look it up, @tsmaeder. I can move it to the dev docs.

[tsmaeder]

@kittaakos unfortunately, it looks like that code was left behind on some Red Hat machine when I left the company 🤷