How to generate sourcemaps?

[frederikhors]

Hi @kaisermann, amazing project, thanks for your work!

In my Sapper project I have in rollup.config.js:

...
const preprocessOptions = {
  scss: { includePaths: ['src', 'node_modules'] },
  postcss: {
    plugins: [
      autoprefixer,
      !dev && cssnano
    ].filter(plugin => plugin)
  }
}
const preprocess = autoPreprocess(preprocessOptions)
const sourcemap = process.env.GENERATE_SOURCEMAP || config.client.output().sourcemap

export default {
  client: {
    input: config.client.input(),
    output: { ...config.client.output(), sourcemap },
    plugins: [
      ...
      svelte({
        dev,
        hydratable: true,
        emitCss: true,
        preprocess
      }),
...

This create a good css in __SAPPER__/build/main.[hash].css but I need sourcemaps.

Is there a way?

I think I can use the below but I think I'm wrong.

...
svelte({
  dev,
  hydratable: true,
  emitCss: true,
  css: css => css.write('dist/bundle.css', sourcemap), // <-- wrong directory and content
  preprocess
}),
...

[kaisermann]

Het @frederikhors 👋 Currently, the svelte compiler doesn't handle any sourcemap generated by preprocessors. There's a PR by @halfnelson that will add support for sourcemap sometime in the future. Whenever it lands, I guarantee will be passing sourcemaps down the pipeline 😁.

[frederikhors]

Please do not close this, as a remainder.

[kaisermann]

@frederikhors Sourcemaps are already generated if you have the appropriate option configured for your preprocessor, and are returned to the compiler. Don't worry, I'll make sure to create some tests to guarantee they are being returned. However, for now, there's nothing more we can do from this side. Waiting for: sveltejs/svelte#5015.

[MingweiSamuel]

sveltejs/svelte#5015 -> sveltejs/svelte#5428 -> sveltejs/svelte#5584
for reference