摩卡全球范围问题

Question

围绕我正在使用的全局对象进行mocha测试时遇到了很大问题.我能够生成以下MRE,它没有给出完全相同的错误,但举例说明了有问题的(错误的？)行为.任何见解都会非常感激.

我有以下main.js文件/lib:

exports.exec = function(){
  console.log(test);
}

然后是以下内容/test/test.js:

var should = require('should');
var main = require('../lib/main');

global.test = {something: 1};

describe('normal test', function(){
  beforeEach(function(){
    global.test = {another: 2};
  }),

  afterEach(function(){
    delete global.test;
  });

  it ('might work with global', function(){
    main.exec();
  })
});

最后,这是test/test2.js:

var should = require('should');
var main = require('../lib/main');

global.test = {third: 3};

describe('some test', function(){
  it ('messes up global', function(){
    main.exec();
  })
});

我希望第一个测试输出{another:2},第二个测试打印{third: 3}.实际上,这是我独立运行每个测试时得到的行为.例如

jeff@ubuntu:~/workspace/mocha-test$ mocha test/test2.js 

  { third: 3 }
?

  1 passing (6ms)

但是,当使用npm包should和mocha(1.16.1)运行测试时,我得到以下输出:

jeff@ubuntu:~/workspace/mocha-test$ mocha

  { another: 2 }
??

  1 passing (6ms)
  1 failing

  1) some test messes up global:
     ReferenceError: test is not defined
      at Object.exports.exec (/home/jeff/workspace/mocha-test/lib/main.js:3:15)
      at Context.<anonymous> (/home/jeff/workspace/mocha-test/test/test2.js:8:10)
      at Test.Runnable.run (/usr/lib/node_modules/mocha/lib/runnable.js:211:32)
      at Runner.runTest (/usr/lib/node_modules/mocha/lib/runner.js:355:10)
      at /usr/lib/node_modules/mocha/lib/runner.js:401:12
      at next (/usr/lib/node_modules/mocha/lib/runner.js:281:14)
      at /usr/lib/node_modules/mocha/lib/runner.js:290:7
      at next (/usr/lib/node_modules/mocha/lib/runner.js:234:23)
      at Object._onImmediate (/usr/lib/node_modules/mocha/lib/runner.js:258:5)
      at processImmediate [as _immediateCallback] (timers.js:330:15)

Answer 1

test2.js 应该像这样结构:

describe('some test', function(){
  before(function (){
    global.test = {third: 3};
  });

  it ('messes up global', function(){
    main.exec();
  })
});

关于GitHub问题的travisjeffery在评论中提到:

mocha加载文件然后运行套件,以可靠地设置测试,设置应该在套件中.

正如@SB指出的那样,这可能不适合跨测试分享全局变量之类的东西.