fix(coverage): expensive regexp hangs v8 report generation (#5259)

Author: AriPerkkio

examples/nestjs/package.json

@@ -0,0 +1,22 @@
+{
+  "name": "@vitest/example-nestjs",
+  "type": "module",
+  "private": true,
+  "license": "MIT",
+  "main": "index.js",
+  "scripts": {
+    "test": "vitest",
+    "test:ui": "vitest --ui",
+    "test:run": "vitest run"
+  },
+  "devDependencies": {
+    "@nestjs/common": "^10.3.3",
+    "@nestjs/testing": "^10.3.3",
+    "@vitest/coverage-v8": "^1.3.1",
+    "unplugin-swc": "^1.4.4",
+    "vitest": "1.3.1"
+  },
+  "stackblitz": {
+    "startCommand": "npm run test:ui"
+  }
+}

examples/nestjs/src/cats.controller.ts

@@ -0,0 +1,17 @@
+import { Body, Controller, Get, Post } from '@nestjs/common'
+import type { Cat, CatsService } from './cats.service'
+
+@Controller('cats')
+export class CatsController {
+  constructor(private catsService: CatsService) {}
+
+  @Post()
+  async create(@Body() createCatDto: Cat) {
+    this.catsService.create(createCatDto)
+  }
+
+  @Get()
+  async findAll(): Promise<Cat[]> {
+    return this.catsService.findAll()
+  }
+}

examples/nestjs/src/cats.service.ts

@@ -0,0 +1,20 @@
+import { Injectable } from '@nestjs/common'
+
+export interface Cat {
+  name: string
+  age: number
+  breed: string
+}
+
+@Injectable()
+export class CatsService {
+  private readonly cats: Cat[] = []
+
+  create(cat: Cat) {
+    this.cats.push(cat)
+  }
+
+  findAll(): Cat[] {
+    return this.cats
+  }
+}

examples/nestjs/test/nestjs.test.ts

@@ -0,0 +1,23 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { CatsController } from '../src/cats.controller'
+import type { Cat } from '../src/cats.service'
+import { CatsService } from '../src/cats.service'
+
+describe('CatsController', () => {
+  let catsController: CatsController
+  let catsService: CatsService
+
+  beforeEach(() => {
+    catsService = new CatsService()
+    catsController = new CatsController(catsService)
+  })
+
+  describe('findAll', () => {
+    it('should return an array of cats', async () => {
+      const result = ['test'] as unknown as Cat[]
+      vi.spyOn(catsService, 'findAll').mockImplementation(() => result)
+
+      expect(await catsController.findAll()).toBe(result)
+    })
+  })
+})

examples/nestjs/tsconfig.json

@@ -0,0 +1,6 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "experimentalDecorators": true
+  }
+}

examples/nestjs/vitest.config.ts

@@ -0,0 +1,32 @@
+import swc from 'unplugin-swc'
+import { defineConfig } from 'vitest/config'
+
+export default defineConfig({
+  plugins: [
+    swc.vite({
+      jsc: {
+        target: 'esnext',
+        parser: {
+          syntax: 'typescript',
+          decorators: true,
+        },
+        transform: {
+          legacyDecorator: true,
+          decoratorMetadata: true,
+        },
+      },
+    }),
+  ],
+  test: {
+    coverage: {
+      enabled: true,
+      provider: 'v8',
+      thresholds: {
+        branches: 100,
+        functions: 57.14,
+        lines: 81.08,
+        statements: 81.08,
+      },
+    },
+  },
+})

packages/coverage-v8/src/provider.ts

@@ -51,7 +51,7 @@ const WRAPPER_LENGTH = 185
 
 // Note that this needs to match the line ending as well
 const VITE_EXPORTS_LINE_PATTERN = /Object\.defineProperty\(__vite_ssr_exports__.*\n/g
-const DECORATOR_METADATA_PATTERN = /_ts_metadata\("design:paramtypes"(\s|.)+?]\),/g
+const DECORATOR_METADATA_PATTERN = /_ts_metadata\("design:paramtypes", \[[^\]]*?\]\),*/g
 const DEFAULT_PROJECT = Symbol.for('default-project')
 
 const debug = createDebug('vitest:coverage')