When a test fails, its name is the first indication of what may have gone wrong.
Bad:
describe('Calendar', () => {
it('2/29/2020', () => {
// ...
});
it('throws', () => {
// ...
});
});
Good:
describe('Calendar', () => {
it('should handle leap year', () => {
// ...
});
it('should throw when format is invalid', () => {
// ...
});
});