test
describe
expect
toBe
toEqual

test('test description', () => {
  //business logic...
})

describe('section to group similar test', () => {
  test('test 1', () => {
  	//business logic...
  })
  
  test('test 2', () => {
  	// another business logic...
  })
})

expect(2).toBe(2); // will pass
expect(true).toBe(false); // will fail

expect(["one", "two", "three"])
  .toEqual(["one", "two", "three"]); // will pass

expect({ name: "Sanjeev Yadav"})
  .toEqual({ name: "Sanjeev Yadav"}); // will pass

test('sum of 2 + 2 is 4', () => {
  const result = add(2, 2);
  expect(result).toBe(4);
});