Make DriveScanner.start() return an EventEmitter instance

build/browser/app.js

@@ -117,6 +117,7 @@ app.controller('AppController', function($q, DriveScannerService, SelectionState
 
 var angular = require('angular');
 var _ = require('lodash');
+var EventEmitter = require('events').EventEmitter;
 var remote = window.require('remote');
 
 if (window.mocha) {
@@ -247,15 +248,32 @@ driveScanner.service('DriveScannerService', function($q, DriveScannerRefreshServ
    * @function
    * @public
    *
+   * @description
+   * This function returns an event emitter instance
+   * that emits a `scan` event everything it scans
+   * the drives successfully.
+   *
    * @param {Number} ms - interval milliseconds
+   * @returns {EventEmitter} event emitter instance
    *
    * @example
-   * DriveScannerService.start(2000);
+   * var emitter = DriveScannerService.start(2000);
+   *
+   * emitter.on('scan', function(drives) {
+   *   console.log(drives);
+   * });
    */
   this.start = function(ms) {
+    var emitter = new EventEmitter();
+
     DriveScannerRefreshService.every(function() {
-      return self.scan().then(self.setDrives);
+      return self.scan().then(function(drives) {
+        emitter.emit('scan', drives);
+        self.setDrives(drives);
+      });
     }, ms);
+
+    return emitter;
   };
 
   /**

lib/browser/modules/drive-scanner.js

@@ -20,6 +20,7 @@
 
 var angular = require('angular');
 var _ = require('lodash');
+var EventEmitter = require('events').EventEmitter;
 var remote = window.require('remote');
 
 if (window.mocha) {
@@ -150,15 +151,32 @@ driveScanner.service('DriveScannerService', function($q, DriveScannerRefreshServ
    * @function
    * @public
    *
+   * @description
+   * This function returns an event emitter instance
+   * that emits a `scan` event everything it scans
+   * the drives successfully.
+   *
    * @param {Number} ms - interval milliseconds
+   * @returns {EventEmitter} event emitter instance
    *
    * @example
-   * DriveScannerService.start(2000);
+   * var emitter = DriveScannerService.start(2000);
+   *
+   * emitter.on('scan', function(drives) {
+   *   console.log(drives);
+   * });
    */
   this.start = function(ms) {
+    var emitter = new EventEmitter();
+
     DriveScannerRefreshService.every(function() {
-      return self.scan().then(self.setDrives);
+      return self.scan().then(function(drives) {
+        emitter.emit('scan', drives);
+        self.setDrives(drives);
+      });
     }, ms);
+
+    return emitter;
   };
 
   /**

tests/browser/modules/drive-scanner.spec.js

@@ -181,6 +181,21 @@ describe('Browser: DriveScanner', function() {
         DriveScannerService.stop();
       });
 
+      describe('.start()', function() {
+
+        it('should emit a `scan` event with the drives', function() {
+          var emitter = DriveScannerService.start(2000);
+          var scanSpy = m.sinon.spy();
+          emitter.on('scan', scanSpy);
+          $timeout.flush();
+          $interval.flush(1000);
+          m.chai.expect(scanSpy).to.have.been.calledOnce;
+          m.chai.expect(scanSpy).to.have.been.calledWith(this.drives);
+          DriveScannerService.stop();
+        });
+
+      });
+
     });
 
   });