failingtest.ts

export class Calculator {
    public add(firstAddend: number, secondAddend: number): number {
        return 0;
    }
}

// ❌test fails since calculator doesn't sum the two numbers
describe('Calculator', () => {
    it('sums up two numbers properly', () => {
      calculator = new Calculator();
      expect(calculator.add(2,2)).to.equal(4);
    });
});