feat(theming): add warnings when using unregistered themes

src/core/services/theming/theming.js

@@ -282,7 +282,7 @@ function ThemingProvider($mdColorPalette) {
    * @param {el=} element to apply theming to
    */
   /* @ngInject */
-  function ThemingService($rootScope) {
+  function ThemingService($rootScope, $log) {
     applyTheme.inherit = function(el, parent) {
       var ctrl = parent.controller('mdTheme');
 
@@ -298,15 +298,26 @@ function ThemingProvider($mdColorPalette) {
       }
 
       function changeTheme(theme) {
+        if (!registered(name)) {
+          debugger;
+          $log.warn('attempted to use unregistered theme \'' + theme + '\'');
+        }
         var oldTheme = el.data('$mdThemeName');
         if (oldTheme) el.removeClass('md-' + oldTheme +'-theme');
         el.addClass('md-' + theme + '-theme');
         el.data('$mdThemeName', theme);
       }
     };
 
+    applyTheme.registered = registered;
+
     return applyTheme;
 
+    function registered(theme) {
+      if (theme === undefined || theme === '') return true;
+      return THEMES[theme] !== undefined;
+    }
+
     function applyTheme(scope, el) {
       // Allow us to be invoked via a linking function signature.
       if (el === undefined) {
@@ -321,13 +332,16 @@ function ThemingProvider($mdColorPalette) {
   }
 }
 
-function ThemingDirective($interpolate) {
+function ThemingDirective($mdTheming, $interpolate, $log) {
   return {
     priority: 100,
     link: {
       pre: function(scope, el, attrs) {
         var ctrl = {
           $setTheme: function(theme) {
+            if (!$mdTheming.registered(theme)) {
+              $log.warn('attempted to use unregistered theme \'' + theme + '\'');
+            }
             ctrl.$mdTheme = theme;
           }
         };

src/core/services/theming/theming.spec.js

@@ -35,6 +35,7 @@ describe('$mdThemingProvider', function() {
         .backgroundPalette('testPalette');
 
       testTheme = themingProvider.theme('test');
+
     });
     startAngular();
   }
@@ -361,6 +362,15 @@ describe('md-theme directive', function() {
     $rootScope.$apply('themey = "blue"');
     expect(ctrl.$mdTheme).toBe('blue');
   }));
+
+  it('warns when an unregistered theme is used', function() {
+    inject(function($log, $compile, $rootScope) {
+      spyOn($log, 'warn');
+      var el = $compile('<div md-theme="unregistered"></div>')($rootScope);
+      $rootScope.$apply();
+      expect($log.warn).toHaveBeenCalled();
+    });
+  });
 });
 
 describe('md-themable directive', function() {