test: add benchmarks for dev server initial build (#30742)

packages/kit/test/write-types.bench.ts

@@ -1,17 +1,25 @@
 import { fileURLToPath } from 'node:url'
-import { afterAll, bench, describe } from 'vitest'
-import { join, normalize } from 'pathe'
+import { rm } from 'node:fs/promises'
+import { afterAll, beforeAll, bench, describe } from 'vitest'
+import { join, normalize, resolve } from 'pathe'
 import { withoutTrailingSlash } from 'ufo'
 import { loadNuxt, writeTypes } from '@nuxt/kit'
+import type { Nuxt } from 'nuxt/schema'
 
-describe('writeTypes', async () => {
+describe('writeTypes', () => {
   const relativeDir = join('../../..', 'test/fixtures/basic-types')
   const path = withoutTrailingSlash(normalize(fileURLToPath(new URL(relativeDir, import.meta.url))))
 
-  const nuxt = await loadNuxt({ cwd: path })
+  let nuxt: Nuxt
+
+  beforeAll(async () => {
+    nuxt = await loadNuxt({ cwd: path })
+    await rm(resolve(path, '.nuxt'), { recursive: true, force: true })
+  }, 20_000)
+
   afterAll(async () => {
     await nuxt.close()
-  })
+  }, 20_000)
 
   bench('writeTypes in the basic-types fixture', async () => {
     await writeTypes(nuxt)

packages/nuxt/test/build.bench.ts

@@ -0,0 +1,33 @@
+import { fileURLToPath } from 'node:url'
+import { rm } from 'node:fs/promises'
+import { beforeAll, bench, describe } from 'vitest'
+import { join, normalize } from 'pathe'
+import { withoutTrailingSlash } from 'ufo'
+import { build, loadNuxt } from 'nuxt'
+
+const basicTestFixtureDir = withoutTrailingSlash(normalize(fileURLToPath(new URL('../../../test/fixtures/basic', import.meta.url))))
+
+describe('build', () => {
+  beforeAll(async () => {
+    await rm(join(basicTestFixtureDir, '.nuxt'), { recursive: true, force: true })
+  })
+
+  bench('initial dev server build in the basic test fixture', async () => {
+    const nuxt = await loadNuxt({
+      cwd: basicTestFixtureDir,
+      ready: true,
+      overrides: {
+        dev: true,
+        sourcemap: false,
+        builder: {
+          bundle: () => Promise.resolve(),
+        },
+      },
+    })
+    await new Promise<void>((resolve) => {
+      nuxt.hook('build:done', () => resolve())
+      build(nuxt)
+    })
+    await nuxt.close()
+  })
+})

packages/nuxt/test/load-nuxt.bench.ts

@@ -1,6 +1,7 @@
 import { fileURLToPath } from 'node:url'
-import { bench, describe } from 'vitest'
-import { normalize } from 'pathe'
+import { rm } from 'node:fs/promises'
+import { beforeAll, bench, describe } from 'vitest'
+import { join, normalize } from 'pathe'
 import { withoutTrailingSlash } from 'ufo'
 import { loadNuxt } from 'nuxt'
 
@@ -8,6 +9,13 @@ const emptyDir = withoutTrailingSlash(normalize(fileURLToPath(new URL('../../../
 const basicTestFixtureDir = withoutTrailingSlash(normalize(fileURLToPath(new URL('../../../test/fixtures/basic', import.meta.url))))
 
 describe('loadNuxt', () => {
+  beforeAll(async () => {
+    await Promise.all([
+      rm(join(emptyDir, '.nuxt'), { recursive: true, force: true }),
+      rm(join(basicTestFixtureDir, '.nuxt'), { recursive: true, force: true }),
+    ])
+  })
+
   bench('loadNuxt in an empty directory', async () => {
     const nuxt = await loadNuxt({
       cwd: emptyDir,