sum.test.js

const suma = require('./sum');

test('sumar 1 + 2 es igual a 3', () => {
  expect(suma(1, 2)).toBe(3);
});
test('asignacion de objeto', () => {
  const data = {uno: 1};
  data['dos'] = 2;
  expect(data).toEqual({uno: 1, dos: 2});
});

test('agregando un numero positivo que no sea 0', () => {
  for (let a = 1; a < 10; a++) {
    for (let b = 1; b < 10; b++) {
      expect(a + b).not.toBe(0);
    }
  }
});
test('null', () => {
  const n = null;
  //expect(n).toBeNull();
  expect(n).toBeDefined();
  /*expect(n).not.toBeUndefined();
  expect(n).not.toBeTruthy();
  expect(n).toBeFalsy();*/
});

test('cero', () => {
  const z = 0;
  expect(z).not.toBeNull();
  expect(z).toBeDefined();
  expect(z).not.toBeUndefined();
  expect(z).not.toBeTruthy();
  expect(z).toBeFalsy();
});
test('dos mas dos', () => {
  const value = 2 + 2;
  expect(value).toBeGreaterThan(3);
  expect(value).toBeGreaterThanOrEqual(3.5);
  expect(value).toBeLessThan(5);
  expect(value).toBeLessThanOrEqual(4.5);

  // toBe y toEqual son equivalentes para números
  expect(value).toBe(4);
  expect(value).toEqual(4);
});

test('adding floating point numbers', () => {
  const value = 0.1 + 0.2;
  //expect(value).toBe(0.3);           This won't work because of rounding error
  expect(value).toBeCloseTo(0.3); // This works.
});
test('no hay I en Team', () => {
  expect('team').not.toMatch(/I/);
});

test('hay "stop" en Christoph', () => {
  expect('Christoph').toMatch(/stop/);
});


const shoppingList = [
  'diapers',
  'kleenex',
  'trash bags',
  'paper towels',
  'beer',
];

test('the shopping list has beer on it', () => {
  expect(shoppingList).toContain('beer');
  expect(new Set(shoppingList)).toContain('beer');
});

function compileAndroidCode() {
  throw new Error('you are using the wrong JDK');
}

test('compiling android goes as expected', () => {
  expect(compileAndroidCode).toThrow();
  expect(compileAndroidCode).toThrow(Error);

  // You can also use the exact error message or a regexp
  expect(compileAndroidCode).toThrow('you are using the wrong JDK');
  expect(compileAndroidCode).toThrow(/JDK/);
});

/*
para callbacks
test('the data is peanut butter', () => {
  function callback(data) {
    expect(data).toBe('peanut butter');
  }

  fetchData(callback);
});

test('the data is peanut butter', done => {
  function callback(data) {
    try {
      expect(data).toBe('peanut butter');
      done();
    } catch (error) {
      done(error);
    }
  }

  fetchData(callback);
});
para promesas

test('the data is peanut butter', () => {
  return fetchData().then(data => {
    expect(data).toBe('peanut butter');
  });
});

*/