Merge pull request #1 from 2dotstwice/feature/III-484

III-484: Add contains method.

Author: cyberwolf

src/AbstractCollection.php

@@ -67,6 +67,23 @@ public function withoutKey($key)
         return $copy;
     }
 
+    /**
+     * @inheritdoc
+     */
+    public function contains($item)
+    {
+        $this->guardObjectType($item);
+
+        $filtered = array_filter(
+            $this->items,
+            function ($itemToCompare) use ($item) {
+                return ($item == $itemToCompare);
+            }
+        );
+
+        return !empty($filtered);
+    }
+
     /**
      * @inheritdoc
      */

src/CollectionInterface.php

@@ -61,6 +61,17 @@ public function without($item);
      */
     public function withoutKey($key);
 
+    /**
+     * @param mixed $item
+     *   Item to check if it's present in the collection.
+     *
+     * @return bool
+     *
+     * @throws \InvalidArgumentException
+     *   When the provided item is of an incorrect type.
+     */
+    public function contains($item);
+
     /**
      * @param string $key
      *   Key to find the corresponding item for.

tests/CollectionTest.php

@@ -180,6 +180,28 @@ public function it_throws_an_exception_when_removing_by_unknown_key()
         $collection->withoutKey('foo3');
     }
 
+    /**
+     * @test
+     */
+    public function it_can_check_if_the_collection_contains_a_given_item()
+    {
+        $collection = (new FooCollection())
+            ->withKey('foo1', $this->foo1);
+
+        $this->assertTrue($collection->contains($this->foo1));
+    }
+
+    /**
+     * @test
+     */
+    public function it_can_check_if_the_collection_does_not_contain_a_given_item()
+    {
+        $collection = (new FooCollection())
+            ->withKey('foo1', $this->foo1);
+
+        $this->assertFalse($collection->contains($this->foo2));
+    }
+
     /**
      * @test
      */