Wait for app initialization until rendering component

[jbchr]

Description
Angular TestBed is not honoring APP_INITIALIZER contract. This means tests are executed before app initialization is finished. The corresponding Angular issue is this one: angular/angular#24218

In a scenario without testing-library we can easily use a workaround in waiting for the initialization before executing our tests.

await TestBed.get(ApplicationInitStatus).donePromise;

However when using testing-libraries render function we cannot do so, as the lib immediately renders the component after setting up the TestBed

Proposed solution
Insert the above line after setting up the TestBed here:
https://github.com/testing-library/angular-testing-library/blob/master/projects/testing-library/src/lib/testing-library.ts#L76

I'm happy to create a small PR for that :)

[timdeschryver]

Thanks for opening this issue! I wasn't aware of this behavior.
It would be great if you'd create a PR for this 👍

[github-actions]

🎉 This issue has been resolved in version 10.3.1 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀