[fix] win32 mismatch of path casings causes duplicate entries

lib/path-set.js

@@ -0,0 +1,25 @@
+/**
+ * A unique set of paths. Case insensitive on win32
+ */
+class PathSet extends Set {
+  constructor () {
+    super()
+    this._win32 = process.platform === 'win32'
+  }
+
+  add (value) {
+    if (this._win32) {
+      value = value.toLowerCase()
+    }
+    super.add(value)
+  }
+
+  has (value) {
+    if (this._win32) {
+      value = value.toLowerCase()
+    }
+    return super.has(value)
+  }
+}
+
+module.exports = PathSet

lib/report.js

@@ -3,6 +3,7 @@ const furi = require('furi')
 const libCoverage = require('istanbul-lib-coverage')
 const libReport = require('istanbul-lib-report')
 const reports = require('istanbul-reports')
+const PathSet = require('./path-set')
 const { readdirSync, readFileSync, statSync } = require('fs')
 const { isAbsolute, resolve, extname } = require('path')
 const getSourceMapFromFile = require('./source-map-from-file')
@@ -144,7 +145,7 @@ class Report {
   _getMergedProcessCov () {
     const { mergeProcessCovs } = require('@bcoe/v8-coverage')
     const v8ProcessCovs = []
-    const fileIndex = new Set() // Set<string>
+    const fileIndex = new PathSet() // PathSet<string>
     for (const v8ProcessCov of this._loadReports()) {
       if (this._isCoverageObject(v8ProcessCov)) {
         if (v8ProcessCov['source-map-cache']) {
@@ -217,7 +218,7 @@ class Report {
           'utf8'
         ))
       } catch (err) {
-        console.warn(`${err.stack}`)
+        console.warn(`Failed to parse tmp file: ${f} with: ${err.stack}`)
       }
     })
   }

test/fixtures/all/mock-v8-output/bad-casing.json

@@ -0,0 +1,74 @@
+{
+  "result": [
+    {
+      "scriptId": "51",
+      "url": "file:///TEST_CWD/test/fixtures/all/vanilla/MAIN.js",
+      "functions": [
+        {
+          "functionName": "",
+          "ranges": [
+            {
+              "startOffset": 0,
+              "endOffset": 111,
+              "count": 1
+            }
+          ],
+          "isBlockCoverage": true
+        }
+      ]
+    },
+    {
+      "scriptId": "52",
+      "url": "file:///TEST_CWD/test/fixtures/all/vanilla/LOADED.js",
+      "functions": [
+        {
+          "functionName": "",
+          "ranges": [
+            {
+              "startOffset": 0,
+              "endOffset": 309,
+              "count": 1
+            }
+          ],
+          "isBlockCoverage": true
+        },
+        {
+          "functionName": "getString",
+          "ranges": [
+            {
+              "startOffset": 17,
+              "endOffset": 309,
+              "count": 3
+            },
+            {
+              "startOffset": 89,
+              "endOffset": 117,
+              "count": 0
+            },
+            {
+              "startOffset": 140,
+              "endOffset": 169,
+              "count": 1
+            },
+            {
+              "startOffset": 169,
+              "endOffset": 267,
+              "count": 2
+            },
+            {
+              "startOffset": 190,
+              "endOffset": 267,
+              "count": 1
+            },
+            {
+              "startOffset": 272,
+              "endOffset": 306,
+              "count": 0
+            }
+          ],
+          "isBlockCoverage": true
+        }
+      ]
+    }
+    ]
+}

test/integration.js

@@ -1,7 +1,15 @@
 /* global describe, before, beforeEach, it */
 
 const { spawnSync } = require('child_process')
-const { statSync } = require('fs')
+
+const {
+  statSync,
+  readFileSync,
+  writeFileSync,
+  existsSync,
+  mkdirSync
+} = require('fs')
+
 const c8Path = require.resolve('../bin/c8')
 const nodePath = process.execPath
 const tsNodePath = './node_modules/.bin/ts-node'
@@ -415,5 +423,39 @@ describe('c8', () => {
       ])
       output.toString('utf8').should.matchSnapshot()
     })
+
+    if (process.platform === 'win32') {
+      // issue: https://github.com/bcoe/c8/issues/191
+      it('should, given path casing mismatches between path.resolve and v8 output, NOT contain duplicate report entries', async () => {
+        // make a fake v8 blob using a template from fixtures that
+        // purposely contains case mismatches with nodes path.resolve on windows
+        const cwd = process.cwd()
+        const mockOutput = readFileSync('./test/fixtures/all/mock-v8-output/bad-casing.json')
+          .toString('utf8')
+          .replace(/TEST_CWD/g, process.cwd().replace(/\\/g, '/'))
+        const tmpDir = `${cwd}/tmp/mockcwd/`
+        if (!existsSync(tmpDir)) {
+          mkdirSync(tmpDir, { recursive: true })
+        }
+        writeFileSync(`${tmpDir}/v8.json`, mockOutput, 'utf-8')
+
+        // run c8
+        const { output } = spawnSync(nodePath, [
+          c8Path,
+          'report',
+          `--temp-directory=${tmpDir}`,
+          '--clean=true',
+          '--all=true',
+          '--include=test/fixtures/all/vanilla/**/*.js',
+          '--exclude=**/*.ts', // add an exclude to avoid default excludes of test/**
+          nodePath,
+          require.resolve('./fixtures/all/vanilla/main')
+        ])
+
+        // prior to issue 191 all would provide an extra 0 coverage record
+        // for each mismatched file
+        output.toString('utf8').should.matchSnapshot()
+      })
+    }
   })
 })

test/integration.js.snap

@@ -88,6 +88,20 @@ exports[`c8 --all should allow for --all to be used with the check-coverage comm
 "
 `;
 
+exports[`c8 --all should, given path casing mismatches between path.resolve and v8 output, NOT contain duplicate report entries 1`] = `
+",--------------|---------|----------|---------|---------|-------------------
+File          | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s 
+--------------|---------|----------|---------|---------|-------------------
+All files     |   64.29 |    66.67 |      50 |   64.29 |                   
+ vanilla      |   78.26 |       75 |     100 |   78.26 |                   
+  LOADED.js   |   73.68 |    71.43 |     100 |   73.68 | 4,5,16-18         
+  MAIN.js     |     100 |      100 |     100 |     100 |                   
+ vanilla/dir  |       0 |        0 |       0 |       0 |                   
+  unloaded.js |       0 |        0 |       0 |       0 | 1-5               
+--------------|---------|----------|---------|---------|-------------------
+,"
+`;
+
 exports[`c8 ESM Modules collects coverage for ESM modules 1`] = `
 ",bar foo
 ------------|---------|----------|---------|---------|-------------------

test/path-set.js

@@ -0,0 +1,38 @@
+/* global describe, it */
+const PathSet = require('../lib/path-set')
+const assert = require('assert')
+describe('path-set', () => {
+  it('should have only one entry when adding strings with different cases on win32', () => {
+    const pathSet = new PathSet()
+    pathSet._win32 = true
+    const file = 'foo.js'
+    pathSet.add(file)
+    pathSet.add(file.toUpperCase())
+    assert.strictEqual(pathSet.size, 1)
+  })
+
+  it('should have multiple entries when adding strings with different cases on non-win32', () => {
+    const pathSet = new PathSet()
+    pathSet._win32 = false
+    const file = 'foo.js'
+    pathSet.add(file)
+    pathSet.add(file.toUpperCase())
+    assert.strictEqual(pathSet.size, 2)
+  })
+
+  it('has should return true for different cases on win32', () => {
+    const pathSet = new PathSet()
+    pathSet._win32 = true
+    const file = 'foo.js'
+    pathSet.add(file)
+    assert(pathSet.has(file.toUpperCase()))
+  })
+
+  it('has should NOT return true for different cases non-win32', () => {
+    const pathSet = new PathSet()
+    pathSet._win32 = false
+    const file = 'foo.js'
+    pathSet.add(file)
+    assert(!pathSet.has(file.toUpperCase()))
+  })
+})