feat(coverage): switch to @vitest/istanbuljs packages (#11053)

Author: AriPerkkio

AGENTS.md

@@ -202,7 +202,7 @@ Other blocking CI jobs:
 - Add deps with `pnpm add <pkg>` inside the target package: `catalogMode: prefer` writes `catalog:` into package.json and adds the version to the default catalog in `pnpm-workspace.yaml` automatically. To bump a shared dep, edit its catalog entry, never per-package ranges.
 - The `overrides` in `pnpm-workspace.yaml` force one version of `vite`, `rollup`, `@types/node`, `acorn`, and `mlly` across the workspace; editing a range in an individual package.json changes what gets published, not what installs locally.
 - The workspace develops against the latest supported Vite major, but `vitest` supports the full peer range and CI runs a dedicated job against the previous major (`pnpm override-vite7` reproduces it locally). Do not rely on newest-Vite-only APIs without a fallback.
-- Deps listed under `patchedDependencies` (`acorn`, `cac`, `@sinonjs/fake-timers`, `rrweb-snapshot`, istanbul-lib-*) are version-locked. Bumping one requires regenerating the patch with `pnpm patch` and updating the version-keyed entry in `pnpm-workspace.yaml`.
+- Deps listed under `patchedDependencies` (`acorn`, `cac`, `@sinonjs/fake-timers`, `rrweb-snapshot`) are version-locked. Bumping one requires regenerating the patch with `pnpm patch` and updating the version-keyed entry in `pnpm-workspace.yaml`.
 - Dependency build scripts run only for packages listed under `allowBuilds` in `pnpm-workspace.yaml`; a new dep with a postinstall step installs unbuilt unless added there.
 - pnpm enforces a 24h `minimumReleaseAge`: installing a version published less than a day ago either resolves to an older version or appends the pick to `minimumReleaseAgeExclude` in `pnpm-workspace.yaml`. Both outcomes are expected; commit the yaml change instead of reverting it.
 

docs/api/advanced/reporters.md

@@ -187,10 +187,10 @@ export default new MyReporter()
 function onCoverage(coverage: unknown): Awaitable<void>
 ```
 
-This hook is called after coverage results have been processed. Coverage provider's reporters are called after this hook. The typings of `coverage` depends on the `coverage.provider`. For Vitest's default built-in providers you can import the types from `istanbul-lib-coverage` package:
+This hook is called after coverage results have been processed. Coverage provider's reporters are called after this hook. The typings of `coverage` depends on the `coverage.provider`. For Vitest's default built-in providers you can import the types from `@vitest/istanbul-lib-coverage` package:
 
 ```ts
-import type { CoverageMap } from 'istanbul-lib-coverage'
+import type { CoverageMap } from '@vitest/istanbul-lib-coverage'
 
 declare function onCoverage(coverage: CoverageMap): Awaitable<void>
 ```

docs/config/coverage.md

@@ -98,7 +98,7 @@ Directory to write coverage report to.
 - **Available for providers:** `'v8' | 'istanbul'`
 - **CLI:** `--coverage.reporter=<reporter>`, `--coverage.reporter=<reporter1> --coverage.reporter=<reporter2>`
 
-Coverage reporters to use. See [istanbul documentation](https://istanbul.js.org/docs/advanced/alternative-reporters/) for detailed list of all reporters. See [`@types/istanbul-reports`](https://github.com/DefinitelyTyped/DefinitelyTyped/blob/276d95e4304b3670eaf6e8e5a7ea9e265a14e338/types/istanbul-reports/index.d.ts) for details about reporter specific options.
+Coverage reporters to use. See [istanbul documentation](https://istanbul.js.org/docs/advanced/alternative-reporters/) for detailed list of all reporters. See [`@vitest/istanbul-lib-report`](https://github.com/vitest-dev/istanbuljs/tree/main/packages/istanbul-lib-report/src/reports) for details about reporter specific options.
 
 The reporter has three different types:
 
@@ -459,7 +459,7 @@ Concurrency limit used when processing the coverage results.
 - **Type:** `(options: InstrumenterOptions) => CoverageInstrumenter`
 - **Available for providers:** `'istanbul'`
 
-Factory for a custom instrumenter to use in place of the default `istanbul-lib-instrument`. Vitest calls the factory once during initialization and reuses the returned instrumenter for every file. The rest of the Istanbul pipeline (collection, merging, reporting) is unchanged.
+Factory for a custom instrumenter to use in place of the default `@vitest/istanbul-lib-instrument`. Vitest calls the factory once during initialization and reuses the returned instrumenter for every file. The rest of the Istanbul pipeline (collection, merging, reporting) is unchanged.
 
 The factory receives an `InstrumenterOptions` object with Vitest's runtime coverage settings, and must return an object implementing the `CoverageInstrumenter` interface. Both types are exported from `vitest/node`.
 

docs/guide/coverage.md

@@ -257,10 +257,36 @@ export default defineConfig({
 })
 ```
 
-Custom reporters are loaded by Istanbul and must match its reporter interface. See [built-in reporters' implementation](https://github.com/istanbuljs/istanbuljs/tree/master/packages/istanbul-reports/lib) for reference.
+Custom reporters are loaded by `@vitest/istanbul-lib-report` and must match its reporter interface. See [built-in reporters' implementation](https://github.com/vitest-dev/istanbuljs/tree/main/packages/istanbul-lib-report/src/reports) for reference.
 
+::: code-group
+```js [custom-reporter.mjs]
+import { ReportBase } from '@vitest/istanbul-lib-report'
+
+export default class CustomReporter extends ReportBase {
+  constructor(opts) {
+    super()
+
+    if (!opts.file) {
+      throw new Error('File is required as custom reporter parameter')
+    }
+
+    this.file = opts.file
+  }
+
+  onStart(root, context) {
+    this.contentWriter = context.writer.writeFile(this.file)
+    this.contentWriter.println('Start of custom coverage report ESM')
+  }
+
+  onEnd() {
+    this.contentWriter.println('End of custom coverage report ESM')
+    this.contentWriter.close()
+  }
+}
+```
 ```js [custom-reporter.cjs]
-const { ReportBase } = require('istanbul-lib-report')
+const { ReportBase } = require('@vitest/istanbul-lib-report')
 
 module.exports = class CustomReporter extends ReportBase {
   constructor(opts) {
@@ -281,6 +307,7 @@ module.exports = class CustomReporter extends ReportBase {
   }
 }
 ```
+:::
 
 ## Custom Coverage Provider
 

knip.jsonc

@@ -64,8 +64,7 @@
       ]
     },
     "packages/coverage-istanbul": {
-      "entry": ["src/{browser,index,provider}.ts"],
-      "ignoreDependencies": ["@babel/core"]
+      "entry": ["src/{browser,index,provider}.ts"]
     },
     "packages/coverage-v8": {
       "entry": ["src/{browser,index,provider}.ts"],

packages/coverage-istanbul/package.json

@@ -48,25 +48,17 @@
     "vitest": "workspace:*"
   },
   "dependencies": {
-    "@babel/core": "^7.29.7",
-    "@istanbuljs/schema": "^0.1.6",
     "@jridgewell/gen-mapping": "^0.3.13",
     "@jridgewell/trace-mapping": "catalog:",
-    "istanbul-lib-coverage": "catalog:",
-    "istanbul-lib-report": "catalog:",
-    "istanbul-reports": "catalog:",
+    "@vitest/istanbul-lib-coverage": "catalog:",
+    "@vitest/istanbul-lib-instrument": "^1.0.0",
+    "@vitest/istanbul-lib-report": "catalog:",
+    "@vitest/istanbul-lib-source-maps": "^1.0.0",
     "magicast": "catalog:",
     "obug": "catalog:",
     "tinyrainbow": "catalog:"
   },
   "devDependencies": {
-    "@types/istanbul-lib-coverage": "catalog:",
-    "@types/istanbul-lib-instrument": "^1.7.8",
-    "@types/istanbul-lib-report": "catalog:",
-    "@types/istanbul-lib-source-maps": "catalog:",
-    "@types/istanbul-reports": "catalog:",
-    "istanbul-lib-instrument": "^6.0.3",
-    "istanbul-lib-source-maps": "catalog:",
     "pathe": "catalog:",
     "vitest": "workspace:*"
   }

packages/coverage-istanbul/rollup.config.js

@@ -1,5 +1,4 @@
 import { builtinModules, createRequire } from 'node:module'
-import commonjs from '@rollup/plugin-commonjs'
 import json from '@rollup/plugin-json'
 import nodeResolve from '@rollup/plugin-node-resolve'
 import { join } from 'pathe'
@@ -21,9 +20,6 @@ const external = [
   ...Object.keys(pkg.dependencies || {}),
   ...Object.keys(pkg.peerDependencies || {}),
   /^@?vitest(\/|$)/,
-
-  // We bundle istanbul-lib-instrument but don't want to bundle its babel dependency
-  '@babel/core',
 ]
 
 const dtsUtils = createDtsUtils()
@@ -32,11 +28,6 @@ const plugins = [
   ...dtsUtils.isolatedDecl(),
   nodeResolve(),
   json(),
-  commonjs({
-    // "istanbul-lib-source-maps > @jridgewell/trace-mapping" is not CJS
-    // "istanbul-lib-instrument > @jridgewell/trace-mapping" is not CJS
-    esmExternals: ['@jridgewell/trace-mapping'],
-  }),
   oxc({
     transform: { target: 'node20' },
   }),
@@ -62,16 +53,5 @@ export default defineConfig(() => [
     watch: false,
     external,
     plugins: dtsUtils.dts(),
-    onLog(level, log, handler) {
-      // we don't control the source of "istanbul-lib-coverage"
-      if (
-        level === 'warn'
-        && log.exporter === 'istanbul-lib-coverage'
-        && log.message.includes('"Range" is imported')
-      ) {
-        return
-      }
-      handler(level, log)
-    },
   },
 ])

packages/coverage-istanbul/src/base.ts

@@ -1,4 +1,4 @@
-import type { CoverageMapData } from 'istanbul-lib-coverage'
+import type { CoverageMapData } from '@vitest/istanbul-lib-coverage'
 import type { IstanbulCoverageProvider } from './provider'
 import { COVERAGE_STORE_KEY } from './constants'
 

packages/coverage-istanbul/src/provider.ts

@@ -1,17 +1,14 @@
-import type { CoverageMap } from 'istanbul-lib-coverage'
-import type { Instrumenter } from 'istanbul-lib-instrument'
+import type { CoverageMap } from '@vitest/istanbul-lib-coverage'
+import type { Instrumenter } from '@vitest/istanbul-lib-instrument'
 import type { ProxifiedModule } from 'magicast'
 import type { CoverageProvider, ReportContext, Vite, Vitest } from 'vitest/node'
 import { existsSync, promises as fs } from 'node:fs'
-// @ts-expect-error missing types
-import { defaults as istanbulDefaults } from '@istanbuljs/schema'
 import { addMapping, GenMapping, toEncodedMap } from '@jridgewell/gen-mapping'
 import { eachMapping, TraceMap } from '@jridgewell/trace-mapping'
-import libCoverage from 'istanbul-lib-coverage'
-import { createInstrumenter } from 'istanbul-lib-instrument'
-import libReport from 'istanbul-lib-report'
-import libSourceMaps from 'istanbul-lib-source-maps'
-import reports from 'istanbul-reports'
+import * as libCoverage from '@vitest/istanbul-lib-coverage'
+import { createInstrumenter } from '@vitest/istanbul-lib-instrument'
+import * as libReport from '@vitest/istanbul-lib-report'
+import * as libSourceMaps from '@vitest/istanbul-lib-source-maps'
 import { parseModule } from 'magicast'
 import { createDebug } from 'obug'
 import c from 'tinyrainbow'
@@ -58,16 +55,6 @@ export class IstanbulCoverageProvider extends BaseCoverageProvider implements Co
         coverageGlobalScope: 'globalThis',
         coverageGlobalScopeFunc: false,
         ignoreClassMethods: this.options.ignoreClassMethods,
-        parserPlugins: [
-          ...istanbulDefaults.instrumenter.parserPlugins,
-          ['importAttributes', { deprecatedAssertSyntax: true }],
-        ],
-        generatorOpts: {
-          // @ts-expect-error missing type
-          importAttributesKeyword: 'with',
-        },
-
-        // Custom option from the patched istanbul-lib-instrument: https://github.com/istanbuljs/istanbuljs/pull/835
         ignoreLines: true,
       })
     }
@@ -206,13 +193,14 @@ export class IstanbulCoverageProvider extends BaseCoverageProvider implements Co
 
     for (const reporter of this.options.reporter) {
       // Type assertion required for custom reporters
-      reports
-        .create(reporter[0] as Parameters<typeof reports.create>[0], {
+      const reportInstance = await libReport
+        .createAsync(reporter[0] as Parameters<typeof libReport.create>[0], {
           skipFull: this.options.skipFull,
           projectRoot: this.ctx.config.root,
           ...reporter[1],
         })
-        .execute(context)
+
+      reportInstance.execute(context)
     }
 
     if (this.options.thresholds) {

packages/coverage-v8/package.json

@@ -55,19 +55,15 @@
   },
   "dependencies": {
     "@bcoe/v8-coverage": "^1.0.2",
+    "@vitest/istanbul-lib-coverage": "catalog:",
+    "@vitest/istanbul-lib-report": "catalog:",
     "ast-v8-to-istanbul": "^1.0.5",
-    "istanbul-lib-coverage": "catalog:",
-    "istanbul-lib-report": "catalog:",
-    "istanbul-reports": "catalog:",
     "magicast": "catalog:",
     "obug": "catalog:",
     "std-env": "catalog:",
     "tinyrainbow": "catalog:"
   },
   "devDependencies": {
-    "@types/istanbul-lib-coverage": "catalog:",
-    "@types/istanbul-lib-report": "catalog:",
-    "@types/istanbul-reports": "catalog:",
     "@vitest/browser": "workspace:*",
     "@vitest/browser-playwright": "workspace:*",
     "pathe": "catalog:",