Provide cacheKey to enable cache-busting based on runtime config

[jobackman]

Hi,

So after #90 was merged ast-plugins could bust the cache based on directory changes, which is awesome and something addons like ember-cli-conditional-compile has needed for a while.

However like @rwjblue said in #90 it was made to work similarly to babel/broccoli-babel-transpiler#89, which also includes a cacheKey method which augments the cacheKeys based on runtime configurations rather than file-directory changes.

It's a feature I would like to have so this is my attempt at implementing it for HTMLBars 🙏

I've been going through various PR's like #90, babel/broccoli-babel-transpiler#89, ember-cli/babel-plugin-feature-flags#12 and what documentation I could find about it to get a grip on what it should do.

So far I have tested it with ember-cli-conditional-compile by registering the ast-plugin with cacheKey method returning its featureFlags which are based on environment setup, and it's been working well so far.

This is my first real contribution to Ember, so I might be out on deep waters, but feel free to modify or close the PR if I'm way off about this 😂

[reidab]

Any movement here? We're using ember-cli-conditional-compile and keep hitting issues around this.

[minichate]

Anything I can do to help with this?

[stefanpenner]

released as v1.3.0 🎉

[minichate]

Thanks!

[minichate]

@jobackman I'll work on applying this to https://github.com/minichate/ember-cli-conditional-compile right away