feat: restart vitest on config change

packages/vitest/src/constants.ts

@@ -7,6 +7,8 @@ export const distDir = resolve(url.fileURLToPath(import.meta.url), '../../dist')
 // if changed, update also jsdocs and docs
 export const defaultPort = 51204
 
+export const EXIT_CODE_RESTART = 43
+
 export const API_PATH = '/__vitest_api__'
 
 export const configFiles = [

packages/vitest/src/node/cli-api.ts

@@ -1,5 +1,6 @@
 import { resolve } from 'pathe'
 import type { UserConfig as ViteUserConfig } from 'vite'
+import { EXIT_CODE_RESTART } from '../constants'
 import { CoverageProviderMap } from '../integrations/coverage'
 import { envPackageNames } from '../integrations/env'
 import type { UserConfig } from '../types'
@@ -60,9 +61,13 @@ export async function startVitest(cliFilters: string[], options: CliOptions, vit
   if (process.stdin.isTTY && ctx.config.watch)
     registerConsoleShortcuts(ctx)
 
-  ctx.onServerRestarted(() => {
-    // TODO: re-consider how to re-run the tests the server smartly
-    ctx.start(cliFilters)
+  ctx.onServerRestart((reason) => {
+    ctx.report('onServerRestart', reason)
+
+    if (process.env.VITEST_CLI_WRAPPER)
+      process.exit(EXIT_CODE_RESTART)
+    else
+      ctx.start(cliFilters)
   })
 
   try {

packages/vitest/src/node/cli-wrapper.ts

@@ -5,17 +5,23 @@
 import { fileURLToPath } from 'url'
 import c from 'picocolors'
 import { execa } from 'execa'
+import { EXIT_CODE_RESTART } from '../constants'
 
 const ENTRY = new URL('./cli.mjs', import.meta.url)
-const NODE_ARGS = ['--inspect', '--inspect-brk', '--trace-deprecation']
+
+/** Arguments passed to Node before the script */
+const NODE_ARGS = [
+  '--inspect',
+  '--inspect-brk',
+  '--trace-deprecation',
+]
 
 interface ErrorDef {
   trigger: string
   url: string
 }
 
-// Node errors seen in Vitest (vitejs/vite#9492)
-const ERRORS: ErrorDef[] = [
+const SegfaultErrors: ErrorDef[] = [
   {
     trigger: 'Check failed: result.second.',
     url: 'https://github.com/nodejs/node/issues/43617',
@@ -30,9 +36,10 @@ const ERRORS: ErrorDef[] = [
   },
 ]
 
+main()
+
 async function main() {
   // default exit code = 100, as in retries were exhausted
-  const exitCode = 100
   let retries = 0
   const args = process.argv.slice(2)
 
@@ -52,24 +59,6 @@ async function main() {
     }
   }
 
-  retries = Math.max(1, retries || 1)
-
-  for (let i = 1; i <= retries; i++) {
-    if (i !== 1)
-      console.log(`${c.inverse(c.bold(c.magenta(' Retrying ')))} vitest ${args.join(' ')} ${c.gray(`(${i} of ${retries})`)}`)
-    await start(args)
-    if (i === 1 && retries === 1) {
-      console.log(c.yellow(`It seems to be an upstream bug of Node.js. To improve the test stability,
-you could pass ${c.bold(c.green('--segfault-retry=3'))} or set env ${c.bold(c.green('VITEST_SEGFAULT_RETRY=3'))} to
-have Vitest auto retries on flaky segfaults.\n`))
-    }
-  }
-  process.exit(exitCode)
-}
-
-main()
-
-async function start(args: string[]) {
   const nodeArgs: string[] = []
   const vitestArgs: string[] = []
 
@@ -87,23 +76,62 @@ async function start(args: string[]) {
       vitestArgs.push(args[i])
   }
 
-  const child = execa('node', [...nodeArgs, fileURLToPath(ENTRY), ...vitestArgs], {
-    reject: false,
-    stderr: 'pipe',
-    stdout: 'inherit',
-    stdin: 'inherit',
-  })
+  retries = Math.max(1, retries || 1)
+
+  for (let i = 1; i <= retries; i++) {
+    const result = await start(nodeArgs, vitestArgs)
+
+    if (result === 'restart') {
+      i -= 1
+      continue
+    }
+
+    if (i === 1 && retries === 1) {
+      console.log(c.yellow(`It seems to be an upstream bug of Node.js. To improve the test stability,
+you could pass ${c.bold(c.green('--segfault-retry=3'))} or set env ${c.bold(c.green('VITEST_SEGFAULT_RETRY=3'))} to
+have Vitest auto retries on flaky segfaults.\n`))
+    }
+
+    if (i !== retries)
+      console.log(`${c.inverse(c.bold(c.magenta(' Retrying ')))} vitest ${args.join(' ')} ${c.gray(`(${i + 1} of ${retries})`)}`)
+  }
+
+  // retry out
+  process.exit(1)
+}
+
+async function start(preArgs: string[], postArgs: string[]) {
+  const child = execa(
+    'node',
+    [
+      ...preArgs,
+      fileURLToPath(ENTRY),
+      ...postArgs,
+    ],
+    {
+      reject: false,
+      stderr: 'pipe',
+      stdout: 'inherit',
+      stdin: 'inherit',
+      env: {
+        ...process.env,
+        VITEST_CLI_WRAPPER: 'true',
+      },
+    },
+  )
   child.stderr?.pipe(process.stderr)
   const { stderr = '' } = await child
 
-  for (const error of ERRORS) {
+  if (child.exitCode === EXIT_CODE_RESTART)
+    return 'restart'
+
+  for (const error of SegfaultErrors) {
     if (stderr.includes(error.trigger)) {
       if (process.env.GITHUB_ACTIONS)
         console.log(`::warning:: Segmentfault Error Detected: ${error.trigger}\nRefer to ${error.url}`)
-
       const RED_BLOCK = c.inverse(c.red(' '))
       console.log(`\n${c.inverse(c.bold(c.red(' Segmentfault Error Detected ')))}\n${RED_BLOCK} ${c.red(error.trigger)}\n${RED_BLOCK} ${c.red(`Refer to ${error.url}`)}\n`)
-      return
+      return 'error'
     }
   }
 

packages/vitest/src/node/core.ts

@@ -1,12 +1,13 @@
 import { existsSync, promises as fs } from 'fs'
 import type { ViteDevServer } from 'vite'
+import { normalizePath } from 'vite'
 import { relative, toNamespacedPath } from 'pathe'
 import fg from 'fast-glob'
 import mm from 'micromatch'
 import c from 'picocolors'
 import { ViteNodeRunner } from 'vite-node/client'
 import { ViteNodeServer } from 'vite-node/server'
-import type { ArgumentsType, CoverageProvider, Reporter, ResolvedConfig, UserConfig } from '../types'
+import type { ArgumentsType, CoverageProvider, OnServerRestartHandler, Reporter, ResolvedConfig, UserConfig } from '../types'
 import { SnapshotManager } from '../integrations/snapshot/manager'
 import { clearTimeout, deepMerge, hasFailed, noop, setTimeout, slash } from '../utils'
 import { getCoverageProvider } from '../integrations/coverage'
@@ -48,7 +49,7 @@ export class Vitest {
     this.logger = new Logger(this)
   }
 
-  private _onRestartListeners: Array<() => void> = []
+  private _onRestartListeners: OnServerRestartHandler[] = []
 
   async setServer(options: UserConfig, server: ViteDevServer) {
     this.unregisterWatcher?.()
@@ -81,12 +82,29 @@ export class Vitest {
       },
     })
 
+    if (this.config.watch) {
+      // hijack server restart
+      const serverRestart = server.restart
+      server.restart = async (...args) => {
+        await Promise.all(this._onRestartListeners.map(fn => fn()))
+        return await serverRestart(...args)
+      }
+
+      // since we set `server.hmr: false`, Vite does not auto restart itself
+      server.watcher.on('change', async (file) => {
+        file = normalizePath(file)
+        const isConfig = file === server.config.configFile
+        if (isConfig) {
+          await Promise.all(this._onRestartListeners.map(fn => fn('config')))
+          await serverRestart()
+        }
+      })
+    }
+
     this.reporters = await createReporters(resolved.reporters, this.runner)
 
     this.runningPromise = undefined
 
-    this._onRestartListeners.forEach(fn => fn())
-
     await this.coverageProvider?.clean(this.config.coverage.clean)
 
     this.cache.results.setConfig(resolved.root, resolved.cache)
@@ -331,13 +349,6 @@ export class Vitest {
 
       this.isFirstRun = false
 
-      // add previously failed files
-      // if (RERUN_FAILED) {
-      //   ctx.state.getFiles().forEach((file) => {
-      //     if (file.result?.state === 'fail')
-      //       changedTests.add(file.filepath)
-      //   })
-      // }
       this.snapshot.clear()
       const files = Array.from(this.changedTests)
       this.changedTests.clear()
@@ -523,7 +534,7 @@ export class Vitest {
     return code.includes('import.meta.vitest')
   }
 
-  onServerRestarted(fn: () => void) {
+  onServerRestart(fn: OnServerRestartHandler) {
     this._onRestartListeners.push(fn)
   }
 }

packages/vitest/src/node/plugins/index.ts

@@ -11,8 +11,6 @@ import { CSSEnablerPlugin } from './cssEnabler'
 import { CoverageTransform } from './coverageTransform'
 
 export async function VitestPlugin(options: UserConfig = {}, ctx = new Vitest()): Promise<VitePlugin[]> {
-  let haveStarted = false
-
   async function UIPlugin() {
     await ensurePackageInstalled('@vitest/ui', ctx.config?.root || options.root || process.cwd())
     return (await import('@vitest/ui')).default(options.uiBase)
@@ -145,11 +143,8 @@ export async function VitestPlugin(options: UserConfig = {}, ctx = new Vitest())
           process.env[name] ??= envs[name]
       },
       async configureServer(server) {
-        if (haveStarted)
-          await ctx.report('onServerRestart')
         try {
           await ctx.setServer(options, server)
-          haveStarted = true
           if (options.api && options.watch)
             (await import('../../api/setup')).setup(ctx)
         }

packages/vitest/src/node/reporters/base.ts

@@ -180,8 +180,12 @@ export abstract class BaseReporter implements Reporter {
     return true
   }
 
-  onServerRestart() {
-    this.ctx.logger.log(c.cyan('Restarted due to config changes...'))
+  onServerRestart(reason?: string) {
+    this.ctx.logger.log(c.bold(c.magenta(
+      reason === 'config'
+        ? '\nRestarting due to config changes...'
+        : '\nRestarting Vitest...',
+    )))
   }
 
   async reportSummary(files: File[]) {

packages/vitest/src/types/general.ts

@@ -79,3 +79,5 @@ export interface ModuleGraphData {
   externalized: string[]
   inlined: string[]
 }
+
+export type OnServerRestartHandler = (reason?: string) => Promise<void> | void

packages/vitest/src/types/reporter.ts

@@ -13,7 +13,7 @@ export interface Reporter {
   onWatcherStart?: () => Awaitable<void>
   onWatcherRerun?: (files: string[], trigger?: string) => Awaitable<void>
 
-  onServerRestart?: () => Awaitable<void>
+  onServerRestart?: (reason?: string) => Awaitable<void>
 
   onUserConsoleLog?: (log: UserConsoleLog) => Awaitable<void>
 }

packages/vitest/src/utils/index.ts

@@ -5,6 +5,7 @@ import { isPackageExists } from 'local-pkg'
 import { relative as relativeNode } from 'pathe'
 import type { ModuleCacheMap } from 'vite-node'
 import type { Suite, Task } from '../types'
+import { EXIT_CODE_RESTART } from '../constants'
 import { getNames } from './tasks'
 
 export * from './tasks'
@@ -87,7 +88,7 @@ export async function ensurePackageInstalled(
     await (await import('@antfu/install-pkg')).installPackage(dependency, { dev: true })
     // TODO: somehow it fails to load the package after installation, remove this when it's fixed
     process.stderr.write(c.yellow(`\nPackage ${dependency} installed, re-run the command to start.\n`))
-    process.exit(1)
+    process.exit(EXIT_CODE_RESTART)
     return true
   }