Add helper to instrument electron.asar

spec/static/coverage.js

@@ -1,12 +1,16 @@
+const asar = require('asar')
 const fs = require('fs')
 const glob = require('glob')
+const mkdirp = require('mkdirp')
 const path = require('path')
-const {ipcRenderer} = require('electron')
 const {Collector, Instrumenter, Reporter} = require('istanbul')
 
+const outputPath = path.join(__dirname, '..', '..', 'out', 'coverage')
+const libPath = path.join(__dirname, '..', '..', 'lib')
+
+// Add unrequired files to the coverage report so all files are present there
 const addUnrequiredFiles = (coverage) => {
   const instrumenter = new Instrumenter()
-  const transformer = instrumenter.instrumentSync.bind(instrumenter)
   const libPath = path.join(__dirname, '..', '..', 'lib')
 
   glob.sync('**/*.js', {cwd: libPath}).map(function (relativePath) {
@@ -14,7 +18,7 @@ const addUnrequiredFiles = (coverage) => {
   }).filter(function (filePath) {
     return coverage[filePath] == null
   }).forEach(function (filePath) {
-    transformer(fs.readFileSync(filePath, 'utf8'), filePath)
+    instrumenter.instrumentSync(fs.readFileSync(filePath, 'utf8'), filePath)
 
     // When instrumenting the code, istanbul will give each FunctionDeclaration
     // a value of 1 in coverState.s,presumably to compensate for function
@@ -28,6 +32,7 @@ const addUnrequiredFiles = (coverage) => {
   })
 }
 
+// Generate a code coverage report in out/coverage/lcov-report
 exports.generate = () => {
   const coverage = window.__coverage__
   if (coverage == null) return
@@ -36,10 +41,35 @@ exports.generate = () => {
 
   const collector = new Collector()
   collector.add(coverage)
+
+  const {ipcRenderer} = require('electron')
   collector.add(ipcRenderer.sendSync('get-coverage'))
 
-  const outPath = path.join(__dirname, '..', '..', 'out', 'coverage')
+  const reporter = new Reporter(null, outputPath)
-  const reporter = new Reporter(null, outPath)
   reporter.addAll(['text', 'lcov'])
   reporter.write(collector, true, function () {})
 }
+
+// Generate an instrumented .asar file for all the files in lib/ and save it
+// to out/coverage/electron-instrumented.asar
+exports.instrument = () => {
+  const instrumenter = new Instrumenter()
+
+  glob.sync('**/*.js', {cwd: libPath}).forEach(function (relativePath) {
+    const rawPath = path.join(libPath, relativePath)
+    const raw = fs.readFileSync(rawPath, 'utf8')
+
+    const generatedPath = path.join(outputPath, 'lib', relativePath)
+    const generated = instrumenter.instrumentSync(raw, rawPath)
+    mkdirp.sync(path.dirname(generatedPath))
+    fs.writeFileSync(generatedPath, generated)
+  })
+
+  const asarPath = path.join(outputPath, 'electron-instrumented.asar')
+  asar.createPackageWithOptions(path.join(outputPath, 'lib'), asarPath, {}, function (error) {
+    if (error) {
+      console.error(error.stack || error)
+      process.exit(1)
+    }
+  })
+}