feat: add @bazel/angular package

[alexeagle]

This provides a very small shim builder, which spawns the Bazel build tool under an ng build or ng test command.
It can be useful during a migration, where developers use Angular CLI but some parts of the workspace build and test with Bazel.

It is moving from https://github.com/bazelbuild/rules_nodejs/tree/stable/packages/angular
because that project is cutting scope.

PR Checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

Feature

What is the current behavior?

Issue Number: #1047

What is the new behavior?

See added README

Does this PR introduce a breaking change?

No

Other information

[alexeagle]

@just-jeb could you help fit this new code into your lerna model for build and release?

@alan-agius4 can probably help upgrade it to Angular 12 so it is version-aligned with the other builders in here

[just-jeb]

Hey @alexeagle, I'll do the upgrade, no problem.
Are there any tests (e2e o UT) that can be added? Example app, to validate the flow? Any open issues that should be moved here as well?

[just-jeb]

Also, can I have write access to the repo so that I could push to this PR please?

[alexeagle]

Sure, I invited you to that repo with write access. I'm surprised my usual GitHub settings for "Allow edits by project maintainers" didn't apply here to give you push access to that branch automatically.

Nope no open issues for this code, and also no automated tests. It's a very simple bit of glue, which hasn't changed since we added it. Also, since it doesn't have any conditional logic, it's not very unit-testable. I could imagine an integration test if that's important to you.

[just-jeb]

Well I was thinking about a simple Angular app (even the auto generated one) with Bazel config that uses this builder, just to have a regression test and make sure I'm not breaking anything.
Alas I don't have much experience with Bazel, so if you just added such an app here (under examples directory, just like the other builders) or alternatively pointed me out to an example that I can copy, this would be great.

[alexeagle]

Here's an old example that uses this builder
https://github.com/angular/angular-bazel-example/blob/master/angular.json

Note that to test this, there's no need to even have an angular app. We just want to run ng build and have bazel perform some simple action like write a file containing "hello world" or something.

[alexeagle]

I added a commit with a bit of bare files. Didn't try adding a package.json in there yet - I'm not sure how much fixture is required to make your monorepo e2e test runner work here.

[alan-agius4]

Thanks @just-jeb for accepting to add this in your repo and thanks @alexeagle for porting this.

If anyone needs helps feel free to reach out 😁

[just-jeb]

@all-contributors please add @alexeagle for code.

[allcontributors]

@just-jeb

I've put up a pull request to add @alexeagle! 🎉

[just-jeb]

@all-contributors please add @alan-agius4 for code.

[allcontributors]

@just-jeb

I've put up a pull request to add @alan-agius4! 🎉

[just-jeb]

@Mawi137 Hey, I'm sorry, how is that related to @angular-builders in general and to @angular-builders/bazel in particular?

[Mawi137]

Ah sorry, must have thought that this was the Angular 13 issue 😅