Source maps and external libraries, wrong sources.

[artursoler]

When using source maps with external libraries (it has happened to me both with scalatags and with scalajs-react), it seems like the file paths of the computer where the library build was done are being leaked.

Example of paths I'm finding when browsing the generated map file:

1: "file:///home/golly/projects/scalajs-react/core/src/main/scala/japgolly/scalajs/react/vdom/ReactTags.scala"
2: "file:///home/golly/projects/scalajs-react/core/src/main/scala/japgolly/scalajs/react/vdom/ReactVDom.scala"
3: "file:///Users/haoyi/Dropbox%20(Personal)/Workspace/scalatags/js/../shared/main/scala/scalatags/generic/Util.scala"
4: "file:///Users/haoyi/Dropbox%20(Personal)/Workspace/scalatags/js/../shared/main/scala/scalatags/generic/Attrs.scala"
5: "file:///Users/haoyi/Dropbox%20(Personal)/Workspace/scalatags/js/../shared/main/scala/scalatags/generic/Styles.scala"
6: "file:///Users/haoyi/Dropbox%20(Personal)/Workspace/scalatags/js/../shared/main/scala/scalatags/generic/Core.scala" ```

[sjrd]

That's the given libraries' fault ;-) They should use the -P:scalajs:mapSourceURI option in scalacOptions to tell the compiler a public URI where sources can be found (typically a GitHub raw URL).

-P:scalajs:mapSourceURI:FROM_URI[->TO_URI]
change the location the source URIs in the emitted IR point to

• strips away the prefix FROM_URI (if it matches)
• optionally prefixes the TO_URI, where stripping has been performed
• any number of occurences are allowed. Processing is done on a first match basis.

[artursoler]

Thanks for the fast response, Sébastien.

I'll close this issue and open one in each of the libraries.

[vendethiel]

Maybe this should be mentioned in the docs (not only the API)? I spent some time looking for that exact options

[sjrd]

@Nami-Doc Sure! Where do you think it would be best to put it?

[vendethiel]

I first looked in the sbt plugin doc, so I'd say there. I'm not sure with what it'd go, though. Maybe there are other options you want to cover

[sjrd]

Maybe an additional section in sbt plugin doc for "Publishing libraries"?

[vendethiel]

I'm not sure this should be cornered to library publishing? I'm hitting this issue on a local project, myself

[sjrd]

Ah? But for a local project, the source maps pointing to your local files should work, don't they?

[vendethiel]

The .js.map file contains file:///Users/... for me. Not sure if I'm doing something wrong?

EDIT: it seems scala-js-dom has file:///Users/tschlatt/Documents/scala-js-dom/
EDIT: also, if you don't provide a mapping, I could see TO_URI being / by default (root). not sure
EDIT: Currently using that, and it works great:

s"-P:scalajs:mapSourceURI:file://${baseDirectory.value}->/"