assertSame(0, $service->getGradeLevel('K')); $this->assertSame(99, $service->getGradeLevel('Y')); $this->assertSame(3, $service->getGradeLevel('3-A')); $this->assertSame(999, $service->getGradeLevel('Unknown')); } public function test_compare_grades_orders_numeric_then_suffix(): void { $service = new FeeGradeService(); $this->assertSame(-1, $service->compareGrades('2', '3')); $this->assertSame(-1, $service->compareGrades('3-A', '3-B')); $this->assertSame(1, $service->compareGrades('4', '3')); } }