fix(vitest): remove excessive listeners when running without isolation, don't reset the state (#5132)

Author: sheremet-va

packages/vitest/src/runtime/execute.ts

@@ -42,14 +42,11 @@ export interface ContextExecutorOptions {
 
 const bareVitestRegexp = /^@?vitest(\/|$)/
 
-export async function startVitestExecutor(options: ContextExecutorOptions) {
-  // @ts-expect-error injected untyped global
-  const state = (): WorkerGlobalState => globalThis.__vitest_worker__ || options.state
-  const rpc = () => state().rpc
+const dispose: (() => void)[] = []
 
-  process.exit = (code = process.exitCode || 0): never => {
-    throw new Error(`process.exit unexpectedly called with "${code}"`)
-  }
+function listenForErrors(state: () => WorkerGlobalState) {
+  dispose.forEach(fn => fn())
+  dispose.length = 0
 
   function catchError(err: unknown, type: string) {
     const worker = state()
@@ -60,13 +57,31 @@ export async function startVitestExecutor(options: ContextExecutorOptions) {
         error.VITEST_TEST_PATH = relative(state().config.root, worker.filepath)
       error.VITEST_AFTER_ENV_TEARDOWN = worker.environmentTeardownRun
     }
-    rpc().onUnhandledError(error, type)
+    state().rpc.onUnhandledError(error, type)
   }
 
-  process.setMaxListeners(25)
+  const uncaughtException = (e: Error) => catchError(e, 'Uncaught Exception')
+  const unhandledRejection = (e: Error) => catchError(e, 'Unhandled Rejection')
+
+  process.on('uncaughtException', uncaughtException)
+  process.on('unhandledRejection', unhandledRejection)
+
+  dispose.push(() => {
+    process.off('uncaughtException', uncaughtException)
+    process.off('unhandledRejection', unhandledRejection)
+  })
+}
+
+export async function startVitestExecutor(options: ContextExecutorOptions) {
+  // @ts-expect-error injected untyped global
+  const state = (): WorkerGlobalState => globalThis.__vitest_worker__ || options.state
+  const rpc = () => state().rpc
+
+  process.exit = (code = process.exitCode || 0): never => {
+    throw new Error(`process.exit unexpectedly called with "${code}"`)
+  }
 
-  process.on('uncaughtException', e => catchError(e, 'Uncaught Exception'))
-  process.on('unhandledRejection', e => catchError(e, 'Unhandled Rejection'))
+  listenForErrors(state)
 
   const getTransformMode = () => {
     return state().environment.transformMode ?? 'ssr'

packages/vitest/src/runtime/rpc.ts

@@ -73,6 +73,10 @@ export function createRuntimeRpc(options: Pick<BirpcOptions<RuntimeRPC>, 'on' |
         if (functionName === 'fetch' || functionName === 'transform' || functionName === 'resolveId')
           message += ` with "${JSON.stringify(args)}"`
 
+        // JSON.stringify cannot serialize Error instances
+        if (functionName === 'onUnhandledError')
+          message += ` with "${args[0]?.message || args[0]}"`
+
         throw new Error(message)
       },
       ...options,

packages/vitest/src/runtime/worker.ts

@@ -3,7 +3,6 @@ import { workerId as poolId } from 'tinypool'
 import { ModuleCacheMap } from 'vite-node/client'
 import type { ContextRPC } from '../types/rpc'
 import { loadEnvironment } from '../integrations/env/loader'
-import type { WorkerGlobalState } from '../types/worker'
 import { isChildProcess, setProcessTitle } from '../utils/base'
 import { setupInspect } from './inspector'
 import { createRuntimeRpc, rpcDone } from './rpc'
@@ -21,8 +20,6 @@ export async function run(ctx: ContextRPC) {
   process.env.VITEST_WORKER_ID = String(ctx.workerId)
   process.env.VITEST_POOL_ID = String(poolId)
 
-  let state: WorkerGlobalState | null = null
-
   try {
     // worker is a filepath or URL to a file that exposes a default export with "getRpcOptions" and "runTests" methods
     if (ctx.worker[0] === '.')
@@ -46,7 +43,7 @@ export async function run(ctx: ContextRPC) {
     if (ctx.environment.transformMode)
       environment.transformMode = ctx.environment.transformMode
 
-    state = {
+    const state = {
       ctx,
       // here we create a new one, workers can reassign this if they need to keep it non-isolated
       moduleCache: new ModuleCacheMap(),
@@ -70,9 +67,5 @@ export async function run(ctx: ContextRPC) {
   finally {
     await rpcDone().catch(() => {})
     inspectorCleanup()
-    if (state) {
-      state.environment = null as any
-      state = null
-    }
   }
 }