babelOptions ignored in esm compiler

[malaupa]

babelOptions defined in jspm.conf.js or by direct calling SystemJS.conf() or System.conf() are not passed to the babel transpiler in https://github.com/systemjs/builder/blob/master/compilers/esm.js#L59. Isn't it needed at this place? This causes warnings of the babel transpiler for large files, because compact mode can't be enabled : https://github.com/babel/babel/blob/master/packages/babel-generator/src/index.js#L81.

[guybedford]

This is a different transpilation which only converts ES modules into System.register, separate to the other Babel transforms.

An option to pass compact here could be worth providing though.

[malaupa]

Why is Babel called twice? Babel could do all transpilation in one step for a file or I am wrong!? Please, could you shortly explain in which steps the builder transpiles the source code files?

Why is it hard to achieve to set the compact option for the transform operation? The options object is present on the builder instance or isn't it?

Thanks for answering in advance

[guybedford]

Are you trying to turn compact on or off?

[malaupa]

Yes, by setting in jspm.conf.js and by .babelrc, but the call at line esm.js#59 doesn't pass the compact option. I have debugged it by creating a gulp task and call the Builder directly.

[guybedford]

Specifically I was wondering what value you wanted for the compact option, to understand the use case better.

[malaupa]

Sorry, I want to disable the warning by using compact=true, which is logged for compact="auto" (default value) in line index.js#L81 for large files.

[guybedford]

I'd be open to setting a hard default of compact: false if you think that could work.

[malaupa]

Yes, this should work.

For understanding systemjs and systemjs/builder in more detail, do you have a short description, documentation for the internal architecture? It would be helpful for using systemjs in the correct intended way. Especially for Babel. I saw you are working on docs, could it be part of it?

Thanks

[laurentgoudet]

I'd be open to setting a hard default of compact: false if you think that could work.

I'd love to have a compact: false hard default as well. Not only to remove the annoying [BABEL] Note: The code generator has deoptimised the styling of "..." as it exceeds the max of "100KB". warnings, but also because it makes debugging such modules such harder due to the deoptimised styling.

[guybedford]

Sure, added in 8a73596.

[guybedford]

Released in 0.15.33.