Plugin legacy skip emit assets

[marco-prontera]

Describe the bug

Hi guys, the latest version of the legacy plugin, no longer issues assets. This does not allow some plugins I use to apply logic even to the generated legacy bundle.

The line is this:
opts.__vite_skip_asset_emit__ = true

I think it is more appropriate to give the possibility to decide by means of a parameter. Obviously, you can set it to true by default in order to skip.

That would be great, thank you in advance, and thank you for your work ❤️.

Reproduction

All

System Info

All

Used Package Manager

npm

Logs

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[bluwy]

Related: #6584. That PR fixes some issues, which seems to conflict with this feature request. Can you further elaborate your use case and provide some examples of it?

[marco-prontera]

@bluwy
Essentially the use case is the following: When I use my plugin for Vite to inject the CSS generated by the JS, I need also to inject the same CSS into the legacy bundle generated. But, the legacy code generation happens before the standard flow of Vite, so I don't have the possibility to get the CSS generated and put it inside the legacy bundle.

Now I leave you the link to the plugin here. You can try it and see that for the legacy bundle the CSS is empty. This can be fixed by generating the legacy bundle after the standard flow or giving the possibility through a param to choose if I need the CSS in the chunking phase during the legacy generation.

Thanks
https://github.com/Marco-Prontera/vite-plugin-css-injected-by-js

[marco-prontera]

@bluwy I created a PR to cover those requirements. If you can see it, is very simple and it'a implementation is covered by a documentation that tells the purpose.

Thanks in advance

[bluwy]

Thanks for providing your usecase. I tested this on stackblitz and it seems to be working fine in a different way. It looks like Vite already inlines css in legacy with this code

vite/packages/vite/src/node/plugins/css.ts

Lines 459 to 468 in 1d468c8

	// legacy build, inline css
	chunkCSS = await processChunkCSS(chunkCSS, {
	inlined: true,
	minify: true
	})
	const style = `__vite_style__`
	const injectCode =
	`var ${style} = document.createElement('style');` +
	`${style}.innerHTML = ${JSON.stringify(chunkCSS)};` +
	`document.head.appendChild(${style});`

so maybe it's not needed for the plugin to handle it?

[marco-prontera]

Thanks, I knew about the configuration through Vite, but in this case, I cannot choose the details.
I would also need to inject code that comes from "dynamic" sources, I have a custom version that allows me to optimize a product through the build phase, taking some style and putting it directly in the build (even legacy build).
But for now, I have to use a custom (local) version of the legacy plugin with the modification proposed in PR.