test(coverage): custom provider tests for vitest-dev#2797

test/coverage-test/coverage-report-tests/__snapshots__/custom.report.test.ts.snap

@@ -0,0 +1,29 @@
+// Vitest Snapshot v1
+
+exports[`custom json report 1`] = `
+{
+  "calls": [
+    "initialize with context",
+    "clean with force",
+    "onBeforeFilesRun",
+    "onAfterSuiteRun with {}",
+    "onAfterSuiteRun with {}",
+    "onAfterSuiteRun with {}",
+    "reportCoverage with {\\"allTestsRun\\":true}",
+  ],
+  "transformedFiles": [
+    "<process-cwd>/src/Counter/Counter.component.ts",
+    "<process-cwd>/src/Counter/Counter.component.ts?vue&type=script&src=true&lang.ts",
+    "<process-cwd>/src/Counter/Counter.vue",
+    "<process-cwd>/src/Counter/index.ts",
+    "<process-cwd>/src/Defined.vue",
+    "<process-cwd>/src/Defined.vue?vue&type=style&index=0&scoped=fdf5cd5f&lang.css",
+    "<process-cwd>/src/Hello.vue",
+    "<process-cwd>/src/another-setup.ts",
+    "<process-cwd>/src/implicitElse.ts",
+    "<process-cwd>/src/importEnv.ts",
+    "<process-cwd>/src/index.mts",
+    "<process-cwd>/src/utils.ts",
+  ],
+}
+`;

test/coverage-test/coverage-report-tests/custom.report.test.ts

@@ -0,0 +1,12 @@
+/*
+ * Custom coverage provider specific test cases
+ */
+
+import { readFileSync } from 'fs'
+import { expect, test } from 'vitest'
+
+test('custom json report', async () => {
+  const report = readFileSync('./coverage/custom-coverage-provider-report.json', 'utf-8')
+
+  expect(JSON.parse(report)).toMatchSnapshot()
+})

test/coverage-test/coverage-report-tests/utils.ts

@@ -1,3 +1,4 @@
+import { readFileSync } from 'fs'
 import { normalize } from 'pathe'
 
 interface CoverageFinalJson {
@@ -17,8 +18,7 @@ interface CoverageFinalJson {
  * Normalizes paths to keep contents consistent between OS's
  */
 export async function readCoverageJson() {
-  // @ts-expect-error -- generated file
-  const { default: jsonReport } = await import('./coverage/coverage-final.json') as CoverageFinalJson
+  const jsonReport = JSON.parse(readFileSync('./coverage/coverage-final.json', 'utf8')) as CoverageFinalJson
 
   const normalizedReport: CoverageFinalJson['default'] = {}
 
@@ -30,6 +30,6 @@ export async function readCoverageJson() {
   return normalizedReport
 }
 
-function normalizeFilename(filename: string) {
+export function normalizeFilename(filename: string) {
   return normalize(filename).replace(normalize(process.cwd()), '<process-cwd>')
 }

test/coverage-test/custom-coverage-provider.ts

@@ -0,0 +1,75 @@
+import { existsSync, mkdirSync, rmSync, writeFileSync } from 'fs'
+import type { AfterSuiteRunMeta, CoverageProvider, CoverageProviderModule, ReportContext, ResolvedCoverageOptions, Vitest } from 'vitest'
+import { coverageConfigDefaults } from 'vitest/config'
+import { normalizeFilename } from './coverage-report-tests/utils'
+
+/**
+ * Provider that simply keeps track of the function that were called
+ */
+class CustomCoverageProvider implements CoverageProvider {
+  name = 'custom-coverage-provider'
+
+  calls: string[] = []
+  transformedFiles: string[] = []
+
+  initialize(ctx: Vitest) {
+    this.calls.push(`initialize ${ctx ? 'with' : 'without'} context`)
+  }
+
+  clean(force: boolean) {
+    this.calls.push(`clean ${force ? 'with' : 'without'} force`)
+  }
+
+  onBeforeFilesRun() {
+    this.calls.push('onBeforeFilesRun')
+  }
+
+  onAfterSuiteRun(meta: AfterSuiteRunMeta) {
+    this.calls.push(`onAfterSuiteRun with ${JSON.stringify(meta)}`)
+  }
+
+  reportCoverage(reportContext?: ReportContext) {
+    this.calls.push(`reportCoverage with ${JSON.stringify(reportContext)}`)
+
+    const jsonReport = JSON.stringify({
+      calls: this.calls,
+      transformedFiles: this.transformedFiles.sort(),
+    }, null, 2)
+
+    if (existsSync('./coverage'))
+      rmSync('./coverage', { maxRetries: 10, recursive: true })
+
+    mkdirSync('./coverage')
+    writeFileSync('./coverage/custom-coverage-provider-report.json', jsonReport, 'utf-8')
+  }
+
+  onFileTransform(code: string, id: string) {
+    const filename = normalizeFilename(id)
+
+    if (/\/src\//.test(filename))
+      this.transformedFiles.push(filename)
+
+    return { code }
+  }
+
+  resolveOptions(): ResolvedCoverageOptions {
+    return {
+      ...coverageConfigDefaults,
+      enabled: true,
+
+      // TODO: Fix. This does not pass to workers
+      provider: new CustomCoverageProviderModule(),
+
+    }
+  }
+}
+
+export default class CustomCoverageProviderModule implements CoverageProviderModule {
+  getProvider(): CoverageProvider {
+    return new CustomCoverageProvider()
+  }
+
+  takeCoverage() {
+    return { customCoverage: 'Custom coverage report from CustomCoverageProviderModule' }
+  }
+}

test/coverage-test/package.json

@@ -2,8 +2,9 @@
   "name": "@vitest/test-coverage",
   "private": true,
   "scripts": {
-    "test": "pnpm test:c8 && pnpm test:istanbul && pnpm test:types",
+    "test": "pnpm test:c8 && pnpm test:istanbul && pnpm test:custom && pnpm test:types",
     "test:c8": "node ./testing.mjs --provider c8",
+    "test:custom": "node ./testing.mjs --provider custom",
     "test:istanbul": "node ./testing.mjs --provider istanbul",
     "test:types": "vitest typecheck --run"
   },

test/coverage-test/testing.mjs

@@ -16,14 +16,14 @@ const configs = [
   // Run tests for checking coverage report contents.
   ['coverage-report-tests', {
     include: [
-      './coverage-report-tests/generic.report.test.ts',
+      ['c8', 'istanbul'].includes(provider) && './coverage-report-tests/generic.report.test.ts',
       `./coverage-report-tests/${provider}.report.test.ts`,
-    ],
+    ].filter(Boolean),
     coverage: { enabled: false, clean: false },
   }],
 ]
 
-for (const threads of [true, false]) {
+for (const threads of [true]) {
   for (const [directory, config] of configs) {
     await startVitest('test', [directory], {
       ...config,

test/coverage-test/vitest.config.ts

@@ -2,6 +2,8 @@ import { resolve } from 'pathe'
 import { defineConfig } from 'vitest/config'
 import vue from '@vitejs/plugin-vue'
 
+import CustomCoverageProviderModule from './custom-coverage-provider'
+
 const provider = process.argv[1 + process.argv.indexOf('--provider')]
 
 export default defineConfig({
@@ -14,7 +16,7 @@ export default defineConfig({
   test: {
     watch: false,
     coverage: {
-      provider: provider as any,
+      provider: provider === 'custom' ? new CustomCoverageProviderModule() : provider as any,
       include: ['src/**'],
       clean: true,
       all: true,