Incorporate cache keys.

[rwjblue]

Provide baseDir and pass through second argument as cacheKey.

This is backwards compat to 0.0.5...

[Turbo87]

@rwjblue could you crosslink why you're doing this?

[rwjblue]

The upstream usage of baseDir and cacheKey functions is being added here: babel/broccoli-babel-transpiler#89.

Right now, the following scenario will leave you with a cached JS file that is not properly invalidated:

ember new foo
cd foo
ember g component foo
ember test
bower install --save ember#alpha
ember test

The last ember test will fail because the template compilation output is different between 1.10 - 2.8 and the alpha, and since this plugin rewrites the transpiled output to include the result of Ember.Handlebars.compile but the template compiler itself isn't part of the broccoli-babel-transpiler's cache keys we end up with embedded templates that will only be recomputed if you change the file (to invalidate the cache another way).

babel/broccoli-babel-transpiler#89 is aiming to solve this, and will warn/deprecate/etc any instances where the baseDir is not present.

[Turbo87]

okay LGTM, could you maybe add a few short code comments and/or a sentence about it to the README?

@stefanpenner @pangratz r+?

[rwjblue]

@Turbo87 - Update README and added a couple inline comments explaining why this is being done.

[Turbo87]

I have to admit I'm not entirely happy with the approach because it is very uncommon to pass functions to Babel plugins and even more so to Babel 6 plugins where they are usually referenced in a .babelrc JSON file that has no support for functions. I understand though that we are already passing in the main precompile function and that is why I have mixed feelings about it...

does cacheKey have to be a function?

should we actually bundle/depend on the handlebars precompiler in this plugin instead of passing it in like we currently do?

[stefanpenner]

@Turbo87 would love your 👀 on this, and ideas to improve it.

[rwjblue]

even more so to Babel 6 plugins where they are usually referenced in a .babelrc JSON file that has no support for functions

In the upstream changes this case is handled properly in the default scenario you describe. When the config includes an array (where options are the second item in the array), those options are used for the cache key by default. If a function is found in that options hash, it is expected to include its own cacheKey/baseDir.

does cacheKey have to be a function?

options.cacheKey does not need to be a function, I only made it a function to be the same as what the plugin itself is expected to provide.

should we actually bundle/depend on the handlebars precompiler in this plugin instead of passing it in like we currently do?

We cannot bundle here, as it is dependent on the Ember version in use by the app itself (and changes per build).

I understand though that we are already passing in the main precompile function and that is why I have mixed feelings about it.

I'm not sure what else we can do, but we must do something. I'm definitely open to ideas...

[rwjblue]

does cacheKey have to be a function?

Updated to make options.cacheKey a primitive value.

[rwjblue]

Chatted with @Turbo87 and he is not super opposed to shipping this for now and coming back to fix things when Ember itself can ship as an NPM package (and we can avoid passing this function around like this).