legacy argent rose code including Lanzarote Wine

long-legacy-argent-rose.ts

export class ArgentRoseStore  
    // ...

    private updateQuality(product: Product): void {
        if (product.isTheatrePasses()) {
            if (product.sellIn < 0) {
                product.dropQualityToMinimum();
            } else if (product.sellIn < 5) {
                product.increaseQualityBy(3);
            } else {
                product.increaseQualityBy(1);
            }
        } else if (product.isLanzaroteWine()) {
            product.increaseQualityBy(2);
        } else {
            product.decreaseQualityBy(2);
        }
    }

    /// ....
}

export class Product {
    /// ... 
    isLanzaroteWine() {
         return this.description === "Lanzarote Wine";
    }
    /// ... 
}

long-tests_100_coverage_but_many_mutants_alive.ts

it("Lanzarote Wine increases quality by one", async () => {
    const store = storeIncluding(lanzaroteWine(3, 10));

    await store.update();

    expect(store.getSavedInventory()).toEqual(inventoryIncluding(lanzaroteWine(2, 12)));
});

it("Expired Lanzarote Wine increases quality twice as fast", async () => {
    const store = storeIncluding(lanzaroteWine(-5, 10));

    await store.update();

    expect(store.getSavedInventory()).toEqual(inventoryIncluding(lanzaroteWine(-6, 14)));
}); 
 
function lanzaroteWine(sellIn: number, quality: number): Product {
    return new Product("Lanzarote Wine", sellIn, quality);
}