Add tests for filter and without methods

Signed-off-by: Yoshi2889 <rick.2889@gmail.com>

tests/CollectionTest.php

@@ -80,4 +80,32 @@ public function testInvalidType()
 		$this->expectException(InvalidArgumentException::class);
 		$collection->offsetSet('test', 10);
 	}
+
+	public function testFilter()
+	{
+		$initialValues = ['Test', 'ing', 'something', 'else'];
+		$collection = new Collection($this->getStringValidatorClosure(), $initialValues);
+
+		$filteredCollection = $collection->filter(function (string $value)
+		{
+			return $value != 'else';
+		});
+
+		self::assertEquals(['Test', 'ing', 'something'], $filteredCollection->values());
+		self::assertEquals(3, $filteredCollection->count());
+	}
+
+	public function testWithout()
+	{
+		$initialValues = ['Test', 'ing', 'something', 'else'];
+		$collection = new Collection($this->getStringValidatorClosure(), $initialValues);
+
+		$filteredCollection = $collection->without(function (string $value)
+		{
+			return $value != 'else';
+		});
+
+		self::assertEquals(['else'], $filteredCollection->values());
+		self::assertEquals(1, $filteredCollection->count());
+	}
 }