From fbf51979d8f6eddc465e7497492cd44937569b2e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ari=20Perkki=C3=B6?= <ari.perkkio@gmail.com>
Date: Thu, 18 Aug 2022 18:38:48 +0000
Subject: [PATCH] feat(coverage-istanbul): add "all" option - Similar as nyc
 and c8 has

---
 docs/config/index.md                          |  7 ++++
 packages/coverage-istanbul/src/provider.ts    | 40 ++++++++++++++++++-
 packages/vitest/src/types/coverage.ts         |  6 ++-
 .../coverage-test/coverage.istanbul.test.ts   |  9 ++++-
 test/coverage-test/src/untested-file.ts       |  3 ++
 test/coverage-test/vitest.config.ts           |  1 +
 6 files changed, 62 insertions(+), 4 deletions(-)
 create mode 100644 test/coverage-test/src/untested-file.ts

diff --git a/docs/config/index.md b/docs/config/index.md
index e10422b5c36b..478c5b5a68e5 100644
--- a/docs/config/index.md
+++ b/docs/config/index.md
@@ -518,6 +518,13 @@ Set to array of class method names to ignore for coverage.
 
 Watermarks for statements, lines, branches and functions.
 
+##### all
+
+- **Type:** `boolean`
+- **Default:** false
+
+Whether to include all files, including the untested ones into report.
+
 ### testNamePattern
 
 - **Type** `string | RegExp`
diff --git a/packages/coverage-istanbul/src/provider.ts b/packages/coverage-istanbul/src/provider.ts
index 82614cedd688..ad5d54037201 100644
--- a/packages/coverage-istanbul/src/provider.ts
+++ b/packages/coverage-istanbul/src/provider.ts
@@ -23,7 +23,10 @@ interface TestExclude {
     exclude?: string | string[]
     extension?: string | string[]
     excludeNodeModules?: boolean
-  }): { shouldInstrument(filePath: string): boolean }
+  }): {
+    shouldInstrument(filePath: string): boolean
+    glob(cwd: string): Promise<string[]>
+  }
 }
 
 export class IstanbulCoverageProvider implements CoverageProvider {
@@ -95,12 +98,15 @@ export class IstanbulCoverageProvider implements CoverageProvider {
   }
 
   async reportCoverage() {
-    const mergedCoverage = this.coverages.reduce((coverage, previousCoverageMap) => {
+    const mergedCoverage: CoverageMap = this.coverages.reduce((coverage, previousCoverageMap) => {
       const map = libCoverage.createCoverageMap(coverage)
       map.merge(previousCoverageMap)
       return map
     }, {})
 
+    if (this.options.all)
+      await this.includeUntestedFiles(mergedCoverage)
+
     const sourceMapStore = libSourceMaps.createSourceMapStore()
     const coverageMap: CoverageMap = await sourceMapStore.transformCoverage(mergedCoverage)
 
@@ -175,6 +181,36 @@ export class IstanbulCoverageProvider implements CoverageProvider {
       }
     }
   }
+
+  async includeUntestedFiles(coverageMap: CoverageMap) {
+    const files = await this.testExclude.glob(this.ctx.config.root)
+
+    for (const file of files) {
+      const filename = resolve(this.ctx.config.root, file)
+
+      // Load, instrument and collect empty coverages from all files which
+      // are not already in the coverage map
+      if (!coverageMap.data[filename]) {
+        const transformResult = await this.ctx.vitenode.transformRequest(filename)
+        const sourceMap = transformResult?.map
+
+        if (sourceMap) {
+          this.instrumenter.instrumentSync(
+            transformResult.code,
+            filename,
+            {
+              ...sourceMap,
+              version: sourceMap.version.toString(),
+            },
+          )
+
+          const lastCoverage = this.instrumenter.lastFileCoverage()
+          if (lastCoverage)
+            coverageMap.data[lastCoverage.path] = lastCoverage
+        }
+      }
+    }
+  }
 }
 
 function resolveIstanbulOptions(options: CoverageIstanbulOptions, root: string) {
diff --git a/packages/vitest/src/types/coverage.ts b/packages/vitest/src/types/coverage.ts
index d1adf01b48d2..f68fd07ed18f 100644
--- a/packages/vitest/src/types/coverage.ts
+++ b/packages/vitest/src/types/coverage.ts
@@ -137,6 +137,11 @@ export interface BaseCoverageOptions {
    * Extensions for files to be included in coverage
    */
   extension?: string | string[]
+
+  /**
+   * Whether to include all files, including the untested ones into report
+   */
+  all?: boolean
 }
 
 export interface CoverageIstanbulOptions extends BaseCoverageOptions {
@@ -166,7 +171,6 @@ export interface CoverageC8Options extends BaseCoverageOptions {
    */
   excludeNodeModules?: boolean
 
-  all?: boolean
   src?: string[]
 
   100?: boolean
diff --git a/test/coverage-test/coverage-test/coverage.istanbul.test.ts b/test/coverage-test/coverage-test/coverage.istanbul.test.ts
index c2188e16ec90..72dfddfbdcdc 100644
--- a/test/coverage-test/coverage-test/coverage.istanbul.test.ts
+++ b/test/coverage-test/coverage-test/coverage.istanbul.test.ts
@@ -3,7 +3,7 @@ import { resolve } from 'pathe'
 import { expect, test } from 'vitest'
 
 test('istanbul html report', async () => {
-  const coveragePath = resolve('./coverage')
+  const coveragePath = resolve('./coverage/coverage-test/src')
   const files = fs.readdirSync(coveragePath)
 
   expect(files).toContain('index.html')
@@ -22,3 +22,10 @@ test('istanbul lcov report', async () => {
 
   expect(lcovReportFiles).toContain('index.html')
 })
+
+test('all includes untested files', () => {
+  const coveragePath = resolve('./coverage/coverage-test/src')
+  const files = fs.readdirSync(coveragePath)
+
+  expect(files).toContain('untested-file.ts.html')
+})
diff --git a/test/coverage-test/src/untested-file.ts b/test/coverage-test/src/untested-file.ts
new file mode 100644
index 000000000000..1d1313eef8d4
--- /dev/null
+++ b/test/coverage-test/src/untested-file.ts
@@ -0,0 +1,3 @@
+export default function untestedFile() {
+  return 'This file should end up in report when {"all": true} is given'
+}
diff --git a/test/coverage-test/vitest.config.ts b/test/coverage-test/vitest.config.ts
index 3d4e9cf640f3..0570d7959b7b 100644
--- a/test/coverage-test/vitest.config.ts
+++ b/test/coverage-test/vitest.config.ts
@@ -19,6 +19,7 @@ export default defineConfig({
     coverage: {
       enabled: true,
       clean: true,
+      all: true,
       reporter: ['html', 'text', 'lcov'],
     },
   },