Added function to check non-unique array element in response.

Author: alekdavis

README.md

@@ -338,6 +338,8 @@ Expects HTTP response to return an empty JSON collection.
 Expects HTTP response to return a JSON collection with a single element.
 * [`utils.expect.response.not.empty`](#utilsexpectresponsenotempty):
 Expects HTTP response to return a non-empty JSON collection.
+* [`utils.expect.response.not.unique`](#utilsexpectresponsenotunique):
+Expects HTTP response to return a JSON collection with two or more items.
 
 ### `utils.expect.response.text`
 Expects HTTP response to return a simple (not the JSON) data type, such as string.
@@ -385,8 +387,9 @@ utils.expect.response.one(pm);
 Expects HTTP response to return a JSON collection (can be empty or contain the specified minimum and/or maximum number of items). The `utils.expect.response.many` function can be called via one of these shortcuts:
 
 * [`utils.expect.response.empty`](#utilsexpectresponseempty) to check for an empty collection
-* [`utils.expect.response.not.empty`](#utilsexpectresponsenotempty) to check for a non-empty collection
 * [`utils.expect.response.unique`](#utilsexpectresponseunique) to check for a collection with a single (unique) item
+* [`utils.expect.response.not.empty`](#utilsexpectresponsenotempty) to check for a non-empty collection
+* [`utils.expect.response.not.unique`](#utilsexpectresponsenotunique) to check for a collection with multiple items
 
 #### Prototype
 ```JavaScript
@@ -448,6 +451,20 @@ Check if the HTTP response data contains a JSON collection with at least one ite
 utils.expect.response.not.empty(pm);
 ```
 
+### `utils.expect.response.not.unique`
+Expects HTTP response to return a JSON collection with at least two items.
+
+#### Prototype
+```JavaScript
+utils.expect.response.not.unique(pm)
+```
+
+#### Example
+Check if the HTTP response data contains a JSON collection with at least two items.
+```JavaScript
+utils.expect.response.not.unique(pm);
+```
+
 ## Property validation functions
 Property validation functions check named properties of the specified objects. The primary benefits of these functions (compared to the underlying [Chai assertions](https://www.chaijs.com/api/bdd/) they use) is that they (a) always check to make sure that the properties exist before additional validation (so you can skip one test step) and (b) generate more complete error messages on assertion failures (the default assertion errors do not mention named of the properties being checked, which makes them not that useful). Property validation functions are grouped under the `utils.expect.property` namespace and include:
 

utils.js

@@ -621,6 +621,11 @@ utils = {
             // Expects response to contain an non-empty array.
             empty: function(pm) {
                 utils.expect.response.many(pm, 1, -1);
+            },
+            // DESCRITION
+            // Expects response to contain an array with at least two items.
+            unique: function(pm) {
+                utils.expect.response.many(pm, 2, -1);
             }
         }
     // End of 'utils.expect.response' functions.