Set sourceRoot in babel-register transform to fix paths in stacks

[danez]

This is the followup of #3523 which was reverted.

This change fixes the stacktraces by setting sourceRoot in the options. This does not touch the sources or file property in the map, but adds a property called sourceRoot. By spec the sourceRoot is prepended to sources and file.

Resolving Sources
If the sources are not absolute URLs after prepending of the “sourceRoot”, the sources are resolved relative to the SourceMap (like resolving script src in a html document).

Printing absolute paths is also more in line with node itself, which prints absolute paths in its traces.

I tested the previously failing project with this change and it worked.

i also thought about tests, but the main blocker right now is that there is no way to unregister babel-register which messes then with other tests. As soon as we merge #3139 it might get possible to write tests and after the test to properly unhook.

[codecov-io]

Current coverage is 87.53% (diff: 100%)

No coverage report found for master at 35a258f.

Powered by Codecov. Last update 35a258f...54115fb

[hzoo]

We can make a new pr for #3139 with the changes

[just-boris]

Hello! As far as pirates will not come soon, it there a chance to merge this?

[just-boris]

Hello again! Any updates about this?

I figured out that source map issue makes my tests unusable.

I have typical React-components folder with the following structure:

app/components/
├── button
│   ├── index.js
│   └── styles.scss
└── table
    ├── index.js
    └── styles.scss

I have an index.js file for each components, but then I run tests with mocha and babel-register hook and I am getting useless error messages.

 TypeError: Cannot read property 'label' of undefined
      at mapStateToProps (index.js:45:17)

I see only filename, but this is index.js which gives me zero information about actual place in source code.

[just-boris]

Also, I tested this fix, it gives full paths to stacktrace, and doesn't break coverage report.