When uglify-js fails to parse, it should throw a more specific Error

[michaelfranzl]

builder/lib/output.js

Line 80 in 52ad54c

throw new Error(e);

When uglify-js fails to parse (i.e. when some ES6 module was accidently not configured to be transpiled to ES5), it should not simply re-throw the uglify-js error, since it only contains filename: '0'. The error should contain the currently processed fileName. Ideally, the offending line should be output too.

[guybedford]

Thanks for posting, and apologies for the delay.

I'd be happy to review a PR for this.