fix(tooltip): hide tooltips when content becomes empty

Closes #875

src/tooltip/test/tooltip2.spec.js

@@ -0,0 +1,94 @@
+describe('tooltip directive', function () {
+
+  var $rootScope, $compile, $document, $timeout;
+
+  beforeEach(module('ui.bootstrap.tooltip'));
+  beforeEach(module('template/tooltip/tooltip-popup.html'));
+  beforeEach(inject(function (_$rootScope_, _$compile_, _$document_, _$timeout_) {
+    $rootScope = _$rootScope_;
+    $compile = _$compile_;
+    $document = _$document_;
+    $timeout = _$timeout_;
+  }));
+
+  beforeEach(function(){
+    this.addMatchers({
+      toHaveOpenTooltips: function(noOfOpened) {
+        var ttipElements = this.actual.find('div.tooltip');
+        noOfOpened = noOfOpened || 1;
+
+        this.message = function() {
+          return "Expected '" + angular.mock.dump(ttipElements) + "' to have '" + ttipElements.length + "' opened tooltips.";
+        };
+
+        return ttipElements.length === noOfOpened;
+      }
+    });
+  });
+
+  function compileTooltip(ttipMarkup) {
+    var fragment = $compile('<div>'+ttipMarkup+'</div>')($rootScope);
+    $rootScope.$digest();
+    return fragment;
+  }
+
+  function closeTooltip(hostEl, trigger, shouldNotFlush) {
+    hostEl.trigger(trigger || 'mouseleave' );
+    if (!shouldNotFlush) {
+      $timeout.flush();
+    }
+  }
+
+  describe('basic scenarios with default options', function () {
+
+    it('shows default tooltip on mouse enter and closes on mouse leave', function () {
+      var fragment = compileTooltip('<span tooltip="tooltip text">Trigger here</span>');
+
+      fragment.find('span').trigger( 'mouseenter' );
+      expect(fragment).toHaveOpenTooltips();
+
+      closeTooltip(fragment.find('span'));
+      expect(fragment).not.toHaveOpenTooltips();
+    });
+
+    it('should not show a tooltip when its content is empty', function () {
+      var fragment = compileTooltip('<span tooltip=""></span>');
+      fragment.find('span').trigger( 'mouseenter' );
+      expect(fragment).not.toHaveOpenTooltips();
+    });
+
+    it('should not show a tooltip when its content becomes empty', function () {
+
+      $rootScope.content = 'some text';
+      var fragment = compileTooltip('<span tooltip="{{ content }}"></span>');
+
+      fragment.find('span').trigger( 'mouseenter' );
+      expect(fragment).toHaveOpenTooltips();
+
+      $rootScope.content = '';
+      $rootScope.$digest();
+      $timeout.flush();
+      expect(fragment).not.toHaveOpenTooltips();
+    });
+  });
+
+  describe('option by option', function () {
+
+    describe('placement', function () {
+
+      it('can specify an alternative, valid placement', function () {
+        var fragment = compileTooltip('<span tooltip="tooltip text" tooltip-placement="left">Trigger here</span>');
+        fragment.find('span').trigger( 'mouseenter' );
+
+        var ttipElement = fragment.find('div.tooltip');
+        expect(fragment).toHaveOpenTooltips();
+        expect(ttipElement).toHaveClass('left');
+
+        closeTooltip(fragment.find('span'));
+        expect(fragment).not.toHaveOpenTooltips();
+      });
+
+    });
+
+  });
+});

src/tooltip/tooltip.js

@@ -242,7 +242,13 @@ angular.module( 'ui.bootstrap.tooltip', [ 'ui.bootstrap.position', 'ui.bootstrap
            * Observe the relevant attributes.
            */
           attrs.$observe( type, function ( val ) {
-            scope.tt_content = val;
+            if (val) {
+              scope.tt_content = val;
+            } else {
+              if ( scope.tt_isOpen ) {
+                hide();
+              }
+            }
           });
 
           attrs.$observe( prefix+'Title', function ( val ) {