Lorenzo's suggested changes to appendItem

src/Collection/CollectionTrait.php

@@ -411,6 +411,42 @@ public function append($items)
         return new Collection($list);
     }
 
+    /**
+     * {@inheritDoc}
+     */
+    public function appendItem($item, $key = null)
+    {
+        if ($key !== null) {
+            $data = [$key => $item];
+        } else {
+            $data = [$item];
+        }
+
+        return $this->append($data);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function prepend($items)
+    {
+        return (new Collection($items))->append($this);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function prependItem($item, $key = null)
+    {
+        if ($key !== null) {
+            $data = [$key => $item];
+        } else {
+            $data = [$item];
+        }
+
+        return $this->prepend($data);
+    }
+
     /**
      * {@inheritDoc}
      */

tests/TestCase/Collection/CollectionTest.php

@@ -1149,6 +1149,65 @@ public function testAppend()
         $this->assertEquals(['a' => 4, 'b' => 2, 'c' => 3], $combined->toArray());
     }
 
+    /**
+     * Tests the appendItem method
+     */
+    public function testAppendItem()
+    {
+        $collection = new Collection([1, 2, 3]);
+        $combined = $collection->appendItem(4);
+        $this->assertEquals([1, 2, 3, 4], $combined->toArray(false));
+
+        $collection = new Collection(['a' => 1, 'b' => 2]);
+        $combined = $collection->appendItem(3, 'c');
+        $combined = $combined->appendItem(4, 'a');
+        $this->assertEquals(['a' => 4, 'b' => 2, 'c' => 3], $combined->toArray());
+    }
+
+    /**
+     * Tests the prepend method
+     */
+    public function testPrepend()
+    {
+        $collection = new Collection([1, 2, 3]);
+        $combined = $collection->prepend(['a']);
+        $this->assertEquals(['a', 1, 2, 3], $combined->toArray());
+
+        $collection = new Collection(['c' => 3, 'd' => 4]);
+        $combined = $collection->prepend(['a' => 1, 'b' => 2]);
+        $this->assertEquals(['a' => 1, 'b' => 2, 'c' => 3, 'd' => 4], $combined->toArray());
+    }
+
+    /**
+     * Tests prependItem method
+     */
+    public function testPrependItem()
+    {
+        $collection = new Collection([1, 2, 3]);
+        $combined = $collection->prependItem('a');
+        $this->assertEquals(['a', 1, 2, 3], $combined->toList());
+
+        $collection = new Collection(['c' => 3, 'd' => 4]);
+        $combined = $collection->prependItem(2, 'b');
+        $combined = $combined->prependItem(1, 'a');
+        $this->assertEquals(['a' => 1, 'b' => 2, 'c' => 3, 'd' => 4], $combined->toArray());
+    }
+
+    /**
+     * Tests prependItem method
+     */
+    public function testPrependItemPreserveKeys()
+    {
+        $collection = new Collection([1, 2, 3]);
+        $combined = $collection->prependItem('a');
+        $this->assertEquals(['a', 1, 2, 3], $combined->toList());
+
+        $collection = new Collection(['c' => 3, 'd' => 4]);
+        $combined = $collection->prependItem(2, 'b');
+        $combined = $combined->prependItem(1, 'a');
+        $this->assertEquals(['a' => 1, 'b' => 2, 'c' => 3, 'd' => 4], $combined->toArray());
+    }
+
     /**
      * Tests the append method with iterator
      */