assertEquals(1, BasicMath::square(1)); $this->assertEquals(1.44, BasicMath::square(1.2)); $this->assertEquals(4, BasicMath::square(2)); } public function testSum(): void { $arr = [1, 1, 1, 1]; $func_return = function ($f) { return $f; }; $func_double = function ($f) { return $f * 2; }; $this->assertEquals(4, BasicMath::sum($arr, $func_return)); $this->assertEquals(8, BasicMath::sum($arr, $func_double)); } }