[node] Use vitest for unit tests (#11631)

Similar to #11302, but for the `@vercel/node` package.

.changeset/smooth-teachers-knock.md

@@ -0,0 +1,2 @@
+---
+---

packages/node/package.json

@@ -12,9 +12,10 @@
   "scripts": {
     "build": "node build.mjs",
     "test": "cross-env NODE_OPTIONS=--experimental-vm-modules jest --env node --verbose --bail --runInBand",
-    "test-unit": "pnpm test test/unit",
     "test-e2e": "pnpm test test/integration",
-    "type-check": "tsc --noEmit"
+    "type-check": "tsc --noEmit",
+    "vitest-unit-run": "vitest",
+    "vitest-unit": "glob --absolute 'test/unit/**/*.test.ts' 'test/unit/**/*.test.mts'"
   },
   "files": [
     "dist"
@@ -51,13 +52,17 @@
     "@types/etag": "1.8.0",
     "@types/jest": "29.5.0",
     "@vercel/functions": "workspace:*",
+    "@vitest/expect": "1.4.0",
     "content-type": "1.0.5",
     "cookie": "0.4.0",
     "cross-env": "7.0.3",
     "execa": "3.2.0",
     "fs-extra": "11.1.0",
+    "glob": "10.3.16",
     "jest-junit": "16.0.0",
     "source-map-support": "0.5.12",
-    "tree-kill": "1.2.2"
+    "tree-kill": "1.2.2",
+    "vite": "5.1.6",
+    "vitest": "1.3.1"
   }
 }

packages/node/src/index.ts

@@ -317,7 +317,7 @@ async function compile(
   const babelCompileEnabled =
     !isEdgeFunction || process.env.VERCEL_EDGE_NO_BABEL !== '1';
   if (babelCompileEnabled && esmPaths.length) {
-    const babelCompile = require('./babel').compile;
+    const babelCompile = (await import('./babel.js')).compile;
     for (const path of esmPaths) {
       const pathDir = join(workPath, dirname(path));
       if (!pkgCache.has(pathDir)) {
@@ -348,7 +348,7 @@ async function compile(
         );
       }
       console.log(`Compiling "${filename}" from ESM to CommonJS...`);
-      const { code, map } = babelCompile(filename, source);
+      const { code, map } = babelCompile(filename, String(source));
       shouldAddSourcemapSupport = true;
       preparedFiles[path] = new FileBlob({
         data: `${code}\n//# sourceMappingURL=${filename}.map`,

packages/node/test/unit/dev.test.ts

@@ -1,3 +1,4 @@
+import { afterAll, describe, expect, test, vi } from 'vitest';
 import { forkDevServer, readMessage } from '../../src/fork-dev-server';
 import { resolve, extname } from 'path';
 import { createServer } from 'http';
@@ -7,7 +8,7 @@ import { fetch } from 'undici';
 import { promisify } from 'util';
 import { setTimeout } from 'timers/promises';
 
-jest.setTimeout(20 * 1000);
+vi.setConfig({ testTimeout: 20 * 1000 });
 
 const [NODE_MAJOR] = process.versions.node.split('.').map(v => Number(v));
 

packages/node/test/unit/edge-handler/edge-handler-template.test.mts

@@ -1,9 +1,9 @@
+import { describe, test, expect } from 'vitest';
 import { Headers, Response, Request } from 'node-fetch';
 import {
   getUrl,
   respond,
-  // @ts-ignore - this is a special patch file to allow importing from the template
-} from '../../../src/edge-functions/edge-handler-template.mjs';
+} from '../../../src/edge-functions/edge-handler-template.js';
 
 describe('edge-handler-template', () => {
   describe('getUrl()', () => {

packages/node/test/unit/edge-handler/edge-matcher.test.ts

@@ -1,3 +1,4 @@
+import { describe, it, expect } from 'vitest';
 import { prepareFilesystem } from '../test-utils';
 import { build } from '../../../src';
 

packages/node/test/unit/edge-handler/edge-wasm-plugin.test.mts

@@ -1,4 +1,5 @@
-import { createEdgeWasmPlugin } from '../../../dist/edge-functions/edge-wasm-plugin.mjs';
+import { test, expect } from 'vitest';
+import { createEdgeWasmPlugin } from '../../../src/edge-functions/edge-wasm-plugin.mjs';
 import { prepareFilesystem } from '../test-utils';
 import { build } from 'esbuild';
 import { join } from 'path';

packages/node/test/unit/prepare-cache.test.ts

@@ -1,3 +1,4 @@
+import { describe, test, expect } from 'vitest';
 import path from 'path';
 import assert from 'assert';
 import { prepareCache } from '../../src';

packages/node/test/unit/serverless-functions/helpers.test.ts

@@ -1,3 +1,4 @@
+import { describe, it, expect } from 'vitest';
 import { getBodyParser } from '../../../src/serverless-functions/helpers';
 
 describe('serverless-functions/helpers', () => {

packages/node/test/unit/utils.test.ts

@@ -1,3 +1,4 @@
+import { describe, expect, test } from 'vitest';
 import { entrypointToOutputPath } from '../../src/utils';
 
 describe('entrypointToOutputPath()', () => {

packages/node/vitest.config.mts

@@ -0,0 +1,26 @@
+/// <reference types="vitest" />
+import { defineConfig } from 'vite';
+
+export default defineConfig({
+  test: {
+    // Use of process.chdir prohibits usage of the default "threads". https://vitest.dev/config/#forks
+    pool: 'forks',
+    env: {
+      // Vitest supresses color output when `process.env.CI` is true
+      // so override that behavior
+      // Issue: https://github.com/vitest-dev/vitest/issues/2732
+      // Fix: https://github.com/JoshuaKGoldberg/expect-no-axe-violations/pull/3/files
+      FORCE_COLOR: '1',
+    },
+    exclude: [
+      // default
+      '**/node_modules/**',
+      '**/dist/**',
+      '**/cypress/**',
+      '**/.{idea,git,cache,output,temp}/**',
+      '**/{karma,rollup,webpack,vite,vitest,jest,ava,babel,nyc,cypress,tsup,build}.config.*',
+      // some artifacts in the fixtures have spec files that we're not using
+      '**/*.spec.js',
+    ],
+  },
+});