text: import { calculateCost } from "../libs/billing-lib";
  test("Lowest tier", () => {
    const storage = 10;
  
    const cost = 4000;
    const expectedCost = calculateCost(storage);
  
    expect(cost).toEqual(expectedCost);
  });
  
  test("Middle tier", () => {
    const storage = 100;
  
    const cost = 20000;
    const expectedCost = calculateCost(storage);
  
    expect(cost).toEqual(expectedCost);
  });
  
  test("Highest tier", () => {
    const storage = 101;
  
    const cost = 10100;
    const expectedCost = calculateCost(storage);
  
    expect(cost).toEqual(expectedCost);
  });
  