fix(highlight-flags): make ^/$ work properly

Fixes #8096

Closes #8120

Author: ivoviz

src/components/autocomplete/autocomplete.spec.js

@@ -1204,6 +1204,40 @@ describe('<md-autocomplete>', function() {
 
       element.remove();
     }));
+
+    it('should properly apply highlight flags', inject(function() {
+      var template = '<div md-highlight-text="query" md-highlight-flags="{{flags}}">{{message}}</div>';
+      var scope = createScope(null, {message: 'Some text', query: 'some', flags: '^i'});
+      var element = compile(template, scope);
+
+      expect(element.html()).toBe('<span class="highlight">Some</span> text');
+
+      scope.query = 'text';
+      scope.$apply();
+
+      expect(element.html()).toBe('Some text');
+
+      scope.message = 'Some text, some flags';
+      scope.query = 'some';
+      scope.flags = 'ig';
+      element = compile(template, scope);
+
+      expect(element.html()).toBe('<span class="highlight">Some</span> text, <span class="highlight">some</span> flags');
+
+      scope.query = 'some';
+      scope.flags = '^i';
+      element = compile(template, scope);
+
+      expect(element.html()).toBe('<span class="highlight">Some</span> text, some flags');
+
+      scope.query = 's';
+      scope.flags = '$i';
+      element = compile(template, scope);
+
+      expect(element.html()).toBe('Some text, some flag<span class="highlight">s</span>');
+
+      element.remove();
+    }));
   });
 
 });

src/components/autocomplete/js/highlightController.js

@@ -32,10 +32,9 @@ function MdHighlightCtrl ($scope, $element, $attrs) {
   }
 
   function getRegExp (text, flags) {
-    var str = '';
-    if (flags.indexOf('^') >= 1) str += '^';
-    str += text;
-    if (flags.indexOf('$') >= 1) str += '$';
-    return new RegExp(sanitize(str), flags.replace(/[\$\^]/g, ''));
+    var startFlag = '', endFlag = '';
+    if (flags.indexOf('^') >= 0) startFlag = '^';
+    if (flags.indexOf('$') >= 0) endFlag = '$';
+    return new RegExp(startFlag + sanitize(text) + endFlag, flags.replace(/[\$\^]/g, ''));
   }
 }