桩对象（三）

待我称王封你为后i 2022-04-10 13:25 170阅读 0赞

在上篇文章中，桩对象是由外部代码在测试开始之前设置。本文将通过工厂类，在被测代码内容初始化桩对象。

## 1.被测类 ##

public class LogAnalyzer
    {
        private const int minFileNameLength = 6;
        private IExtensionManager manager;
    
        //使用工厂
        public LogAnalyzer()
        {
            manager = ExtensionManagerFactory.Create();
        }
    
        //支持文件类型及文件名是否足够长
        public bool IsValidLogFileName(string fileName)
        {
                return manager.IsValid(fileName) && Path.GetFileNameWithoutExtension(fileName).Length > minFileNameLength;        
        }
    }

##  2.工厂类 ##

static public class ExtensionManagerFactory
    {
        static private IExtensionManager customManager = null;
    
        static public IExtensionManager Create()
        {
            if (customManager != null)
                return customManager;
            return new FileExtensionManager();
        }
    
        static public void SetManager(IExtensionManager mgr)
        {
            customManager = mgr;
        }
    }

## 3.测试类 ##

[TestFixture]
    public class LogAnalyzerTests
    {       
        [Test]
        public void IsValidLogFileName_NameShorterThan6charsButSupportedExtension_ReturnFalse()
        {
            //创建桩对象
            StubExtensionManager fakeManager = new StubExtensionManager();
            fakeManager.ShouldExtensionBeValid = true;
    
            //将桩对象赋给工厂类
            ExtensionManagerFactory.SetManager(fakeManager);
            //新建analyzer并注入桩对象
            LogAnalyzer analyzer = new LogAnalyzer();
            
            bool result = analyzer.IsValidLogFileName("s.log");
            Assert.IsFalse(result, "File name with less than 5 chars should have failed the method, even if the extension is supported.");
        }    
    }