Add support for file source maps

[aaronjensen]

Addresses #51

[aaronjensen]

This currently only applies to when optionsCount <= 1 (I'm not really sure what that is...) but I can adapt it to the other if this looks good.

[aaronjensen]

Ah... it looks like it's for supporting multiple webpack configs. It concatenates all of the output files... I'm not sure how that could work with sourcemaps. It probably didn't w/ the old method, did it?

We'd have to fetch all of the source maps and adjust the line numbers to deal w/ the concat, right?

[aaronjensen]

For anyone coming here, I published https://www.npmjs.com/package/karma-webpack-with-fast-source-maps for now until this is updated

[dignifiedquire]

This looks really nice to me. Thanks @aaronjensen
@sokra could you take a look when you have a moment please, and let me know if I'm okay to merge this.

[sokra]

It would be great if this also work for the optionsCount > 1 case. Shouldn't be to complex to adjust it.

[aaronjensen]

@sokra @dignifiedquire Thanks.

I did not really know how to test with optionsCount > 1. Am I right that we would have to concat all of the source maps and adjust line numbers?

Does anyone know why cheap-module-inline-source-map does not work w/ the current version?

[sokra]

Am I right that we would have to concat all of the source maps and adjust line numbers?

Yes, but there are tools out there which do this for you. You can use the source-map lib, which is the lib devtool: "source-map" uses, or you can use the source-list-map lib, which is the lib devtool: "cheap-source-map" and variants uses.

source-map: 
SourceNode.fromStringWithSourceMap
  -> new SourceNode(..., [a, b, c])
  -> SourceNode.toStringWithSourceMap.

source-list-map:
fromStringWithSourceMap(...)
  -> SourceListMap.add
  -> SourceListMap.toStringWithSourceMap

[aaronjensen]

fyi @sokra I don't know how to progress on this because of #77

I also don't know what multiple configurations is used for. Thanks!

[joshwiens]

@aaronjensen - What do you want to do here? We can resurrect this PR after we merge in all the code validations / es6 support or get the team to brainstorm a solution. Sourcemaps / Performance are on the hotlist once we have proper testing in place.

[aaronjensen]

@d3viant0ne Yes, that'd be great. I didn't feel comfortable with this change given the lack of coverage and my lack of understanding of multiple webpack configs, but it'd be great to get something like this merged in so my fork can go away.

[jsf-clabot]

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[joshwiens]

That was unintentionally closed when I fixed the master branch. @aaronjensen next time you have 3/4 minutes free, ping me in slack.

[aaronjensen]

@d3viant0ne i pinged you on gitter, not sure if that's what you meant or if there's a webpack slack I don't know about

[mgol]

@d3viant0ne Why did you close it? I don't see a fix on master.

[joshwiens]

Fixing the master branch. This feature hasn't gone anywhere nor has the plan changed, @aaronjensen is a part of the webpack organization. This effort will be taken up again at the appropriate time.

[mgol]

OK, thanks for the update.