如何检查nodejs函数的结果？

function add(a, b) {
  return a + b;
}

console.log(add(2, 3)); // 输出：5

const assert = require('chai').assert;

function add(a, b) {
  return a + b;
}

assert.equal(add(2, 3), 5);

const assert = require('chai').assert;

function add(a, b) {
  return a + b;
}

describe('add', function() {
  it('should return the sum of two numbers', function() {
    assert.equal(add(2, 3), 5);
  });
});