如何使用Mocha Chai单元测试来测试具有两个字符串参数的函数

npm install mocha chai

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

describe('concatStrings', function() {
  it('should concatenate two strings', function() {
    const result = concatStrings('Hello', ' World');
    assert.equal(result, 'Hello World');
  });
});

function concatStrings(str1, str2) {
  return str1 + str2;
}

mocha test.js

  concatStrings
    ✓ should concatenate two strings

  1 passing (10ms)