Fix sourceMappingURL for bundles with multiple entry points [CSS]

[rynpsc]

↪️ Pull Request

Fixes incorrect sourcemap URL's when you have multiple entry points.

Related issue #2851

💻 Examples

Given the followong CLI command

parcel build src/a/style.css src/b/style.css

The following files are produced

dist/a/style.css /*# sourceMappingURL=/style.css.map */
dist/b/style.css /*# sourceMappingURL=/style.css.map */

The sourcemap URLs are incorrect they should be /a/style.css.map and /b/style.css.map.

With the fix in place we instead get:

dist/a/style.css /*# sourceMappingURL=/a/style.css.map */
dist/b/style.css /*# sourceMappingURL=/b/style.css.map */

The same issue was previously fixed with JavaScript sourcemaps #2645

✔️ PR Todo

• Added/updated unit tests for this change
• Filled out test instructions (In case there aren't any unit tests)
• Included links to related issues/PRs

[rynpsc]

Have updated desciptions and added tests. Currently failing due to #2842.

[mischnic]

Now consistent with the logic in JSPackager.js 👍

[rynpsc]

@mischnic Noticed the check for the sourcemap comment was using JS syntax rather than CSS.

[mischnic]

Noticed the check for the sourcemap comment was using JS syntax rather than CSS.

We really need to get CI working again.

Very picky comment: could you rename the vars in that test? (from jsOutput)

[sammckay10]

Has this been merged?!?

[mmcc]

I'm running into this exact issue and it appears this was approved, but closed instead of merged (unless I'm mistaken). Was that an accident?