Add setDeviceId

Author: curtisliu

amplitude.js

@@ -283,6 +283,17 @@ Amplitude.prototype.setUserId = function(userId) {
   }
 };
 
+Amplitude.prototype.setDeviceId = function(deviceId) {
+  try {
+    if (deviceId) {
+      this.options.deviceId = ('' + deviceId);
+      _saveCookieData(this);
+    }
+  } catch (e) {
+    log(e);
+  }
+};
+
 Amplitude.prototype.setUserProperties = function(userProperties, opt_replace) {
   try {
     if (opt_replace) {

amplitude.min.js

@@ -12,7 +12,8 @@
       amplitude._q.push([fn].concat(Array.prototype.slice.call(arguments, 0)));
     };
   }
-  var funcs = ["init", "logEvent", "setUserId", "setUserProperties", "setVersionName", "setDomain", "setGlobalUserProperties"];
+  var funcs = ["init", "logEvent", "setUserId", "setUserProperties", "setVersionName", "setDomain", "setDeviceId",
+      "setGlobalUserProperties"];
   for (var i = 0; i < funcs.length; i++) {
     proxy(funcs[i]);
   }

src/amplitude-snippet.js

@@ -173,6 +173,17 @@ Amplitude.prototype.setUserId = function(userId) {
   }
 };
 
+Amplitude.prototype.setDeviceId = function(deviceId) {
+  try {
+    if (deviceId) {
+      this.options.deviceId = ('' + deviceId);
+      _saveCookieData(this);
+    }
+  } catch (e) {
+    log(e);
+  }
+};
+
 Amplitude.prototype.setUserProperties = function(userProperties, opt_replace) {
   try {
     if (opt_replace) {

src/amplitude.js

@@ -86,6 +86,37 @@ describe('Amplitude', function() {
     });
   });
 
+  describe('setDeviceId', function() {
+
+    afterEach(function() {
+      reset();
+    });
+
+    it('should change device id', function() {
+      amplitude.setDeviceId('deviceId');
+      amplitude.init(apiKey);
+      assert.equal(amplitude.options.deviceId, 'deviceId');
+    });
+
+    it('should not change device id if empty', function() {
+      amplitude.setDeviceId('');
+      amplitude.init(apiKey);
+      assert.notEqual(amplitude.options.deviceId, '');
+    });
+
+    it('should not change device id if null', function() {
+      amplitude.setDeviceId(null);
+      amplitude.init(apiKey);
+      assert.notEqual(amplitude.options.deviceId, null);
+    });
+
+    it('should store device id in cookie', function() {
+      amplitude.setDeviceId('deviceId');
+      var stored = cookie.get(amplitude.options.cookieName);
+      assert.propertyVal(stored, 'deviceId', 'deviceId');
+    });
+  });
+
   describe('logEvent', function() {
 
     beforeEach(function() {