Confusing `buildStart` behavior with `createServer` API

[hi-ogawa]

Describe the bug

• Related "injectConfigValues is not a function" error when running multiple vite-node processes in parallel vitest-dev/vitest#7479

Vite-node has been using a following style of programmatic server setup https://github.com/vitest-dev/vitest/blob/94b27af595b5029b6201a7bcf2702169fe7ae6a4/packages/vite-node/src/cli.ts#L86-L99, but I'm not sure whether buildStart should be manually triggered on Vite 6 (also how perEnvironmentStartEndDuringDev should be enabled on server level or plugin level).

const server = await createServer({});
await server.pluginContainer.buildStart({})

One issue with manually calling buildStart is that:

// repro1.js
const server = await createServer({
    configFile: false,
    plugins: [
      {
        name: 'repro',
        async buildStart() {
          console.log('[repro:buildStart:in]');
          await new Promise((r) => setTimeout(r, 500));
          console.log('[repro:buildStart:out]');
        },
        transform(_code, id) {
          console.log('[repro:transform]', id);
        },
      },
    ]
});
await server.pluginContainer.buildStart({})
await server.ssrLoadModule("./src/empty.js");

which causes transform to happen before buildStart finishes:

$ node repro1.js 
[repro:buildStart:in]
[repro:transform] /xxx/src/empty.js
[repro:buildStart:out]

Probably this was the cause of vitest-dev/vitest#7479 and this can potentially break vite:client-inject since its transform relies on buildStart

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

Line 102 in 7e7b660

return defineReplacer(injectConfigValues(code))

On the other hand, one issue with not manually calling buildStart is that this breaks css import like in #19606.

// repro2.js
  const server = await createServer({
    configFile: false,
  });
  await server.ssrLoadModule("./src/import-css.js");

$ node repro2.js 
12:16:38 PM [vite] (ssr) Error when evaluating SSR module ./src/import-css.js: Cannot read properties of undefined (reading 'get')
  Plugin: vite:css-post
  File: /home/hiroshi/code/personal/reproductions/vite-19598-ssr-only-css/src/style.css
      at TransformPluginContext.transform (file:///home/hiroshi/code/personal/reproductions/vite-19598-ssr-only-css/node_modules/.pnpm/vite@6.2.1/node_modules/vite/dist/node/chunks/dep-glQox-ep.js:48442:50)
      at EnvironmentPluginContainer.transform (file:///home/hiroshi/code/personal/reproductions/vite-19598-ssr-only-css/node_modules/.pnpm/vite@6.2.1/node_modules/vite/dist/node/chunks/dep-glQox-ep.js:47637:19)
      at async loadAndTransform (file:///home/hiroshi/code/personal/reproductions/vite-19598-ssr-only-css/node_modules/.pnpm/vite@6.2.1/node_modules/vite/dist/node/chunks/dep-glQox-ep.js:41320:27)
node:internal/process/promises:394
    triggerUncaughtException(err, true /* fromPromise */);
    ^

Error [TypeError]: Cannot read properties of undefined (reading 'get')
    at TransformPluginContext.transform (file:///home/hiroshi/code/personal/reproductions/vite-19598-ssr-only-css/node_modules/.pnpm/vite@6.2.1/node_modules/vite/dist/node/chunks/dep-glQox-ep.js:48442:50)
    at EnvironmentPluginContainer.transform (file:///home/hiroshi/code/personal/reproductions/vite-19598-ssr-only-css/node_modules/.pnpm/vite@6.2.1/node_modules/vite/dist/node/chunks/dep-glQox-ep.js:47637:19)
    at async loadAndTransform (file:///home/hiroshi/code/personal/reproductions/vite-19598-ssr-only-css/node_modules/.pnpm/vite@6.2.1/node_modules/vite/dist/node/chunks/dep-glQox-ep.js:41320:27) {
  plugin: 'vite:css-post',
  id: '/home/hiroshi/code/personal/reproductions/vite-19598-ssr-only-css/src/style.css',
  pluginCode: '.test {\n  color: orange\n}\n',
  runnerError: Error: RunnerError

Reproduction

https://stackblitz.com/github/hi-ogawa/reproductions/tree/main/vite-19598-ssr-only-css?file=repro1.js

Steps to reproduce

• open stackblitz
• run node repro1.js
• run node repro2.js

System Info

System:
    OS: Linux 5.0 undefined
    CPU: (8) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 0 Bytes / 0 Bytes
    Shell: 1.0 - /bin/jsh
  Binaries:
    Node: 18.20.3 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 10.2.3 - /usr/local/bin/npm
    pnpm: 8.15.6 - /usr/local/bin/pnpm
  npmPackages:
    vite: ^6.2.0 => 6.2.1

Used Package Manager

npm

Logs

No response

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

[sapphi-red]

I'm not sure whether buildStart should be manually triggered on Vite 6 (also how perEnvironmentStartEndDuringDev should be enabled on server level or plugin level).

buildStart is called automatically for the client env for the other environments it's not called. This is to keep the compat with older versions.

vite/packages/vite/src/node/server/pluginContainer.ts

Lines 1083 to 1084 in d0aa833

	// For backward compatibility, buildStart and watchChange are called only for the client environment
	// buildStart is called per environment for a plugin with the perEnvironmentStartEndDuring dev flag

I think we need to keep this compat for now.

One issue with manually calling buildStart is that:
...
which causes transform to happen before buildStart finishes:

I think that's because we're missing await / return here.

vite/packages/vite/src/node/server/pluginContainer.ts

Lines 1086 to 1100 in d0aa833

	async buildStart(_options?: InputOptions): Promise<void> {
	;(this.environments.client as DevEnvironment).pluginContainer.buildStart(
	_options,
	)
	}
	async watchChange(
	id: string,
	change: { event: 'create' | 'update' | 'delete' },
	): Promise<void> {
	;(this.environments.client as DevEnvironment).pluginContainer.watchChange(
	id,
	change,
	)
	}

I think we can fix this way instead.

[rChaoz]

Not sure exactly why yet, but my scripts (that I run using vite-node) all started failing recently with this error:

TypeError: injectConfigValues is not a function
    at TransformPluginContext.transform
[at](plugin: 'vite:client-inject')

        return defineReplacer(injectConfigValues(code));
                              ^

so, it seems like it would be fixed by the PR above. I haven't figured out exactly what change caused this error to start appearing, but it seems to be a dependency update.

[hi-ogawa]

@rChaoz This one is supposed to be fixed (worked around) on vite-node side vitest-dev/vitest#7480. Do you have latest vite-node 3.0.8?

[rChaoz]

@hi-ogawa Thanks for the tip! Although, it's quite the opposite of what you said - it seems like the PR you linked is, in fact, what broke it for me. I am on vite-node 3.0.8 + Vite 6 and downgrading to 3.0.7 fixed the issue.

Update: I managed to get a minimal reproduction, it seems like vite-node CLI/binary is broken, I opened a separate issue for this: vitest-dev/vitest#7666