如何使用 Jest 测试两个参数是否为数字

Question

I got a function which receives two numbers (integer), returning an array with the firsts (numbers) multiple of (value) like countBy(value, number).

eg

countBy(1, 10) returns [1, 2, 3, 4, 5, 5, 7, 8, 9, 10]

countyBy(2, 5) returns [2, 4, 6, 8, 10]

So, what matcher should be used to test if the function receives only numbers (integer) ? I did a lot of tests but still did not find a solution.

it ('Verify if are received and returned only numbers', () => {
  expect(typeof countBy(2, 5)).toBe('number'); 
});

Does anybody can give me a light?

Answer 1

try this

test('Verify if are received and returned only numbers', () => {
  expect(countBy(2, 5)).toEqual(
    expect.arrayContaining([expect.any(Number)])
  );
});