Generate stand-alone source maps

[code-later]

Dear faucet-pipeline team,

while using faucet-pipeline works like a charm and really goes out of your way, I recently stumbled across a feature I would like to see added: Currently there is an option to generate inline source maps. This works great for development but if you use an error tracking service (i.e. Rollbar) the source maps must be provided separately: https://docs.rollbar.com/docs/source-maps.

Thus it would be great to have an option to generate the source maps into dedicated file(s). Of course they must be uploaded as well, but this should not be of any concern to faucet-pipeline I guess.

[FND]

Hey Dirk, thanks for providing some context here.

I assume your concern is primarily about JavaScript source maps? Since I don't use (am philosophically opposed to 👴 ) source maps myself, I never fully grokked how our implementation actually works in detail. So I'm not really sure what needs to be done to support stand-alone source maps, but I can (grudgingly 😉 ) try to provide some guidance for anyone interested in implementing this:

Support for source maps was introduced in 61f8576, and it looks like Rollup supports what you want. So I'm guessing it should be possible to extend our implementation by massaging faucet's sourcemaps option - perhaps similar to the way compacting works: cce6245 (--sourcemaps to activate, optional sourcemaps configuration in bundle configuration for customization). HTH.

[code-later]

Thanks @FND for the feedback and even more the guidance. I'll give it a try and have a look on how to add this to faucet-pipeline.

[FND]

FWIW, having encountered externalized source maps elsewhere recently, I've realized that it might be simpler than I'd expected: The actual source map's JSON data remains identical AFAICT, the respective file is referenced as //# sourceMappingURL=bundle.js.map from within the bundle - so we'd just need to write the same data to a separate file (${bundle.filepath}.map) and replace the Base64-encoded data URI with this reference.

Having said that, this might require a little bit of re-architecting:

faucet-pipeline-js/lib/bundle/bundler.js

Line 23 in 53f4f87

code: map ? `${code}\n${SMPREFIX}${map.toUrl()}\n` : code,

The generateBundle function there (intentionally) doesn't have access to assetManager.writeFile, so we'd probably wanna extend the return value to { code, map, … } to eventually (via BasicBundle and Bundle - yes, this is a little convoluted, because reasons) write a source-map file alongside the actual bundle:

faucet-pipeline-js/lib/index.js

Line 43 in 53f4f87

return ({ code, error }) => {