public function testMerge() { $expression1 = new Expression(); $expression1->where('a', 77); $expression1->where('b', 88); $expression1->whereGreater('c', 99); $expression2 = new Expression(); $expression2->where('a', 55); $expression1->whereLess('c', 66); $expression1->merge($expression2); $this->assertEquals(array('a' => array(77, 55), 'b' => 88, 'c' => array('$gt' => 99, '$lt' => 66)), $expression1->toArray()); }