解決的問題：方法內部new的對象在測試時希望能夠用mock對象去代替。

問題：以下方法可以解決，但是很是丑陋，各位大俠是否有更好的方法？

描述：如果說把內部的方法放到類的一個公開成員變量，或者放到方法的參數里，我的意見是公開了不應該公開的東西。

使用第三方的類庫: Mock工具 Rhino.Mocks， IOC: Castle.Windsor

1. 現在我又這么一段代碼,我想測試Math內部這兩個方法

????public??class?Math

??? {

????????public?long?MathAdd(int?a,?int?b)

??????? {

????????????Calc?c =?new?Calc();???????????

????????????return?c.Add(a, b);

??????? }

?

????????public?long?MathAdd2Price(int?a)

??????? {

????????????Calc?c =?new?Calc();

????????????return?c.AddCount(a) + c.count;

??????? }

??? }

?

????public?class?Calc

??? {

????????public?int?count = 0;

????????public?long?Add(int?a,?int?b)

??????? {

????????????return?a + b;

??????? }

?

????????public?long?AddCount(int?num)

??????? {

????????????return?count + num;

??????? }

??? }

?

2. 我們看到，由于是在內部new的對象，我們就對Calc類產生了很大的依賴，于是我想到注入一個對像，下面是我的設計

?

?? public?class?ContainerFactory

??? {

????????public static?IWindsorContainer?container;

????????public?bool?IsDebug =?false;

????????private?static?readonly?ContainerFactory?instance =?new?ContainerFactory();

?

????????public?static?ContainerFactory?Instance

??????? {

????????????get

??????????? {

????????????????return?instance;

??????????? }

??????? }

?

????????private?ContainerFactory()

??????? {

??????????? AddAllCompent();

??????? }

?

????????private?void?AddAllCompent()

??????? {

????????????if?(container ==?null)

??????????? {

??????????????? container =?new?WindsorContainer();

????????????????//此處職位演示，未使用接口

??????????????? container.AddComponentWithLifestyle<Calc>("Calc",?LifestyleType.Transient);??????????? }

??????? }

}

這樣我們的Math類可改成這樣

??public??class?Math

??? {

????????public?long?MathAdd(int?a,?int?b)

??????? {

???????????// Calc c = new Calc();

????????????Calc?c =(Calc)?ContainerFactory.container["Calc"];

????????????return?c.Add(a, b);

??????? }

?

????????public?long?MathAdd2Price(int?a)

??????? {

????????????Calc?c = (Calc)ContainerFactory.container["Calc"];

????????????return?c.AddCount(a) + c.count;

??????? }

?

??? }

?

3.? 但是，我們如何在測試中用我們Mock的對象代替真實的對象呢？下面是我想的一個自己也認為不好的方法，但能湊活著用

?public?class?ContainerFactory

??? {

????????private?IWindsorContainer?container;

????????public?bool?IsDebug =?false;

????????private?static?readonly?ContainerFactory?instance =?new?ContainerFactory();

?

????????public?static?ContainerFactory?Instance

??????? {

????????????get

??????????? {

????????????????return?instance;

??????????? }

??????? }

?

????????private?ContainerFactory()

??????? {

??????????? AddAllCompent();

??????? }

?

????????private?void?AddAllCompent()

??????? {

????????????if?(container ==?null)

??????????? {

??????????????? container =?new?WindsorContainer();

????????????????//此處職位演示，未使用接口

??????????????? container.AddComponentWithLifestyle<Calc>("Calc",?LifestyleType.Transient);??????????? }

??????? }

?

??????? #region?Calc

????????private?Calc?DebugCalc;

????????public?Calc??? Calc

??????? {

????????????get

??????????? {

????????????????if?(IsDebug && DebugCalc !=?null)

??????????????? {

????????????????????return?DebugCalc;

??????????????? }

????????????????else

??????????????? {

????????????????????return?(Calc)container["Calc"];

??????????????? }

??????????? }

????????????set

??????????? {

????????????????// just for test, for mock object

????????????????if?(IsDebug)

??????????????? {

??????????????????? DebugCalc =?value;

??????????????? }

????????????????else

??????????????? {

????????????????????throw?new?Exception("just for test");

??????????????? }

??????????? }

??????? }

??????? #endregion?

??? }

修改我們的類

??public??class?Math

??? {

????????public?long?MathAdd(int?a,?int?b)

??????? {

???????????// Calc c = new Calc();

????????????Calc?c =?ContainerFactory.Instance.Calc;

????????????return?c.Add(a, b);

??????? }

?

????????public?long?MathAdd2Price(int?a)

??????? {

????????????Calc?c =?ContainerFactory.Instance.Calc;

????????????return?c.AddCount(a) + c.count;

??????? }

?

??? }

?

這樣我們來看我們通過了測試的代碼

[TestClass()]

????public?class?MathTest

??? {

??????? [TestMethod()]

????????public?void?MathAddTest()

??????? {

????????????Math?m =?new?Math();

?

????????????// 想讓真實代碼內部，使用的是Mock的對象

????????????// Arrange

????????????MockRepository?mocks =?new?MockRepository();

????????????Calc?mockCalc = mocks.Stub<Calc>();

??????????? mockCalc.count = 5;

????????????ContainerFactory.Instance.IsDebug =?true; //這句很重要

????????????ContainerFactory.Instance.Calc = mockCalc;

?

??????????? mocks.ReplayAll();

????????????// Act

????????????Assert.AreEqual(m.MathAdd(5, 5), 10);

????????????Assert.AreEqual(mockCalc.AddCount(6), 11);

??????????? mocks.VerifyAll();

?

????????????Calc?mockCalc2 = mocks.Stub<Calc>();

??????????? mocks.ReplayAll();

?

????????????// 這里有問題，我們希望他是7,但實際是12，因為需要測試中的和實際代碼用同一個對象，

????????????// 他保留上次的狀態count的值5

????????????Assert.AreEqual(mockCalc.AddCount(7), 12);

??????????? mocks.VerifyAll();???????????

??????? }

?

??????? [TestMethod]

????public?void?MathAddTestActual()

??? {

????????????//這里測試實際使用代碼，沒用Mock

????????Math?m =?new?Math();

????????Assert.AreEqual(m.MathAdd(5,6), 11);

????????Assert.AreEqual(m.MathAdd2Price(9), 9);

????????Calc?c =?ContainerFactory.Instance.Calc;

????????Assert.AreEqual(c.AddCount(5), 5);

??????? c.count = 20;

????????Assert.AreEqual(c.AddCount(5), 25);

????????Calc?d =?ContainerFactory.Instance.Calc;

????????Assert.AreEqual(d.AddCount(30), 30);

????????Assert.AreEqual(c.count, 20);

????????Assert.AreEqual(d.count, 0);

??? }

??? }

?

?

總結：這樣可以不使用用public的類成員變量，不用通過方法參數注入注入對象

?

問題:? ContainerFactory代碼較多，測試時需要設標志。

?

其它的問題： 等待高人指出，謝謝！

本文轉自敏捷的水博客園博客，原文鏈接http://www.cnblogs.com/cnblogsfans/archive/2008/12/16/1355640.html如需轉載請自行聯系原作者

王德水

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