From 8aacdafd4f9e49275c4f513d4e34d69f565ed9fc Mon Sep 17 00:00:00 2001
From: AriPerkkio <ari.perkkio@gmail.com>
Date: Fri, 21 Apr 2023 16:43:31 +0300
Subject: [PATCH] fix(coverage): workspaces c8 source maps

---
 packages/coverage-c8/src/provider.ts          |  6 ++-
 pnpm-lock.yaml                                |  6 +++
 .../check-coverage.test.ts                    | 46 +++++++++++++++++++
 .../coverage-report-tests/vitest.config.ts    |  7 +++
 test/workspaces/package.json                  |  7 ++-
 test/workspaces/src/math.ts                   | 11 +++++
 test/workspaces/vitest.config.ts              |  1 +
 7 files changed, 81 insertions(+), 3 deletions(-)
 create mode 100644 test/workspaces/coverage-report-tests/check-coverage.test.ts
 create mode 100644 test/workspaces/coverage-report-tests/vitest.config.ts

diff --git a/packages/coverage-c8/src/provider.ts b/packages/coverage-c8/src/provider.ts
index d37e446610876..e47ad12277e06 100644
--- a/packages/coverage-c8/src/provider.ts
+++ b/packages/coverage-c8/src/provider.ts
@@ -95,8 +95,12 @@ export class C8CoverageProvider extends BaseCoverageProvider implements Coverage
     const sourceMapMeta: Record<SourceMapMeta['url'], MapAndSource> = {}
     const extensions = Array.isArray(this.options.extension) ? this.options.extension : [this.options.extension]
 
+    const fetchCache = this.ctx.projects.map(project =>
+      Array.from(project.vitenode.fetchCache.entries()),
+    ).flat()
+
     const entries = Array
-      .from(this.ctx.vitenode.fetchCache.entries())
+      .from(fetchCache)
       .filter(entry => report._shouldInstrument(entry[0]))
       .map(([file, { result }]) => {
         if (!result.map)
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index b9af1ed3e0007..7da5ad7ad3518 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -1768,6 +1768,12 @@ importers:
 
   test/workspaces:
     devDependencies:
+      '@types/istanbul-lib-coverage':
+        specifier: ^2.0.4
+        version: 2.0.4
+      istanbul-lib-coverage:
+        specifier: ^3.2.0
+        version: 3.2.0
       jsdom:
         specifier: latest
         version: 21.1.1
diff --git a/test/workspaces/coverage-report-tests/check-coverage.test.ts b/test/workspaces/coverage-report-tests/check-coverage.test.ts
new file mode 100644
index 0000000000000..f84df1cbdb927
--- /dev/null
+++ b/test/workspaces/coverage-report-tests/check-coverage.test.ts
@@ -0,0 +1,46 @@
+import { existsSync, readFileSync } from 'node:fs'
+import { normalize } from 'node:path'
+import { expect, test } from 'vitest'
+import libCoverage from 'istanbul-lib-coverage'
+import { resolve } from 'pathe'
+
+test('coverage exists', () => {
+  expect(existsSync('./coverage')).toBe(true)
+  expect(existsSync('./coverage/index.html')).toBe(true)
+})
+
+test('file coverage summary matches', () => {
+  const coverageJson = JSON.parse(readFileSync('./coverage/coverage-final.json', 'utf-8'))
+  const coverageMap = libCoverage.createCoverageMap(coverageJson)
+  const fileCoverage = coverageMap.fileCoverageFor(normalize(resolve('./src/math.ts')))
+
+  // There should be 1 uncovered branch and 1 uncovered function. See math.ts.
+  expect(fileCoverage.toSummary()).toMatchInlineSnapshot(`
+    {
+      "branches": {
+        "covered": 3,
+        "pct": 75,
+        "skipped": 0,
+        "total": 4,
+      },
+      "functions": {
+        "covered": 2,
+        "pct": 66.66,
+        "skipped": 0,
+        "total": 3,
+      },
+      "lines": {
+        "covered": 7,
+        "pct": 50,
+        "skipped": 0,
+        "total": 14,
+      },
+      "statements": {
+        "covered": 7,
+        "pct": 50,
+        "skipped": 0,
+        "total": 14,
+      },
+    }
+  `)
+})
diff --git a/test/workspaces/coverage-report-tests/vitest.config.ts b/test/workspaces/coverage-report-tests/vitest.config.ts
new file mode 100644
index 0000000000000..18bb8372ffc45
--- /dev/null
+++ b/test/workspaces/coverage-report-tests/vitest.config.ts
@@ -0,0 +1,7 @@
+import { defineConfig } from 'vitest/config'
+
+export default defineConfig({
+  test: {
+    include: ['./check-coverage.test.ts'],
+  },
+})
diff --git a/test/workspaces/package.json b/test/workspaces/package.json
index 0b411b9d61268..10bc7a91f8bff 100644
--- a/test/workspaces/package.json
+++ b/test/workspaces/package.json
@@ -3,10 +3,13 @@
   "type": "module",
   "private": true,
   "scripts": {
-    "test": "vitest",
-    "coverage": "vitest run --coverage"
+    "test": "pnpm test:workspace && pnpm test:coverage",
+    "test:workspace": "vitest run",
+    "test:coverage": "vitest run --root coverage-report-tests"
   },
   "devDependencies": {
+    "@types/istanbul-lib-coverage": "^2.0.4",
+    "istanbul-lib-coverage": "^3.2.0",
     "jsdom": "latest",
     "vitest": "workspace:*"
   }
diff --git a/test/workspaces/src/math.ts b/test/workspaces/src/math.ts
index 5d8550bb9d4d8..f1e1874089f6e 100644
--- a/test/workspaces/src/math.ts
+++ b/test/workspaces/src/math.ts
@@ -1,3 +1,14 @@
+/* eslint-disable unused-imports/no-unused-vars */
 export function sum(a: number, b: number) {
+  if (a === 3 && b === 4) {
+    // This should be uncovered
+    return 7
+  }
+
   return a + b
 }
+
+function uncoveredFunction() {
+  // This should be uncovered
+  return 1
+}
diff --git a/test/workspaces/vitest.config.ts b/test/workspaces/vitest.config.ts
index 977555a2c4782..a817e50b78f3c 100644
--- a/test/workspaces/vitest.config.ts
+++ b/test/workspaces/vitest.config.ts
@@ -9,6 +9,7 @@ if (process.env.TEST_WATCH) {
 export default defineConfig({
   test: {
     coverage: {
+      enabled: true,
       all: true,
     },
     reporters: ['default', 'json'],