thanhnguyennguyen / cff

const Stack = require('./index.js');

// put your tests here

test('test stack', () => {

    let stack = new Stack();

    stack.push(1);

    expect(stack.top()).toEqual(1);

    stack.push(2);

    stack.push(3);

    expect(stack.isEmpty()).toEqual(false);

    expect(stack.top()).toEqual(3);

    expect(stack.pop()).toEqual(3);

    expect(stack.pop()).toEqual(2);

    expect(stack.pop()).toEqual(1);

    expect(stack.pop()).toEqual(undefined);

    expect(stack.isEmpty()).toEqual(true);

});