From 605cecf92bf080cfbb891c3fdf30b7b11b889b6e Mon Sep 17 00:00:00 2001
From: Doug Luce <doug@github.con.com>
Date: Fri, 8 Jul 2016 13:24:53 -0700
Subject: [PATCH] Add code coverage stats

Electron-mocha makes things like this a little difficult.  Luckily,
@inukshuk in
https://github.com/jprichardson/electron-mocha/issues/19#issuecomment-227868475
figures out a way to get around it. It's a bit of effort but does work
in the end.

With any luck an npm module will come out with these clues embedded in
it and the coverage.js can be removed.
---
 .gitignore       |  1 +
 package.json     |  5 ++++-
 test/coverage.js | 57 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 62 insertions(+), 1 deletion(-)
 create mode 100644 test/coverage.js

diff --git a/.gitignore b/.gitignore
index c2658d7..25fbf5a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 node_modules/
+coverage/
diff --git a/package.json b/package.json
index 6b5654e..1593645 100644
--- a/package.json
+++ b/package.json
@@ -5,7 +5,8 @@
   "main": "index.js",
   "scripts": {
     "test": "electron-mocha",
-    "testmon": "nodemon --exec '(electron-mocha && growlnotify -n nodemon --image ~/green.png -m good) || (growlnotify -n nodemon --image ~/red.png -m crash && exit 1)'"
+    "testmon": "nodemon --exec '(electron-mocha && growlnotify -n nodemon --image ~/green.png -m good) || (growlnotify -n nodemon --image ~/red.png -m crash && exit 1)'",
+    "coverage": "electron-mocha --require test/coverage && istanbul report lcov"
   },
   "bin": {
     "scan": "./bin/scan"
@@ -14,8 +15,10 @@
   "license": "ISC",
   "devDependencies": {
     "chai": "^3.5.0",
+    "coveralls": "^2.11.9",
     "electron-mocha": "^2.3.0",
     "express": "^4.14.0",
+    "istanbul": "^0.4.4",
     "mocha": "^2.5.3",
     "nodemon": "^1.9.2"
   },
diff --git a/test/coverage.js b/test/coverage.js
new file mode 100644
index 0000000..b267f4e
--- /dev/null
+++ b/test/coverage.js
@@ -0,0 +1,57 @@
+'use strict'
+
+// Largely cribbed from
+// https://raw.githubusercontent.com/tropy/tropy/master/test/support/coverage.js
+
+const glob = require('glob')
+const { readFileSync: read, realpathSync } = require('fs')
+const { Reporter, Instrumenter, Collector, hook } = require('istanbul')
+const { keys } = Object
+
+function match () {
+  const map = {}
+  const fn = function (file) { return map[file] }
+  fn.files = []
+
+  for (let file of glob.sync(pattern)) {
+    let fullpath = realpathSync(file)
+    fn.files.push(fullpath)
+    map[fullpath] = true
+  }
+
+  return fn
+}
+
+function report () {
+  const cov = global.__coverage__
+  for (let file of matched.files) {
+    if (!cov[file]) {
+      // Add uncovered files to the report.
+      transformer(read(file, 'utf-8'), file)
+      for (let key of keys(instrumenter.coverState.s)) {
+        instrumenter.coverState.s[key] = 0
+      }
+      cov[file] = instrumenter.coverState
+    }
+  }
+
+  const collector = new Collector()
+  collector.add(cov)
+
+  const reporter = new Reporter()
+  reporter.addAll(['text-summary', 'json'])
+  reporter.write(collector, true, () => {})
+}
+
+// The source files to cover.  Avoid node_modules/, coverage/, and
+// */coverage.js (supposed to be test/coverage.js)
+
+const pattern = '{!(node_modules|coverage)/**,.}/!(coverage).js'
+const matched = match()
+
+const instrumenter = new Instrumenter()
+const transformer = instrumenter.instrumentSync.bind(instrumenter)
+
+hook.hookRequire(matched, transformer, {})
+
+process.on('exit', report)