Tests with no relevant mutants surviving but missing important test cases

ArgentRoseStoreTest.java

package com.argentrose;

import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.ValueSource;

import java.util.Arrays;

import static org.assertj.core.api.Assertions.assertThat;

public class ArgentRoseStoreTest {

    private static final int MIN_QUALITY = 0;
    private static final int MAX_QUALITY = 50;

    @Test
    @DisplayName("Updating a non expired regular product decreases its quality by 2 and decreases its sell-in by 1")
    void not_expired_regular_product_update() {
        ArgentRoseStore store = argentRoseStoreWith(regularProduct(1, 3));

        store.update();

        assertThat(store).isEqualTo(argentRoseStoreWith(regularProduct(0, 1)));
    }

    @Test
    @DisplayName("Non expired regular product's updated quality can not be negative")
    void not_expired_regular_product_updated_quality_can_not_be_negative() {
        ArgentRoseStore store = argentRoseStoreWith(regularProduct(30, 1));

        store.update();

        assertThat(store).isEqualTo(argentRoseStoreWith(regularProduct(29, MIN_QUALITY)));
    }

    @Test
    @DisplayName("Already expired regular product decreases quality twice as fast")
    void already_expired_regular_product_update() {
        ArgentRoseStore store = argentRoseStoreWith(regularProduct(0, 5));

        store.update();

        assertThat(store).isEqualTo(argentRoseStoreWith(regularProduct(-1, 1)));
    }

    @Test
    @DisplayName("Already expired regular product's updated quality can not be negative")
    void already_expired_regular_product_updated_quality_can_not_be_negative() {
        ArgentRoseStore store = argentRoseStoreWith(regularProduct(-1, 3));

        store.update();

        assertThat(store).isEqualTo(argentRoseStoreWith(regularProduct(-2, MIN_QUALITY)));
    }

    @Test
    @DisplayName("Theatre Passes increases quality by 1 when sell-in is greater than 6 days")
    void theatre_passes_quality_increases_by_1_when_sellIn_greater_than_6() {
        ArgentRoseStore store = argentRoseStoreWith(theatrePasses(7, 5));

        store.update();

        assertThat(store).isEqualTo(argentRoseStoreWith(theatrePasses(6, 6)));
    }

    @Test
    @DisplayName("Theatre Passes's quality can't grow over 50 when sell-in is greater than 6 days")
    void theatre_passes_quality_cant_grow_over_50_when_sell_in_is_greater_than_6_days() {
        ArgentRoseStore store = argentRoseStoreWith(theatrePasses(20, MAX_QUALITY));

        store.update();

        assertThat(store).isEqualTo(argentRoseStoreWith(theatrePasses(19, MAX_QUALITY)));
    }

    @ParameterizedTest
    @ValueSource(ints = {1, 6})
    @DisplayName("Theatre Passes increases quality by 3 when sell-in is between 1 and 6 days")
    void theatre_passes_quality_increases_by_3_when_sellIn_between_1_and_6(int sellIn) {
        ArgentRoseStore store = argentRoseStoreWith(theatrePasses(sellIn, 46));

        store.update();

        assertThat(store).isEqualTo(argentRoseStoreWith(theatrePasses(sellIn - 1, 49)));
    }

    @Test
    @DisplayName("Theatre Passes quality can't grow over 50 when sell-in is between 1 and 6 days")
    void theatre_passes_quality_cant_exceed_50_when_sellIn_between_1_and_6() {
        ArgentRoseStore store = argentRoseStoreWith(theatrePasses(4, 48));

        store.update();

        assertThat(store).isEqualTo(argentRoseStoreWith(theatrePasses(3, MAX_QUALITY)));
    }

    @Test
    @DisplayName("Theatre Passes quality drops to 0 when expired")
    void theatre_passes_quality_drops_to_0_when_expired() {
        ArgentRoseStore store = argentRoseStoreWith(theatrePasses(0, 38));

        store.update();

        assertThat(store).isEqualTo(argentRoseStoreWith(theatrePasses(-1, MIN_QUALITY)));
    }

    private Product theatrePasses(int sellIn, int quality) {
        return new Product("Theatre Passes", sellIn, quality);
    }

    private Product regularProduct(int sellIn, int quality) {
        return new Product("any not special product", sellIn, quality);
    }

    private ArgentRoseStore argentRoseStoreWith(Product... products) {
        return new ArgentRoseStore(Arrays.asList(products));
    }
}