Merge pull request #297 from syedfaizan/master

added unique helper

Author: jonschlinkert

README.md

@@ -138,6 +138,7 @@ Visit the: [code](lib/array.js) | [unit tests](test/array.js) | [issues](https:/
 * **[withGroup](#withGroup)** ([code](lib/array.js#L692) | [tests](test/array.js#L418))
 * **[withLast](#withLast)** ([code](lib/array.js#L727) | [tests](test/array.js#L428))
 * **[withSort](#withSort)** ([code](lib/array.js#L766) | [tests](test/array.js#L442))
+* **[unique](#unique)** ([code](lib/array.js#L801) | [tests](test/array.js#L483))
 
 ### [code helpers](#code)
 
@@ -927,6 +928,25 @@ Block helper that sorts a collection and exposes the sorted collection as contex
 
 ## code
 
+### [{{unique}}](lib/array.js#L801)
+
+Block helper that return an array with all duplicate values removed. Best used along with a #each helper
+
+**Params**
+
+* `array` **{Array}**
+* `returns` **{Array}**: Array with No duplicate values
+
+**Example**
+
+```handlebars
+<!-- array: ['a', 'a', 'c', 'b', 'e', 'e'] -->
+{{#each (unique array)}}{{this}}{{/each}}
+<!-- results in: 'acbe' -->
+```
+
+## code
+
 ### [{{embed}}](lib/code.js#L24)
 
 Embed code from an external file as preformatted text.

lib/array.js

@@ -797,3 +797,13 @@ helpers.withSort = function(array, prop, options) {
   }
   return result;
 };
+
+helpers.unique = function(array, options) {
+  if (util.isUndefined(array)) return '';
+
+  return array.filter(function(item, index, self) {
+    return self.indexOf(item) === index;
+  });
+  
+};
+

test/array.js

@@ -7,7 +7,7 @@ var helpers = require('..');
 helpers.array({handlebars: hbs});
 helpers.string({handlebars: hbs});
 
-var context = {array: ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h']};
+var context = {array: ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'], duplicate: [ 'a', 'b', 'b', 'c', 'd', 'b', 'f', 'a', 'g']};
 
 describe('array', function() {
   describe('after', function() {
@@ -479,4 +479,16 @@ describe('array', function() {
       assert.equal(res, 'f: 8021 <br>b: 239 <br>d: -12 <br>');
     });
   });
+
+  describe('unique', function() {
+    it('should return empty string when the array is null', function() {
+      var fn = hbs.compile('{{#unique}}{{this}}{{/unique}}');
+      assert.equal(fn(context), '');
+    });
+    it('should return array with unique items', function() {
+      var fn = hbs.compile('{{#unique duplicate}}{{this}}{{/unique}}');
+      assert.equal(fn(context).toString(), 'a,b,c,d,f,g');
+    });
+  });
+  
 });