fix(sourcemap): add head.js sourcemap

Fixes mozilla/fxa-content-server#3355

packages/fxa-content-server/grunttasks/build.js

@@ -57,8 +57,10 @@ module.exports = function (grunt) {
     // replaces the blocks by the file they reference,
     // and replaces all references to assets by their revisioned version if it is found on the disk
     'usemin',
-    // copy the non-minified scripts file for sourcemap purposes
+    // copy the non-minified main.js script file for sourcemap purposes
     'copy:build',
+    // copy the non-minified head.js script file for sourcemap purposes
+    'copy:head',
     // update the sourcemap path to match the hosted files
     'sourcemap-source',
 

packages/fxa-content-server/grunttasks/copy.js

@@ -69,6 +69,14 @@ module.exports = function (grunt) {
         src: 'en/{500,502,503}.html'
       }]
     },
+    head: {
+      files: [{
+        cwd: '<%= yeoman.tmp %>/concat/scripts',
+        dest: '<%= yeoman.dist %>/scripts',
+        expand: true,
+        src: ['**/*.js']
+      }]
+    },
     // copy normalize.css to .tmp during build, this library is required by grunt-usemin to be in .tmp
     normalize: {
       dest: '<%= yeoman.tmp %>/bower_components/normalize-css/normalize.css',

packages/fxa-content-server/grunttasks/sourcemap-source.js

@@ -10,13 +10,19 @@ module.exports = function (grunt) {
    */
 
   var fs = require('fs');
-  var MAP_PATH = 'dist/scripts/main.js.map';
+
 
   grunt.registerTask('sourcemap-source', 'Adjusts the sourcemap source file to match the hosted path.', function () {
 
-    var existingMap = JSON.parse(fs.readFileSync(MAP_PATH));
+    var MAP_PATH_MAIN = 'dist/scripts/main.js.map';
+    var existingMap = JSON.parse(fs.readFileSync(MAP_PATH_MAIN));
     existingMap.sources = ['main.js'];
+    fs.writeFileSync(MAP_PATH_MAIN, JSON.stringify(existingMap));
+
+    var MAP_PATH_HEAD = 'dist/scripts/head.js.map';
+    var existingMapHead = JSON.parse(fs.readFileSync(MAP_PATH_HEAD));
+    existingMapHead.sources = ['head.js'];
+    fs.writeFileSync(MAP_PATH_HEAD, JSON.stringify(existingMapHead));
 
-    fs.writeFileSync(MAP_PATH, JSON.stringify(existingMap));
   });
 };