Add file extension to preprocessor

[mfeckie]

After learning way more about the internals of broccoli and ember-cli than I'd expected to today ...

Using broccoli-stew to print out the inputNode in toTree, I noticed that it was being passed

include: [/js$/]

This seems to only be the case for the addon directory, which is why I think it wasn't breaking in 'normal' app usage. The toTree hook gets called three times (addon, app and tests). The tree received when invoked by app is quite different to the one from addon.

After digging around I noticed in here https://ember-cli.com/api/classes/Addon.html#method_setupPreprocessorRegistry that the file extension is used to determine the tree that the preProcessor receives.

Adding the extension to the TypeScriptPreprocessor changes it to this

include: [/js$/, /ts$/]

Which results in the typescript files being correctly passed to the tsc compiler.

[chriskrycho]

Ahhhh, very nice catch there—thanks @mfeckie and @twokul!