Mocha.js：即使测试套件失败也要运行“after”钩子

Javascript
const assert = require('assert');
describe('Math', function() {
  before(function() {
    // 执行一些准备工作
  });
  after(function() {
    // 执行一些清理工作
  });
  it('should return the sum of two numbers', function() {
    const result = 1 + 2;
    assert.equal(result, 3);
  });
  it('should return the difference of two numbers', function() {
    const result = 5 - 3;
    assert.equal(result, 2);
  });
  it('should return the product of two numbers', function() {
    const result = 2 * 3;
    assert.equal(result, 6);
  });
  it('should return the quotient of two numbers', function() {
    const result = 6 / 3;
    assert.equal(result, 2);
  });
});