Writing Unit Tests with Jest

test('adds 1 + 2 to equal 3', () => {
  expect(sum(1, 2)).toBe(3);
  expect(sum(1, 2)).toEqual(3);
});

They are exactly the same
toBe checks reference equality, toEqual checks value equality
toBe and toEqual serve different comparison purposes: 1) toBe uses strict equality (===) comparison, 2) toEqual performs deep equality comparison of objects, 3) toBe is perfect for primitives like numbers and strings, 4) toEqual is better for comparing objects and arrays, 5) toBe fails when comparing objects with same content but different references, 6) toEqual compares object properties recursively, 7) toBe is more performant for simple comparisons, 8) Choosing the right matcher improves test reliability.
toBe is for numbers, toEqual is for strings
toBe is faster than toEqual