Merge pull request #948 from baijunyao/feature/add-first-and-last-fun…

…citon-to-collection

Add `first()` and `last()` functions to `Collection`

lib/Collection.php

@@ -241,6 +241,26 @@ public function previousPage($params = null, $opts = null)
         return $this->all($params, $opts);
     }
 
+    /**
+     * Gets the first item from the current page. Returns `null` if the current page is empty.
+     *
+     * @return null|\Stripe\StripeObject
+     */
+    public function first()
+    {
+        return \count($this->data) > 0 ? $this->data[0] : null;
+    }
+
+    /**
+     * Gets the last item from the current page. Returns `null` if the current page is empty.
+     *
+     * @return null|\Stripe\StripeObject
+     */
+    public function last()
+    {
+        return \count($this->data) > 0 ? $this->data[\count($this->data) - 1] : null;
+    }
+
     private function extractPathAndUpdateParams($params)
     {
         $url = \parse_url($this->url);

tests/Stripe/CollectionTest.php

@@ -312,4 +312,28 @@ public function testPreviousPage()
         $previousPage = $this->fixture->previousPage();
         static::assertSame([], $previousPage->data);
     }
+
+    public function testFirst()
+    {
+        $collection = Collection::constructFrom([
+            'data' => [
+                ['content' => 'first'],
+                ['content' => 'middle'],
+                ['content' => 'last'],
+            ],
+        ]);
+        static::assertSame('first', $collection->first()['content']);
+    }
+
+    public function testLast()
+    {
+        $collection = Collection::constructFrom([
+            'data' => [
+                ['content' => 'first'],
+                ['content' => 'middle'],
+                ['content' => 'last'],
+            ],
+        ]);
+        static::assertSame('last', $collection->last()['content']);
+    }
 }