public function testIBU() { $this->assertEquals(25.365869680614512, Beercalc::ibu(6.4, 1.5, 60, 1.08, 5)); //Based off Palmer's Calculation $this->assertEquals(6.03108750923272, Beercalc::ibu(4.6, 1, 15, 1.08, 5)); //Based off Palmer's Calculation $this->assertEquals(null, Beercalc::ibu(null, 1, 15, 1.08, 5)); $this->assertEquals(null, Beercalc::ibu(null, null, 15, 1.08, 5)); $this->assertEquals(null, Beercalc::ibu(null, null, null, 1.08, 5)); $this->assertEquals(null, Beercalc::ibu(null, null, null, null, 5)); $this->assertEquals(null, Beercalc::ibu(null, null, null, 1.08, null)); $this->assertEquals(null, Beercalc::ibu(4.6, 1, 15, 1.08, "asdf")); }