node.js - 用茉莉花模拟模块

Question

我正在尝试为使用node.js 框架编写的服务器端逻辑编写一些单元测试。我想使用jasmine 库进行单元测试和模拟，因为我有点熟悉它。

现在，我尝试了类似的方法来模拟文件系统 read 函数：

'use strict';
var loginRedirectMiddleware = require('../server/loginRedirectMiddleware');
var fs = require('fs');
var util = require('../server/util');

describe('loginRedirectMiddleware', function(){
  spyOn(fs,'read');
...
});

现在我在使用spyOn 调用时遇到错误：

  1) loginRedirectMiddleware encountered a declaration exception
   Message:
     TypeError: Cannot call method 'spyOn' of null
   Stacktrace:
     TypeError: Cannot call method 'spyOn' of null
    at null.<anonymous> (/home/adebksi/Nauka/js-linkedin-connector/server_test/loginRedirectMiddlewareSpec.js:11:3)
    at Object.<anonymous> (/home/adebksi/Nauka/js-linkedin-connector/server_test/loginRedirectMiddlewareSpec.js:10:1)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (/home/adebksi/Nauka/js-linkedin-connector/node_modules/karma/node_modules/coffee-script/lib/coffee-script/coffee-script.js:211:36)
    at Function.Module._load (module.js:312:12)
    at Module.require (module.js:364:17)
    at require (module.js:380:17)
    at Object.jasmine.executeSpecsInFolder (/home/adebksi/Nauka/js-linkedin-connector/node_modules/grunt-jasmine-node/node_modules/jasmine-node/lib/jasmine-node/index.js:151:9)
    at Object.<anonymous> (/home/adebksi/Nauka/js-linkedin-connector/node_modules/grunt-jasmine-node/tasks/jasmine-node-task.js:110:19)
    at Object.thisTask.fn (/home/adebksi/Nauka/js-linkedin-connector/node_modules/grunt/lib/grunt/task.js:78:16)
    at Object.<anonymous> (/home/adebksi/Nauka/js-linkedin-connector/node_modules/grunt/lib/util/task.js:282:30)
    at Task.runTaskFn (/home/adebksi/Nauka/js-linkedin-connector/node_modules/grunt/lib/util/task.js:235:24)
    at Task.<anonymous> (/home/adebksi/Nauka/js-linkedin-connector/node_modules/grunt/lib/util/task.js:281:12)
    at Task.start (/home/adebksi/Nauka/js-linkedin-connector/node_modules/grunt/lib/util/task.js:290:5)
    at Object.grunt.tasks (/home/adebksi/Nauka/js-linkedin-connector/node_modules/grunt/lib/grunt.js:155:8)
    at Object.module.exports [as cli] (/home/adebksi/Nauka/js-linkedin-connector/node_modules/grunt/lib/grunt/cli.js:38:9)
    at Object.<anonymous> (/home/adebksi/.nvm/v0.10.15/lib/node_modules/grunt-cli/bin/grunt:41:20)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Function.Module.runMain (module.js:497:10)
    at startup (node.js:119:16)
    at node.js:901:3

我想知道我做错了什么？

当我执行console.log(typeof fs.read) 时，我得到function 所以这个属性是一个函数。

Answer 1

好吧，原来是我的错，我试图在describe函数中创建间谍，我应该把它放在it中。