unused ssr fallback environment breaks build mode output

[dominikg]

Describe the bug

If a plugin generates any ssr config, vite automatically creates a fallback ssr environment.

vite-plugin-inspect wait until all environments are built before emitting metadata.json

vite-plugin-inspect/src/node/build.ts

Line 32 in 7959c26

if (!ranLast && remainingEnvs.size === 0) {

But if you build an spa with regular vite build, the ssr fallback environment is never built and so inspect build output isn't completed.

Reproduction

https://stackblitz.com/edit/vitejs-vite-kiuo477f?file=vite.config.js&terminal=dev

System Info

stackblitz

Used Package Manager

pnpm

Validations

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• The provided reproduction is a minimal reproducible of the bug.

Contributions

• I am willing to submit a PR to fix this issue
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[dominikg]

can be worked around with a plugin that removes any ssr config created by other plugins in the last slot

{
	name: 'vite-plugin-no-ssr-fallback-env',
	enforce: 'post',
	config:{
		order: 'post',
		handler(c){
			delete c.ssr;
		}
	}
}

[antfu]

Do you have any suggestions/ideas on how to fix this?

[dominikg]

There was a brief discussion on vite discord about this.

@sapphi-red suggested plugins should prefer configureEnvironment hook to set up ssr specific config (eg by checking environment.config.consumer). This can resolve the problem over time (esp. when vite 8 or 9 might stop to create a fallback ssr env).

Not sure whats the best way to improve this in the interim. Instead of counting environments, maybe count buildStart calls?

edit: buildStart could come with its own issues in case someone used it with build --watch. Detecting first build done and then rebuilds is a separate discussion though.