使用NSubstitute輔助單元測試及TDD(2)

 NSubstitute   C#  

▌背景

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本篇練習NSubstitute的重點在於：

1.  在Unit Test中，如何Mock一些原始專案讀取內部資源（例如AppConfig）的方式。

2.  搭配Microsoft.VisualStudio.TestTools.UnitTesting.PrivateObject，撰寫更有效率的測試代碼。

以先前寫的WebHook程式碼，加上單元測試為例。

這個專案的其中一個類別 PostCallbackRepositor提供一個方法 ：

/// <summary> /// 取得要Post Callback的Client Uri /// <para>有效的Client Uri必須符合以下條件:</para> /// <para>1.資料庫註記IsEnabled==true</para> /// <para>2.不在Config設定的IP黑名單中</para> /// </summary> /// <returns>WebHookCallback list</returns> public IEnumerable<WebHookCallback> GetClientUris()

所以在測試這個方法時，我們至少需要利用NSubstitute建立兩個Mock objects：

l   存取資料庫

l   存取Config

以正確的測試此方法。

▌相關文章

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l   使用NSubstitute輔助單元測試及TDD(1)

l   使用NSubstitute輔助單元測試及TDD(2)

▌實作

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▋Verify the codes which you wanna test

上面提到我們要測試的程式碼如下：

public class PostCallbackRepository:IDisposable {         private IAppconfigManager appconfigManagerNsub;         private IWebHookCallbackService whCallbackServiceNsub;         public PostCallbackRepository()         {             this.appconfigManagerNsub = new AppconfigManager();             this.whCallbackServiceNsub = new WebHookCallbackService();         }         /// <summary>         /// 取得要Post Callback的Client Uri         /// <para>有效的Client Uri必須符合以下條件:</para>         /// <para>1.資料庫註記IsEnabled==true</para>         /// <para>2.不在Config設定的IP黑名單中</para>         /// </summary>         /// <returns>WebHookCallback list</returns>         public IEnumerable<WebHookCallback> GetClientUris()         {             var entities = whCallbackServiceNsub.Get(                 x => !String.IsNullOrEmpty(x.Uri) &&                 x.IsEnabled == true).ToList();             for (int i= (entities.Count-1); i>=0; i--)             {                 if(this.chkIfLockedIp(entities[i].Uri))                 {                     entities.Remove(entities[i]);                 }             }             return entities.AsEnumerable();         }         private bool chkIfLockedIp(String uri)         {             foreach(var lockedIp in appconfigManagerNsub.LockIPs)             {                 if (uri.IndexOf(lockedIp) >= 0)                      return true;             }             return false;         }         public void Dispose()         {             this.appconfigManagerNsub = null;             this.whCallbackServiceNsub = null;         } }

PS. 在讀取Config的設定值這一段，如果沒有建立一個Interface來處理，則無法使用NSubstitute來處理，這邊是比較可能需要重構的地方。

By the way, 以下是資料表結構和Config檔的參考

▋Unit Test

如前述，在測試代碼中，只要針對DAL和讀取Config的interfaces建立NSub Mock objects，並利用Microsoft.VisualStudio.TestTools.UnitTesting.PrivateObject注入， 即可順利進行測試。

相關說明可直接參考程式碼註解。

[TestMethod] public void TestTriggerCallback() {             #region Create the Substitutes             //Create the Nsubs for the interfaces             var appconfigManagerNsub = Substitute.For<IAppconfigManager>();             var whCallbackServiceNsub = Substitute.For<IWebHookCallbackService>();             #endregion             #region Set the return value of the mock objects             var mockupClientUris = new List<WebHookCallback>() {                     new WebHookCallback() { WebHookCallbackId= 1, IsEnabled=true, Uri= "http://10.1.2.3:13050/api/Receive/Receive1" },                     new WebHookCallback() { WebHookCallbackId= 2, IsEnabled=true, Uri= "http://10.4.5.6:13050/api/Receive/Receive1" },                     new WebHookCallback() { WebHookCallbackId= 3, IsEnabled=true, Uri= "http://localhost:13050/api/Receive/Receive1" },                     new WebHookCallback() { WebHookCallbackId= 4, IsEnabled=true, Uri= "http://localhost:13050/api/Receive/Receive2" },                     new WebHookCallback() { WebHookCallbackId= 5, IsEnabled=true, Uri= "http://localhost:13050/api/Receive/Receive3" },                 };                         whCallbackServiceNsub.Get( Arg.Any<Func<WebHookCallback, Boolean>>()).Returns(                 mockupClientUris.AsQueryable());             appconfigManagerNsub.LockIPs.Returns(new String[] { "10.1.2.3", "10.4.5.6" });             #endregion             #region Intialize the test target             var pcbRepository =                 new JB.Sample.WebHook.WebApi.PostCallbackRepository();             PrivateObject accessor = new PrivateObject(pcbRepository);             accessor.SetField("appconfigManagerNsub", appconfigManagerNsub);             accessor.SetField("whCallbackServiceNsub", whCallbackServiceNsub);             #endregion             #region Test Codes             IEnumerable<WebHookCallback> actualWhCallbacks = pcbRepository.GetClientUris().OrderBy(x=>x.WebHookCallbackId);             var expectedCnt = 3;             Assert.AreEqual(expectedCnt, actualWhCallbacks.Count());             Assert.AreEqual(actualWhCallbacks.ElementAt(0).Uri, mockupClientUris[2].Uri);             Assert.AreEqual(actualWhCallbacks.ElementAt(1).Uri, mockupClientUris[3].Uri);             Assert.AreEqual(actualWhCallbacks.ElementAt(2).Uri, mockupClientUris[4].Uri);             #endregion         }

測試結果 :

▌Reference

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