fix(coverage): v8 to ignore Vite's generated cjs import helpers (#8718)

Co-authored-by: Ari Perkkiö <ari.perkkio@gmail.com>

Author: mrginglymus

packages/coverage-v8/src/provider.ts

@@ -244,6 +244,20 @@ export class V8CoverageProvider extends BaseCoverageProvider<ResolvedCoverageOpt
  return true
  }
 
+ // CJS imports as ternaries - e.g.
+ // const React = __vite__cjsImport0_react.__esModule ? __vite__cjsImport0_react.default : __vite__cjsImport0_react;
+ if (
+ type === 'branch'
+ && node.type === 'ConditionalExpression'
+ && node.test.type === 'MemberExpression'
+ && node.test.object.type === 'Identifier'
+ && node.test.object.name.startsWith('__vite__cjsImport')
+ && node.test.property.type === 'Identifier'
+ && node.test.property.name === '__esModule'
+ ) {
+ return true
+ }
+
  // in-source test with "if (import.meta.vitest)"
  if (
  (type === 'branch' || type === 'statement')

pnpm-lock.yaml

@@ -0,0 +1,6 @@
+// @ts-expect-error -- types not picked up for some reason
+import cjsDefault from '@vitest/cjs-lib'
+
+export default function getA() {
+ return cjsDefault.a
+}

test/coverage-test/fixtures/src/cjs-dependency.ts

@@ -0,0 +1,6 @@
+import { test } from "vitest";
+import cjsDependency from "../src/cjs-dependency";
+
+test("cjs dependency vite transforms", () => {
+ cjsDependency()
+})

test/coverage-test/fixtures/test/cjs-dependency.test.ts

@@ -11,6 +11,7 @@
  "@types/istanbul-lib-report": "catalog:",
  "@vitejs/plugin-vue": "latest",
  "@vitest/browser-playwright": "workspace:*",
+ "@vitest/cjs-lib": "file:../browser/cjs-lib",
  "@vitest/coverage-istanbul": "workspace:*",
  "@vitest/coverage-v8": "workspace:*",
  "@vitest/web-worker": "workspace:*",

test/coverage-test/package.json

@@ -0,0 +1,29 @@
+import { fileURLToPath } from 'node:url'
+import { expect } from 'vitest'
+import { readCoverageMap, runVitest, test } from '../utils'
+
+test('excludes Vite transforms done for CJS dependency', async () => {
+ await runVitest({
+ include: ['fixtures/test/cjs-dependency.test.ts'],
+ coverage: {
+ reporter: 'json',
+ },
+ }, undefined, {
+ cacheDir: fileURLToPath(new URL('./node_modules/.vite', import.meta.url)),
+ optimizeDeps: { include: ['@vitest/cjs-lib', '/Users/ari/Git/vitest/test/browser/cjs-lib'] },
+ })
+ const coverageMap = await readCoverageMap()
+ const files = coverageMap.files()
+
+ expect(files).toMatchInlineSnapshot(`
+ [
+ "<process-cwd>/fixtures/src/cjs-dependency.ts",
+ ]
+ `)
+
+ const fileCoverage = coverageMap.fileCoverageFor('<process-cwd>/fixtures/src/cjs-dependency.ts')
+
+ // There should be 0 branches (#8717)
+ expect(Object.keys(fileCoverage.b)).toHaveLength(0)
+ expect(Object.keys(fileCoverage.branchMap)).toHaveLength(0)
+})

test/coverage-test/test/cjs-dependency.test.ts

@@ -6,6 +6,7 @@ const ISTANBUL_TESTS = 'test/**.istanbul.test.ts'
 const CUSTOM_TESTS = 'test/**.custom.test.ts'
 const UNIT_TESTS = 'test/**.unit.test.ts'
 const BROWSER_TESTS = 'test/**.browser.test.ts'
+const FIXTURES = '**/fixtures/**'
 
 const config = defineConfig({
  test: {
@@ -31,6 +32,7 @@ export default defineConfig({
  UNIT_TESTS,
  CUSTOM_TESTS,
  BROWSER_TESTS,
+ FIXTURES,
  ],
  },
  },
@@ -47,6 +49,7 @@ export default defineConfig({
  UNIT_TESTS,
  CUSTOM_TESTS,
  BROWSER_TESTS,
+ FIXTURES,
  ],
  },
  },
@@ -58,6 +61,7 @@ export default defineConfig({
  name: { label: 'custom', color: 'yellow' },
  env: { COVERAGE_PROVIDER: 'custom' },
  include: [CUSTOM_TESTS],
+ exclude: [FIXTURES],
  },
  },
 
@@ -87,7 +91,9 @@ export default defineConfig({
  '**/vue.test.ts',
  '**/in-source.test.ts',
  '**/query-param-transforms.test.ts',
+ '**/test/cjs-dependency.test.ts',
  ],
+ exclude: [FIXTURES],
  },
  },
  {
@@ -115,7 +121,9 @@ export default defineConfig({
  '**/vue.test.ts',
  '**/in-source.test.ts',
  '**/query-param-transforms.test.ts',
+ '**/test/cjs-dependency.test.ts',
  ],
+ exclude: [FIXTURES],
  },
  },