import org.assertj.core.api.Assertions; import org.junit.jupiter.api.BeforeEach; import org.junit.jupiter.api.Disabled; import org.junit.jupiter.api.DisplayName; import org.junit.jupiter.api.Test; import java.util.Arrays; import java.util.Collections; import java.util.List; import static org.assertj.core.api.Assertions.assertThat; public class BookStoreTest { // This is sufficient accuracy since we're handling currency values, which should be equal // to within 2 decimal places. private static final double EQUALITY_TOLERANCE = 0.001; private BookStore bookStore; @BeforeEach public void setUp() { bookStore = new BookStore(); } @Test @DisplayName("Only a single book") public void onlyASingleBook() { List books = Collections.singletonList(1); assertThat(bookStore.calculateBasketCost(books)) .isCloseTo(8.00, Assertions.offset(EQUALITY_TOLERANCE)); } @Disabled("Remove to run test") @Test @DisplayName("Two of the same book") public void twoOfSameBook() { List books = Arrays.asList(2, 2); assertThat(bookStore.calculateBasketCost(books)) .isCloseTo(16.00, Assertions.offset(EQUALITY_TOLERANCE)); } @Disabled("Remove to run test") @Test @DisplayName("Empty basket") public void emptyBasket() { List books = Collections.emptyList(); assertThat(bookStore.calculateBasketCost(books)) .isCloseTo(0.00, Assertions.offset(EQUALITY_TOLERANCE)); } @Disabled("Remove to run test") @Test @DisplayName("Two different books") public void twoDifferentBooks() { List books = Arrays.asList(1, 2); assertThat(bookStore.calculateBasketCost(books)) .isCloseTo(15.20, Assertions.offset(EQUALITY_TOLERANCE)); } @Disabled("Remove to run test") @Test @DisplayName("Three different books") public void threeDifferentBooks() { List books = Arrays.asList(1, 2, 3); assertThat(bookStore.calculateBasketCost(books)) .isCloseTo(21.60, Assertions.offset(EQUALITY_TOLERANCE)); } @Disabled("Remove to run test") @Test @DisplayName("Four different books") public void fourDifferentBooks() { List books = Arrays.asList(1, 2, 3, 4); assertThat(bookStore.calculateBasketCost(books)) .isCloseTo(25.60, Assertions.offset(EQUALITY_TOLERANCE)); } @Disabled("Remove to run test") @Test @DisplayName("Five different books") public void fiveDifferentBooks() { List books = Arrays.asList(1, 2, 3, 4, 5); assertThat(bookStore.calculateBasketCost(books)) .isCloseTo(30.00, Assertions.offset(EQUALITY_TOLERANCE)); } @Disabled("Remove to run test") @Test @DisplayName("Two groups of four is cheaper than group of five plus group of three") public void twoGroupsOfFourIsCheaperThanGroupOfFivePlusGroupOfThree() { List books = Arrays.asList(1, 1, 2, 2, 3, 3, 4, 5); assertThat(bookStore.calculateBasketCost(books)) .isCloseTo(51.20, Assertions.offset(EQUALITY_TOLERANCE)); } @Disabled("Remove to run test") @Test @DisplayName("Two groups of four is cheaper than groups of five and three") public void twoGroupsOfFourIsCheaperThanGroupsOfFiveAndThree() { List books = Arrays.asList(1, 1, 2, 3, 4, 4, 5, 5); assertThat(bookStore.calculateBasketCost(books)) .isCloseTo(51.20, Assertions.offset(EQUALITY_TOLERANCE)); } @Disabled("Remove to run test") @Test @DisplayName("Group of four plus group of two is cheaper than two groups of three") public void groupOfFourPlusGroupOfTwoIsCheaperThanTwoGroupsOfThree() { List books = Arrays.asList(1, 1, 2, 2, 3, 4); assertThat(bookStore.calculateBasketCost(books)) .isCloseTo(40.80, Assertions.offset(EQUALITY_TOLERANCE)); } @Disabled("Remove to run test") @Test @DisplayName("Two each of first four books and one copy each of rest") public void twoEachOfFirst4BooksAnd1CopyEachOfRest() { List books = Arrays.asList(1, 1, 2, 2, 3, 3, 4, 4, 5); assertThat(bookStore.calculateBasketCost(books)) .isCloseTo(55.60, Assertions.offset(EQUALITY_TOLERANCE)); } @Disabled("Remove to run test") @Test @DisplayName("Two copies of each book") public void twoCopiesOfEachBook() { List books = Arrays.asList(1, 1, 2, 2, 3, 3, 4, 4, 5, 5); assertThat(bookStore.calculateBasketCost(books)) .isCloseTo(60.00, Assertions.offset(EQUALITY_TOLERANCE)); } @Disabled("Remove to run test") @Test @DisplayName("Three copies of first book and two each of remaining") public void threeCopiesOfFirstBookAndTwoEachOfRemaining() { List books = Arrays.asList(1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 1); assertThat(bookStore.calculateBasketCost(books)) .isCloseTo(68.00, Assertions.offset(EQUALITY_TOLERANCE)); } @Disabled("Remove to run test") @Test @DisplayName("Three each of first two books and two each of remaining books") public void threeEachOfFirstTwoBooksAndTwoEachOfRemainingBooks() { List books = Arrays.asList(1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 1, 2); assertThat(bookStore.calculateBasketCost(books)) .isCloseTo(75.20, Assertions.offset(EQUALITY_TOLERANCE)); } @Disabled("Remove to run test") @Test @DisplayName("Four groups of four are cheaper than two groups each of five and three") public void fourGroupsOfFourAreCheaperThanTwoGroupsEachOfFiveAndThree() { List books = Arrays.asList(1, 1, 2, 2, 3, 3, 4, 5, 1, 1, 2, 2, 3, 3, 4, 5); assertThat(bookStore.calculateBasketCost(books)) .isCloseTo(102.4, Assertions.offset(EQUALITY_TOLERANCE)); } @Disabled("Remove to run test") @Test @DisplayName( "Check that groups of four are created properly even when there are more groups of three than groups of five" ) public void groupsOfFourAreCreatedEvenWhenThereAreMoreGroupsOfThreeThanGroupsOfFive() { List books = Arrays.asList(1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 5, 5); assertThat(bookStore.calculateBasketCost(books)) .isCloseTo(145.6, Assertions.offset(EQUALITY_TOLERANCE)); } @Disabled("Remove to run test") @Test @DisplayName("One group of one and four is cheaper than one group of two and three") public void oneGroupOfOneAndFourIsCheaperThanOneGroupOfTwoAndThree() { List books = Arrays.asList(1, 1, 2, 3, 4); assertThat(bookStore.calculateBasketCost(books)) .isCloseTo(33.6, Assertions.offset(EQUALITY_TOLERANCE)); } @Disabled("Remove to run test") @Test @DisplayName("One group of one and two plus three groups of four is cheaper than one group of each size") public void oneGroupOfOneAndTwoPlusThreeGroupsOfFourIsCheaperThanOneGroupOfEachSize() { List books = Arrays.asList(1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 5); assertThat(bookStore.calculateBasketCost(books)) .isCloseTo(100.0, Assertions.offset(EQUALITY_TOLERANCE)); } }