Handle errors in ApproximateTerrainHeight.initialize

[jjhembd]

Description

This PR catches errors from ApproximateTerrainHeight.initialize and throws them as DeveloperErrors. This is to avoid erratic behavior when the promise is rejected.

When running tests locally on the webgl stub (npm test -- --webgl-stub), many runs would end early with an unclear error message:

  An error was thrown in afterAll
  Unhandled promise rejection: undefined thrown

Handling the error resolves the afterAll error in some cases.

Along the way, I cleaned up some references to obsolete .initialized flags.

Issue number and link

Possibly related to #11231.

Testing plan

Run tests locally with the webgl stub (npm test -- --webgl-stub). On my machine, I can consistently trigger the afterAll error in the #d1ed5ba commit from the voxel-pick-api branch. The changes in this PR consistently prevent the error.

Author checklist

• I have submitted a Contributor License Agreement
• I have added my name to CONTRIBUTORS.md
• I have updated CHANGES.md with a short summary of my change
• I have added or updated unit tests to ensure consistent code coverage
• [ ] I have update the inline documentation, and included code examples where relevant
• I have performed a self-review of my code

[ggetz]

So just to clarify, the promise was being rejected, but the returned value is undefined?

[jjhembd]

I don't know what promise was rejected, or where undefined was thrown. ApproximateTerrainHeights was simply a guess, since it adds global state to so many test suites.

What is not clear to me is:

• Why throwing the error solves the problem
• Why the thrown error is not reported in the browser

[ggetz]

The error may be reported in the browser in the console. Have you checked?

[ggetz]

Closing this. We discussed offline that this approach is covering up a deeper issue. Thanks for taking a look @jjhembd.