javaScript的单元测试框架Unit.js介绍

原文：http://unitjs.com/guide/introduction.html

unit.js是一个javascript断言库，该库可以在node.js与浏览器上运行。它适用于任何测试runner和单元测试框架，如mocha、jasmine、karma、protractor(角度应用程序的E2E测试框架)、qunit等。

为了使用户按自己喜欢的方式编写单元测试，unit.js提供了一个很棒的API，该API拥有如下库的接口：

+ Unit.js (fluent style inpired by Atoum)
+ Assert (of Node.js)
+ Must.js
+ Should.js
+ Sinon.js
+ other friendly features.

为了使这篇文档相对简单，所有示例都使用mocha来运行(除了与其他测试runner相关的实例)。Unit.js支持依赖注入，并且可以扩展为一个认证系统的插件。这使Unit.js学习曲线非常短。 断言列表在API文档中有完整记录，断言表达式如下：

test.string('hello');
test.object(user).hasProperty('email');
test.array(fruit).hasValue('kiwi');

几个样式(Serveral styles)

基本样式(Basic)

var obj = {
  message : 'hello',
  name    : 'Nico'
};
var str = 'Hello world';
// Structure of a request object.
// By example, provided by Express framework and other modules.
var req = {
  headers: {
    'content-type': 'application/json'
  }
};
test.object(obj).hasProperty('name');
test.object(obj).hasProperty('message', 'hello');
test.string(str).startsWith('Hello');
test.string(str).contains('world');
test.string(str).match(/[a-zA-Z]/);
test.value(req).hasHeader('content-type');
test.value(req).hasHeader('content-type', 'application/json');
// or
test.value(req).hasHeaderJson();

流样式(Fluent)

var obj = {message: 'hello', name: 'Nico'};
var str = 'Hello world';
// Structure of a request object.
// By example, provided by Express framework and other modules.
var req = {
  headers: {
    'content-type': 'application/json'
  }
};
test
  .object(obj)
    .hasProperty('name')
    .hasProperty('message', 'hello')
  .string(str)
    .startsWith('Hello')
    .contains('world')
    .match(/[a-zA-Z]/)
  .value(req)
    .hasHeader('content-type')
    // more precise
    .hasHeader('content-type', 'application/json')
    // or shortcut
    .hasHeaderJson()
;

表达式样式(Expressive)

var obj = {message: 'hello', name: 'Nico'};
var trigger = function(){
  throw new Error('Whoops !');
};
test
  .object(obj)
    .hasProperty('name')
    .hasProperty('message', 'hello')
  .when('Add "job" property', obj.job = 'developper')
  .then(function(){
    test.object(obj).hasProperty('job', 'developper');
  })
  .case('Delete all properties', function() {
    test
      .when(function() {
        delete obj.name;
        delete obj.message;
        delete obj.job;
      })
      .then(function(){
        test.object(obj).isEmpty();
      })
    ;
  })
  .if(obj.message = 'Hello world !')
  .and(obj.name = 'say hello')
  .string(obj.message)
    .startsWith('Hello')
    .endsWith('world !')
    .notContains('foobar')
  .given(obj = new Date(2014, 02))
  .date(obj)
    .isBefore(new Date(2020, 12))
    .isAfter(new Date(2010, 01))
    .isBetween(new Date(2014, 01), new Date(2014, 12))
  .then('Test the exception')
  .exception(trigger)
    .hasMessage('Whoops !')
    .hasMessage(/whoops/i)
    .isInstanceOf(Error)
  // or
  .error(trigger)
    .hasMessage('Whoops !')
    .hasMessage(/whoops/i)
;

集成好的断言库

Assert

// test 'string' type
test.assert(typeof 'foobar' == 'string');
// then that actual value '==' expected value
test.assert.equal('foobar', 'foobar');
// then that actual value '===' expected value
test.assert.strictEqual('foobar', 'foobar');
// this shortcut works also like this
var assert = test.assert;
// test 'string' type
assert(typeof 'foobar' == 'string');
// then that actual value '==' expected value
assert.equal('foobar', 'foobar');
// then that actual value '===' expected value
assert.strictEqual('foobar', 'foobar');

assert帮助文档： 点击打开链接

Must.js

/ test 'string' type
test.must('foobar').be.a.string();
// then that actual value '==' expected value
test.must('foobar' == 'foobar').be.true();
// then that actual value '===' expected value
test.must('foobar').be.equal('foobar');
// Must.js library (alternative style)
var must = test.must;
// test 'string' type
('foobar').must.be.a.string();
// then that actual value '==' expected value
('foobar' == 'foobar').must.be.true();
// then that actual value '===' expected value
('foobar').must.be.equal('foobar');
// this shortcut works also like this
// test 'string' type
must('foobar').be.a.string();
// then that actual value '==' expected value
must('foobar' == 'foobar').be.true();
// then that actual value '===' expected value
must('foobar').be.equal('foobar');

Must.js帮助文档： 点击打开链接

Should.js

// test 'string' type
test.should('foobar').be.type('string');
// then that actual value '==' expected value
test.should('foobar' == 'foobar').be.ok;
// then that actual value '===' expected value
test.should('foobar').be.equal('foobar');
// Should.js library (alternative style)
var should = test.should;
// test 'string' type
('foobar').should.be.type('string');
// then that actual value '==' expected value
('foobar' == 'foobar').should.be.ok;
// then that actual value '===' expected value
('foobar').should.be.equal('foobar');
// this shortcut works also like this
// test 'string' type
should('foobar').be.type('string');
// then that actual value '==' expected value
should('foobar' == 'foobar').be.ok;
// then that actual value '===' expected value
should('foobar').be.equal('foobar');

Should.js帮助文档： 点击打开链接

Sinon.js

Spy：

var spy = test.spy();
spy(42);
test.assert(spy.withArgs(42).calledOnce);

Mock：

function once(fn) {
  var
    returnValue,
    called = false
  ;
  return function () {
    if (!called) {
      called = true;
      returnValue = fn.apply(this, arguments);
    }
    return returnValue;
  };
};
var myAPI = { method: function () {} };
var mock = test.mock(myAPI);
mock
  .expects('method')
  .once()
  .returns(42)
;
var proxy = once(myAPI.method);
test.number(proxy()).is(42);
mock.verify();

Sandbox：

it('test using sandbox', test.sinon.test(function () {
  var myAPI = {
    method: function () {}
  };
  var mockMyApi = this.mock(myAPI).expects('method').once().returns(42);
  var proxy = once(myAPI.method);
  test.number(proxy()).isIdenticalTo(42);
  mockMyApi.verify();
}));

Sinon.js的帮助文档： 点击打开链接