From 4e655268c958c9c49cf3516b096b3244f56ed998 Mon Sep 17 00:00:00 2001
From: AriPerkkio <ari.perkkio@gmail.com>
Date: Fri, 21 Jul 2023 09:22:24 +0300
Subject: [PATCH] fix(coverage): exclude vite virtual files by default

---
 docs/config/index.md                             |  1 +
 packages/vitest/src/defaults.ts                  |  1 +
 .../coverage-report-tests/generic.report.test.ts |  8 ++++++++
 test/coverage-test/test/coverage.test.ts         |  7 +++++++
 test/coverage-test/vitest.config.ts              | 16 ++++++++++++++++
 5 files changed, 33 insertions(+)

diff --git a/docs/config/index.md b/docs/config/index.md
index 30e83dacbc33..d350291a7b13 100644
--- a/docs/config/index.md
+++ b/docs/config/index.md
@@ -720,6 +720,7 @@ List of files included in coverage as glob patterns
   'dist/**',
   'packages/*/test?(s)/**',
   '**/*.d.ts',
+  '**/virtual:*',
   'cypress/**',
   'test?(s)/**',
   'test?(-*).?(c|m)[jt]s?(x)',
diff --git a/packages/vitest/src/defaults.ts b/packages/vitest/src/defaults.ts
index 10040a9486dc..a0556dfada3f 100644
--- a/packages/vitest/src/defaults.ts
+++ b/packages/vitest/src/defaults.ts
@@ -15,6 +15,7 @@ const defaultCoverageExcludes = [
   'dist/**',
   'packages/*/test?(s)/**',
   '**/*.d.ts',
+  '**/virtual:*',
   'cypress/**',
   'test?(s)/**',
   'test?(-*).?(c|m)[jt]s?(x)',
diff --git a/test/coverage-test/coverage-report-tests/generic.report.test.ts b/test/coverage-test/coverage-report-tests/generic.report.test.ts
index c9b62ddce129..1da66bc6a6c5 100644
--- a/test/coverage-test/coverage-report-tests/generic.report.test.ts
+++ b/test/coverage-test/coverage-report-tests/generic.report.test.ts
@@ -101,3 +101,11 @@ test('coverage provider does not conflict with built-in reporter\'s outputFile',
 
   expect(files).toContain('junit.xml')
 })
+
+test('virtual files should be excluded', () => {
+  const files = fs.readdirSync(resolve('./coverage'))
+  const srcFiles = fs.readdirSync(resolve('./coverage/src'))
+
+  for (const file of [...files, ...srcFiles])
+    expect(file).not.toContain('virtual:')
+})
diff --git a/test/coverage-test/test/coverage.test.ts b/test/coverage-test/test/coverage.test.ts
index 6d3e20f399a3..8d841ae26312 100644
--- a/test/coverage-test/test/coverage.test.ts
+++ b/test/coverage-test/test/coverage.test.ts
@@ -1,4 +1,7 @@
 import { expect, test } from 'vitest'
+
+// @ts-expect-error -- untyped virtual file provided by custom plugin
+import virtualFile from 'virtual:vitest-custom-virtual-file'
 import { implicitElse } from '../src/implicitElse'
 import { useImportEnv } from '../src/importEnv'
 import { second } from '../src/function-count'
@@ -40,3 +43,7 @@ test.skipIf(skipDynamicFiles)('run dynamic ESM file', async () => {
 test.skipIf(skipDynamicFiles)('run dynamic CJS file', async () => {
   await runDynamicFileCJS()
 })
+
+test('virtual file import', () => {
+  expect(virtualFile).toBe('This file should be excluded from coverage report')
+})
diff --git a/test/coverage-test/vitest.config.ts b/test/coverage-test/vitest.config.ts
index 0eb103425292..52f79a0fb820 100644
--- a/test/coverage-test/vitest.config.ts
+++ b/test/coverage-test/vitest.config.ts
@@ -7,6 +7,22 @@ const provider = process.argv[1 + process.argv.indexOf('--provider')]
 export default defineConfig({
   plugins: [
     vue(),
+    {
+      // Simulates Vite's virtual files: https://vitejs.dev/guide/api-plugin.html#virtual-modules-convention
+      name: 'vitest-custom-virtual-files',
+      resolveId(id) {
+        if (id === 'virtual:vitest-custom-virtual-file')
+          return 'src/virtual:vitest-custom-virtual-file.ts'
+      },
+      load(id) {
+        if (id === 'src/virtual:vitest-custom-virtual-file.ts') {
+          return `
+            const virtualFile = "This file should be excluded from coverage report"
+            export default virtualFile;
+          `
+        }
+      },
+    },
   ],
   define: {
     MY_CONSTANT: '"my constant"',