fix(tagsInput): Remove duplicate tags on paste

Closes #795.

Author: stehlikio

src/tags-input.js

@@ -448,7 +448,12 @@ export default function TagsInputDirective($timeout, $document, $window, $q, tag
         .on('input-paste', event => {
           if (options.addOnPaste) {
             let data = event.getTextData();
-            let tags = data.split(options.pasteSplitPattern);
+
+            let tags = data
+              .split(options.pasteSplitPattern)
+              .filter((element, index, array) =>
+                  array.indexOf(element, index + 1) === -1
+              );
 
             if (tags.length > 1) {
               tags.forEach(tag => {

test/tags-input.spec.js

@@ -723,6 +723,24 @@ describe('tags-input directive', () => {
           expect(eventData.preventDefault).toHaveBeenCalled();
         });
 
+        it('removes duplicate tags from split text (' + name + ')', () => {
+          // Arrange
+          compile('add-on-paste="true"');
+          setup('tag1, tag2, tag2, tag3');
+
+          // Act
+          let event = jQuery.Event('paste', eventData);
+          getInput().trigger(event);
+
+          // Assert
+          expect($scope.tags).toEqual([
+            { text: 'tag1' },
+            { text: 'tag2' },
+            { text: 'tag3' }
+          ]);
+          expect(eventData.preventDefault).toHaveBeenCalled();
+        });
+
         it('doesn\'t split the pasted text into tags if there is just one tag (' + name + ')', () => {
           // Arrange
           compile('add-on-paste="true"');