Use setupPreprocessorRegistry() to setup Handlebars AST plugin

[Turbo87]

ember-cli/ember-cli#7059 changed the logic in CLI to make app available in the setupPreprocessorRegistry() hook. We should migrate to using that hook to avoid issues with parallelization in ember-cli-htmlbars-inline-precompile and ember-cli-babel.

Since this will require an update to the minimum Ember CLI versions we support this should be considered a breaking change.

/cc @rwjblue @stefanpenner

[ef4]

I'm curious if I'm understanding this correctly.

I don't think moving to the setupPreprocessorRegistry hook is necessary to support parallelization, it should be enough to pass an object with parallelBabel to registry.add. Is that right?

On the other hand, I do think there's a bug that would be fixed by moving to setupPreprocessorRegistry, which is that the inline template compiler currently doesn't seem to run the ember-test-selectors AST transform at all, because ember-cli-htmlbars-inline-precompile accesses the list of transform from its own inclued, which is racy with ember-test-selector's registration of the transform. By registering earlier in setupPreprocessorRegistry we would fix that problem.

This came up for me just now because I was using ember-test-selectors as a test case in embroider, since it conveniently has both custom AST and babel transforms that need to be handled correctly (in both regular templates and inline ones).

[Turbo87]

which is racy with ember-test-selector's registration of the transform

that is exactly the issue here 👍

when I built that code the parallelization was not available yet and setupPreprocessorRegistry() didn't have access to app. since 1) is implemented now and 2) was apparently fixed we should resolve that race condition.

[ef4]

Thanks for clarifying.