A method of adding an import based on dependency graph

[benmccann]

Feature Use Case

Sapper has a CSS-handling plugin, which has recently been significantly cleaned up and is about ready to graduate into a separate Rollup plugin for wider community use:

https://github.com/sveltejs/sapper/blob/ead10eebb7416971a390a0190f1df7c1f3327791/src/core/create_compilers/RollupCompiler.ts#L156

It finds CSS that a dynamically imported chunk tree includes and then rewrites the dynamic imports with an extra bit of code. That code makes it so that in parallel to the original dynamic import we also write link tags pointing to the CSS.

So as not to duplicate code across chunks, this plugin emits a new inject_styles chunk. It then adds an import to that chunk where it's used. The problem here is that this import does not show up in the chunk.imports for the plugins that follow it.

Feature Proposal

Things I've tried:

• I've tried doing chunk.imports.push(newImport) when adding the import in generateBundle. This does not persist for the next plugin
• I've tried rewriting the code in transform. This does not work because I don't have access to the dependency graph. When I call this.getModuleInfo it returns empty arrays for the importedIds and dynamicallyImportedIds
• I've tried rewriting the code in renderChunk. However, I don't know the file name to add. If I simply do import __inject_styles from 'inject_styles.js' then that doesn't get properly rewritten to include the hash in the filename.

It would be nice if at least one of these worked or there was another solution to this problem

Related Requests

#3519

[codepunkt]

I've been running into an issue that is kinda similar. Did you have any success?

[lukastaegert]

I've tried rewriting the code in transform. This does not work because I don't have access to the dependency graph. When I call this.getModuleInfo it returns empty arrays for the importedIds and dynamicallyImportedIds

Sorry for not getting back to you when this issue was created. A lot has happened since then, especially the introduction of the this.load context function. I have recently put some work into streamlining the process of scanning dependency graphs inside build time hooks, maybe #4358 will allow you to solve the issue?

[benmccann]

Sapper has been replaced by SvelteKit, which is built on top of Vite, so I no longer have a direct need for this. I see a few folks from the Vite team copied on #4358. As far as I'm concerned, I'm happy with any solution they're happy with, so feel free to link this issue to that PR so that it will be closed by it

[lukastaegert]

#4543 now allows you (even encourages you) to update the import/export information when updating a chunk

[rollup-bot]

This issue has been resolved via #4543 as part of rollup@3.0.0-7. Note that this is a pre-release, so to test it, you need to install Rollup via npm install rollup@3.0.0-7 or npm install rollup@beta. It will likely become part of a regular release later.

[rollup-bot]

This issue has been resolved via #4543 as part of rollup@3.0.0-8. Note that this is a pre-release, so to test it, you need to install Rollup via npm install rollup@3.0.0-8 or npm install rollup@beta. It will likely become part of a regular release later.

[rollup-bot]

This issue has been resolved via #4543 as part of rollup@3.0.0. You can test it via npm install rollup.