11. Solution: Additional Unit Test Topics

Solution: Unit Test Lifecycle

Sample Solution Class

This isn't something you would normally use @BeforeAll to do, but it is a demonstration of how the annotation interacts with the unit test lifecycle. Here is a sample solution class:

TotalsWithDiscountCalculatorTest.java

import com.udacity.cart.model.CartItem;
import com.udacity.cart.model.CartTotals;
import com.udacity.cart.model.User;
import com.udacity.cart.model.UserType;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.RepeatedTest;
import org.junit.jupiter.api.RepetitionInfo;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.Arguments;
import org.junit.jupiter.params.provider.MethodSource;

import java.util.List;
import java.util.stream.Stream;

import static org.junit.jupiter.api.Assertions.*;

class TotalsWithDiscountCalculatorTest {

    static User globalUser;
    TotalsWithDiscountCalculator totalsWithDiscountCalculator;

    @BeforeAll
    static void setupGlobalUser() {
        System.out.println("Setting up a global User");
        globalUser = new User("Global User", UserType.REGULAR, 100.00);
    }

    @BeforeEach
    void setupCalculator() {
        System.out.println("Setting up a new calculator");
        totalsWithDiscountCalculator = new TotalsWithDiscountCalculator(globalUser);
    }

    @RepeatedTest(3)
    void getTotalsWithDiscounts_userWithCredit_chargedMultipleTimes(RepetitionInfo repetitionInfo) {
        totalsWithDiscountCalculator.getTotals(List.of(new CartItem("Twenty dollar item", 20.0, 0)));
        assertEquals(100.0 - 20 * repetitionInfo.getCurrentRepetition(), globalUser.getCredit());
    }


    @ParameterizedTest
    @MethodSource("differentUserTypesAndExpectedTotals")
    void getTotalsWithDiscounts_regularAndPlatinumUser_returnsDifferentSubtotal(User user, CartTotals expectedCartTotals) {
        TotalsWithDiscountCalculator calculator = new TotalsWithDiscountCalculator(user);

        CartTotals totals = calculator.getTotals(List.of(new CartItem("Ten dollar item", 10.0, 1.0)));

        assertEquals(expectedCartTotals, totals);

    }

    private static Stream<Arguments> differentUserTypesAndExpectedTotals() {
        return Stream.of(
            Arguments.of(
                new User("Regular User", UserType.REGULAR, 0.0),
                new CartTotals(10.0, 1.0)
            ),
            Arguments.of(
                new User("Platinum User", UserType.PLATINUM, 0.0),
                new CartTotals(9.0, 1.0)
            )
        );
    }
}