Integrate istanbul for test coverage

.gitignore

@@ -5,3 +5,5 @@
 /examples/example-list.xml
 /node_modules/
 /dist/
+/src_instrumented/
+/coverage/

.travis.yml

@@ -6,3 +6,5 @@ before_script:
   - "rm src/ol/renderer/webgl/*shader.js"
 
 script: "./build.py ci"
+
+after_success: "npm run test-coverage"

package.json

@@ -12,7 +12,8 @@
     "install": "node tasks/install.js",
     "postinstall": "closure-util update",
     "start": "node tasks/serve.js",
-    "test": "node tasks/test.js"
+    "test": "node tasks/test.js",
+    "test-coverage": "istanbul instrument src -o src_instrumented && mv src src_old && mv src_instrumented src && istanbul cover npm test istanbul && mv src src_instrumented && mv src_old src && istanbul report --root coverage lcov"
   },
   "main": "dist/ol.js",
   "repository": {
@@ -38,6 +39,7 @@
   "devDependencies": {
     "clean-css": "2.2.16",
     "expect.js": "0.3.1",
+    "istanbul": "^0.3.13",
     "jquery": "2.1.1",
     "jshint": "2.5.6",
     "mocha": "1.21.5",

tasks/test.js

@@ -60,6 +60,11 @@ serve.createServer(function(err, server) {
       url + '/test/index.html'
     ];
 
+    if (process.argv.length > 2 && process.argv[2] === 'istanbul') {
+      args.push('spec', '{"hooks": "' +
+          path.join(__dirname, '../test/phantom_hooks.js') + '"}');
+    }
+
     var child = spawn(phantomjs.path, args, {stdio: 'inherit'});
     child.on('exit', function(code) {
       process.exit(code);

test/phantom_hooks.js

@@ -0,0 +1,15 @@
+module.exports = {
+  afterEnd: function(runner) {
+    var fs = require('fs');
+    var coverage = runner.page.evaluate(function() {
+      return window.__coverage__;
+    });
+
+    if (coverage) {
+      console.log('Writing coverage to coverage/coverage.json');
+      fs.write('coverage/coverage.json', JSON.stringify(coverage), 'w');
+    } else {
+      console.log('No coverage data generated');
+    }
+  }
+};