No source map support

[claydiffrient]

When using this as a post loader in my webpack config:

webpackConfig.module.postLoaders = [
  {
    test: /\.jsx$/,
    exclude: /(test|node_modules|bower_components)\//,
    loader: 'istanbul-instrumenter'
  }
];

It ends up destroying source maps: devtool: 'source-map',

For now my work around is to do

let istanbulInstrumenter =  {
    test: /\.jsx$/,
    exclude: /(test|node_modules|bower_components)\//,
    loader: 'istanbul-instrumenter'
  };
webpackConfig.module.postLoaders = IS_CI_ENV ? [istanbulInstrumenter] : []

Which works for when I want it to do coverage from my CI environment, but makes it so it's slightly more difficult to get coverage locally.

[deepsweet]

afaik there is no source maps support gotwarlost/istanbul#212 + karma-runner/karma-coverage#109, so there is nothing to return from the loader.

btw, are you sure that you really need source maps in case of code coverage?

[claydiffrient]

Fair point.

Well, I use the same webpack config for development and testing. Maybe I should split that out instead. The source maps I need for development, but the coverage I want as part of testing. So having to comment out the instrumenter or provide a ENV variable is a bit cumbersome.

But yeah, I don't need source maps when doing coverage, feel free to close this issue. The true thing for me to do is have my test environment load a different webpack config than my local environment.

[deepsweet]

usually I have 3 webpack configs inherited from "common" one: build, dev and test. so maybe it's a good moment to start splitting :)

[alexgorbatchev]

I think the sourcemap is now used to remap covered JS code back to original source it was transpiled from. With babel, typescript & angular 2 this is becoming a must have feature. See

• https://github.com/SitePen/remap-istanbul
• and a very long thread in istanbul repo on this subject Better integration with other pre-processors gotwarlost/istanbul#212

[asci]

+1 - new babel does not support correct auxiliaryCommentBefore - but supports source maps, as well as istambul 1.0.0-alpha.2