Add automated bench script for nested-deps (vercel#29583)

Co-authored-by: JJ Kasper <[email protected]>

bench/nested-deps/bench.mjs

@@ -0,0 +1,199 @@
+import { spawn } from 'child_process'
+import fetch from 'node-fetch'
+import {
+  existsSync,
+  readFileSync,
+  writeFileSync,
+  unlinkSync,
+  promises as fs,
+} from 'fs'
+import treeKill from 'tree-kill'
+
+async function killApp(instance) {
+  await new Promise((resolve, reject) => {
+    treeKill(instance.pid, (err) => {
+      if (err) {
+        if (
+          process.platform === 'win32' &&
+          typeof err.message === 'string' &&
+          (err.message.includes(`no running instance of the task`) ||
+            err.message.includes(`not found`))
+        ) {
+          // Windows throws an error if the process is already stopped
+          //
+          // Command failed: taskkill /pid 6924 /T /F
+          // ERROR: The process with PID 6924 (child process of PID 6736) could not be terminated.
+          // Reason: There is no running instance of the task.
+          return resolve()
+        }
+        return reject(err)
+      }
+
+      resolve()
+    })
+  })
+}
+
+class File {
+  constructor(path) {
+    this.path = path
+    this.originalContent = existsSync(this.path)
+      ? readFileSync(this.path, 'utf8')
+      : null
+  }
+
+  write(content) {
+    if (!this.originalContent) {
+      this.originalContent = content
+    }
+    writeFileSync(this.path, content, 'utf8')
+  }
+
+  replace(pattern, newValue) {
+    const currentContent = readFileSync(this.path, 'utf8')
+    if (pattern instanceof RegExp) {
+      if (!pattern.test(currentContent)) {
+        throw new Error(
+          `Failed to replace content.\n\nPattern: ${pattern.toString()}\n\nContent: ${currentContent}`
+        )
+      }
+    } else if (typeof pattern === 'string') {
+      if (!currentContent.includes(pattern)) {
+        throw new Error(
+          `Failed to replace content.\n\nPattern: ${pattern}\n\nContent: ${currentContent}`
+        )
+      }
+    } else {
+      throw new Error(`Unknown replacement attempt type: ${pattern}`)
+    }
+
+    const newContent = currentContent.replace(pattern, newValue)
+    this.write(newContent)
+  }
+
+  prepend(line) {
+    const currentContent = readFileSync(this.path, 'utf8')
+    this.write(line + '\n' + currentContent)
+  }
+
+  delete() {
+    unlinkSync(this.path)
+  }
+
+  restore() {
+    this.write(this.originalContent)
+  }
+}
+
+function runNextCommandDev(argv, opts = {}) {
+  const nextBin = '../../node_modules/.bin/next'
+  const cwd = process.cwd()
+  const env = {
+    ...process.env,
+    NODE_ENV: undefined,
+    __NEXT_TEST_MODE: 'true',
+    ...opts.env,
+  }
+
+  const nodeArgs = opts.nodeArgs || []
+  return new Promise((resolve, reject) => {
+    const instance = spawn(
+      'node',
+      [...nodeArgs, '--no-deprecation', nextBin, ...argv],
+      {
+        cwd,
+        env,
+      }
+    )
+    let didResolve = false
+
+    function handleStdout(data) {
+      const message = data.toString()
+      const bootupMarkers = {
+        dev: /compiled successfully/i,
+        start: /started server/i,
+      }
+      if (
+        (opts.bootupMarker && opts.bootupMarker.test(message)) ||
+        bootupMarkers[opts.nextStart ? 'start' : 'dev'].test(message)
+      ) {
+        if (!didResolve) {
+          didResolve = true
+          resolve(instance)
+        }
+      }
+
+      if (typeof opts.onStdout === 'function') {
+        opts.onStdout(message)
+      }
+
+      if (opts.stdout !== false) {
+        process.stdout.write(message)
+      }
+    }
+
+    function handleStderr(data) {
+      const message = data.toString()
+      if (typeof opts.onStderr === 'function') {
+        opts.onStderr(message)
+      }
+
+      if (opts.stderr !== false) {
+        process.stderr.write(message)
+      }
+    }
+
+    instance.stdout.on('data', handleStdout)
+    instance.stderr.on('data', handleStderr)
+
+    instance.on('close', () => {
+      instance.stdout.removeListener('data', handleStdout)
+      instance.stderr.removeListener('data', handleStderr)
+      if (!didResolve) {
+        didResolve = true
+        resolve()
+      }
+    })
+
+    instance.on('error', (err) => {
+      reject(err)
+    })
+  })
+}
+
+function waitFor(millis) {
+  return new Promise((resolve) => setTimeout(resolve, millis))
+}
+
+async function main() {
+  await fs.rmDir('.next', { recursive: true })
+  const file = new File('pages/index.jsx')
+  try {
+    const instance = await runNextCommandDev(['dev', '--port', '3000'])
+    const res = await fetch('http://localhost:3000/')
+    if (res.status !== 200) {
+      throw new Error('Fetching / failed')
+    }
+
+    await waitFor(3000)
+
+    file.prepend('// First edit')
+
+    await waitFor(5000)
+
+    file.prepend('// Second edit')
+
+    await waitFor(5000)
+
+    file.prepend('// Third edit')
+
+    await waitFor(5000)
+
+    await killApp(instance)
+    await fs.rmDir('.next', { recursive: true })
+  } finally {
+    file.restore()
+  }
+}
+
+main()