Add delete function to ManyMany

Allows deleting the intermediate maphper entries that match the id of the current object

Maphper/Relation/ManyMany.php

@@ -111,4 +111,8 @@ private function offsetSetAutotraverse($value, $relatedField, $valueField) {
 	public function offsetUnset($id) {
 		//$this->relation->mapper->filter([$relatedField => $this->object->$valueField, $this->relation->parentField => $id])->delete();
 	}
+
+	public function delete() {
+		$this->getResults()->delete();
+	}
 }

tests/MySqlDatabaseTest.php

@@ -1123,6 +1123,25 @@ public function testManyManyGetByIndexNotExist() {
 			$this->assertFalse(isset($actors[1]->movies[2]));
 	}
 
+	public function testDeleteManyMany() {
+		list($actors, $movies, $cast) = $this->setUpMoviesActors();
+
+		// Set up some relations
+		$actors[1]->movies[] = $movies[2];
+		$actors[1]->movies[] = $movies[3];
+		$actors[2]->movies[] = $movies[2];
+		$actors[2]->movies[] = $movies[1];
+
+		$this->assertNotEquals(0, count($cast));
+		$this->assertEquals(4, count($cast));
+
+		$actors[1]->movies->delete();
+
+		$this->assertEquals(2, count($cast));
+		$this->assertEquals(0, count($actors[1]->movies));
+		$this->assertEquals(2, count($actors[2]->movies));
+	}
+
 
 	private function setupMoviesActorsReal() {
 		$cast = new \Maphper\Maphper($this->getDataSource('cast', ['movieId', 'actorId'], ['editmode' => true]));