Cloning a HeaderCollection yields deep copies of the Headers.

src/Message/Header/HeaderCollection.php

@@ -4,6 +4,11 @@ namespace WellRESTed\Message\Header;
 
 class HeaderCollection implements \ArrayAccess
 {
+    /**
+     * @var array
+     *
+     * Hash array with keys as lowercase header names, Header[] as values.
+     */
     private $headers;
 
     public function __construct()
@@ -11,16 +16,28 @@ class HeaderCollection implements \ArrayAccess
         $this->headers = [];
     }
 
+    /**
+     * @param string $offset
+     * @return bool
+     */
     public function offsetExists($offset)
     {
         return isset($this->headers[strtolower($offset)]);
     }
 
+    /**
+     * @param mixed $offset
+     * @return Header[]
+     */
     public function offsetGet($offset)
     {
         return $this->headers[strtolower($offset)];
     }
 
+    /**
+     * @param string $offset
+     * @param string $value
+     */
     public function offsetSet($offset, $value)
     {
         $header = new Header($offset, $value);
@@ -32,8 +49,27 @@ class HeaderCollection implements \ArrayAccess
         }
     }
 
+    /**
+     * @param string $offset
+     */
     public function offsetUnset($offset)
     {
         unset($this->headers[strtolower($offset)]);
     }
+
+    /**
+     * Make a deep copy of all headers in the arrays
+     */
+    public function __clone()
+    {
+        $originalHeaders = $this->headers;
+        $this->headers = [];
+        foreach ($originalHeaders as $name => $headers) {
+            $clonedHeaders = [];
+            foreach ($headers as $header) {
+                $clonedHeaders[] = clone $header;
+            }
+            $this->headers[$name] = $clonedHeaders;
+        }
+    }
 }

test/tests/unit/Message/Header/HeaderCollectionTest.php

@@ -74,4 +74,24 @@ class HeaderCollectionTest extends \PHPUnit_Framework_TestCase
         unset($collection["set-cookie"]);
         $this->assertFalse(isset($collection["set-cookie"]));
     }
+
+    /**
+     * @covers WellRESTed\Message\Header\HeaderCollection::__clone
+     * @uses WellRESTed\Message\Header\HeaderCollection::__construct
+     * @uses WellRESTed\Message\Header\HeaderCollection::offsetSet
+     * @uses WellRESTed\Message\Header\HeaderCollection::offsetExists
+     * @uses WellRESTed\Message\Header\HeaderCollection::offsetUnset
+     * @uses WellRESTed\Message\Header\Header
+     */
+    public function testCloneMakesDeepCopyOfHeaders()
+    {
+        $collection = new HeaderCollection();
+        $collection["Set-Cookie"] = "cat=Molly";
+
+        $clone = clone $collection;
+        unset($clone["Set-Cookie"]);
+
+        $this->assertTrue(isset($collection["set-cookie"]));
+        $this->assertFalse(isset($clone["set-cookie"]));
+    }
 }