gulp-sourcemaps: sourceRoot doesn't work for files in sub folders

I agree that the sourceRoot option does not work as expected when assigning a string value and source files are located in sub directories.

Here’s a workaround using the path util:

const path = require('path');
// ...
sourceRoot: (file) => {
    return path.join(path.relative(path.join(outputDir, path.dirname(file.relative)), '.'), sourceDir);
}

Hi I’ve got same issue Thanks @ckiely91. Your solution was very helpful. Here is my full task for “Node.js targeted” TS. Hope it would be useful…

gulp.task('build', () => {
  const project = ts.createProject('tsconfig.json');
  return gulp.src('./app/**/*.ts')
    .pipe(sourcemaps.init())
    .pipe(ts(project))
    .js
    .pipe(sourcemaps.write('./', {
      includeContent: false,
      sourceRoot: file => `${'../'.repeat(file.relative.split(/^win/.test(process.platform) ? '\\' : '/').length)}app`
    }))
    .pipe(gulp.dest('./dist'));
});

I found following code in sources of plugin

    if (typeof options.sourceRoot === 'function') {
      sourceMap.sourceRoot = options.sourceRoot(file);
    } else {
      sourceMap.sourceRoot = options.sourceRoot;
    }

Looks like sourceMap passed to output as is without, resolution of extra ../

Well, I had lots of trouble, trying to find the right combination to make it work. In the end I found a simple expression that worked for any combination of subdirectories, depth or relative location between the source and build directories:

const writeSourceMapsOptions = {
  sourceRoot: (file) => {
    return path.posix.relative(path.posix.dirname(file.relative), "");
  },
};

and then just pass it to .pipe(gulpSourceMaps.write(writeSourceMapsOptions)).

This works for both Istambul reports and the Node debugger.

For whatever reason updating the sourceRoot as above didn’t work for me so I updated the mapSources directly. Thanks to everyone for leading me to this!

mapSources: function(sourcePath, file) { let relativeLocation = path.join(path.relative(path.join(outputDir, path.dirname(file.relative)), ‘.’), ‘src/’); let relativeLocationToFile = path.join(relativeLocation, sourcePath); return relativeLocationToFile; }}))

@zhakhalov, found that you can actually just use path.sep instead of /^win/.test(process.platform) ? '\\' : '/' to make it platform independent.