unit test with parameter input

Android parameterize test

as regular test using unit test we can use jUnit roboelectric Mockito etc. There are some condition which class with parameter more than 1
ex. inteface class

`double getPriceAfterSurcharge(double baseCost, double surchargeFixedPrice, double surchargePercentage, Integer quantity);`

implementation class:
@Override
public double getPriceAfterSurcharge(double baseCost, double surchargeFixedPrice,
                                     double surchargePercentage, Integer quantity) {
    double productPrice;

    if (surchargeFixedPrice > 0) {
        productPrice = (baseCost + surchargeFixedPrice);
    } else if (surchargePercentage > 0) {//5000 + ((20/100) * 5000) = 5000 + 1000 = 6000
        productPrice = Utils.getRoundedNum(baseCost + ((surchargePercentage / 100) * baseCost));
    } else {
        productPrice = baseCost;
    }

    if (quantity != null) {//600.000
        productPrice *= quantity;
    }

    return productPrice;
}

for this class could make some condition with variation value as input to make it more concise to test and more robust to get output value as expected.
example, in unit test class we can pass value
case 1: 5000d, 300d, 0d, 100 -> expected return 530000
case 2: 5000, 0, 20, 100 -> expected return 600000
case 3: 0, 0, 20, 100 -> expected return 0

in unit test class would be like this,
@Test
public void testGetPriceAfterSurcharge() {
    double baseCost = 5000;
    double surchargeFixedPrice = 300;
    double surchargePercentage = 20;
    Integer quantity = 100;

    //surcharge fix price
    double expected = 530000;
    double actual = cartItemRepository.getPriceAfterSurcharge(baseCost, surchargeFixedPrice, 0d, quantity);

    assertEquals(expected, actual, 0d);

    //surcharge percentage
    expected = 600000;
    actual = cartItemRepository.getPriceAfterSurcharge(baseCost, 0d, surchargePercentage, quantity);

    assertEquals(expected, actual, 0d);

    //base cost 0
    expected = 0d;
    actual = cartItemRepository.getPriceAfterSurcharge(0d, 0d, surchargePercentage, quantity);

    assertEquals(expected, actual, 0d);
}

didn't it take some times to add more use case?
By using library `testImplementation 'pl.pragmatists:JUnitParams:1.1.1'` in gradle android would help save tima
- sync gradle after add that one.
- create class and give annotation `@Runwith(JUnitParamsRunner.class)`
- create method to test then along parameters needed, by this case would be 
@Test
@Parameters(method = "inputParams")
public void testGetPriceAfterSurcharge(double baseCost
        , double surchargeFixedPrice
        , double surchargePercentage
        , Integer quantity
        , double expectedReturn) {
}
- did you see annotation `@Parameters`? that gonna tell IDE which method gonna use as parameter input.
- create method which place all case input parameter, by this case would be
private Object inputParams() {
    return new Object[][]{
            //baseCost, surchargeFixedPrice, surchargePercentage, quantity, expectedReturn
            {5000d, 300d, 0d, 100, 530000}
            , {5000, 0, 20, 100, 600000}
            , {0, 0, 20, 100, 0}
            //more input use case here
    };
} 
clear enough?
- implement assert by calling method on real class to test along with assert
- run the test class as usual