测试驱动开发例子学习-Using TDD with ADO.NET

来源 ：博客园 使用智能客户端 http://www.cnblogs.com/jasonw/archive/2004/10/10/50659.html

1. 连接字符串的测试驱动范例：

DataBase -SQL Server 2000:
1.Connecting to the Database
2.XML 应用程序的配置文件:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<appSettings>
<add key="Catalog.Connection"
value="server=(local);database=catalog;Trusted_Connection=true" />
</appSettings>
</configuration>

using System;

using System.Data;

using System.Data.SqlClient;

using NUnit.Framework;

[TestFixture]

public class SqlConnectionFixture

{

[Test]

public void ConnectionIsOpen()

{
// 使用配置文件定义连接字符串
//string connectionString =

// ConfigurationSettings.AppSettings.Get("Catalog.Connection");

//Assert.IsNotNull(connectionString);

SqlConnection connection =

new SqlConnection(

@"server=(local);database=catalog;Trusted_Connection=true");

connection.Open();

Assert.AreEqual(ConnectionState.Open,connection.State);

connection.Close();

}

}

2. 连接字符串的测试驱动优化范例：

以上代码可以替换为:

[TestFixture]

public class SqlConnectionFixture

{

private string connectionString;

[SetUp]

public void RetrieveConnectionString()

{

connectionString =

ConfigurationSettings.AppSettings.Get("Catalog.Connection");

}

[Test]

public void CanRetrieveConnectionString()

{

Assert.IsNotNull(connectionString);

}

[Test]

public void ConnectionIsOpen()

{

SqlConnection connection =

new SqlConnection(connectionString);

connection.Open();

Assert.AreEqual(ConnectionState.Open,connection.State);

connection.Close();

}

}

3. ArtistGateway实现数据访问层的一个范例

对数据表artist 的通用操作

using System;

using System.Data;

using System.Data.SqlClient;

namespace DataAccessLayer

{

 public class ArtistGateway

 {

 private SqlDataAdapter adapter; 

private SqlConnection connection;

 private SqlCommand command;

 private SqlCommandBuilder builder;

 public ArtistGateway(SqlConnection connection)

 {

 this.connection = connection;

 command = new SqlCommand(

 "select id,name from artist where id = @id",

 connection);

 command.Parameters.Add("@id",SqlDbType.BigInt);

 adapter = new SqlDataAdapter(command);

 builder = new SqlCommandBuilder(adapter);

 }

 public long Insert(

RecordingDataSet recordingDataSet,string artistName)

 {

 long artistId = 

GetNextId(recordingDataSet.Artists.TableName);

RecordingDataSet.Artist artistRow = 

recordingDataSet.Artists.NewArtist();

 artistRow.Id = artistId;

 artistRow.Name = artistName;

 recordingDataSet.Artists.AddArtist(artistRow);

 adapter.Update(recordingDataSet,

recordingDataSet.Artists.TableName);

 return artistId;

 }

 public RecordingDataSet.Artist 

FindById(long artistId,RecordingDataSet recordingDataSet)

 {

 command.Parameters["@id"].Value = artistId;

 adapter.Fill(recordingDataSet,

recordingDataSet.Artists.TableName);

 DataRow[] rows = recordingDataSet.Artists.Select(

 String.Format("id={0}",artistId));

if(rows.Length < 1) return null;

 return (RecordingDataSet.Artist)rows[0]; 

}

 public long GetNextId(string tableName)

 {

 SqlTransaction transaction = 

connection.BeginTransaction(

 IsolationLevel.Serializable,"GenerateId");

 SqlCommand selectCommand = new SqlCommand(

 "select nextId from PKSequence where tableName = @tableName",

connection,transaction);

 selectCommand.Parameters.Add("@tableName",

SqlDbType.VarChar).Value=tableName;

 long nextId = (long)selectCommand.ExecuteScalar();

 SqlCommand updateCommand = new SqlCommand(

 "update PKSequence set nextId = @nextId where tableName=@tableName",

 connection,transaction);

 updateCommand.Parameters.Add("@tableName",

SqlDbType.VarChar).Value=tableName;

 updateCommand.Parameters.Add("@nextId",

SqlDbType.BigInt).Value=nextId+1;

 updateCommand.ExecuteNonQuery();

 transaction.Commit();

 return nextId;

 }

4. ArtistFixture.cs 数据访问层代理类的测试用例

using System;

using System.Configuration;

using System.Data;

using System.Data.SqlClient;

using DataAccessLayer;

using NUnit.Framework;

[TestFixture]

public class ArtistFixture

{

 [Test]

 public void RetrieveArtistFromDatabase()

 {

 string artistName = "Artist";

 SqlConnection connection = 

new SqlConnection(

 ConfigurationSettings.AppSettings.Get(

"Catalog.Connection"));

 connection.Open();

 ArtistGateway gateway = new ArtistGateway(connection);

 long artistId = 

gateway.Insert(new RecordingDataSet(),artistName);

RecordingDataSet loadedFromDB = new RecordingDataSet();

 RecordingDataSet.Artist loadedArtist = 

gateway.FindById(artistId,loadedFromDB);

 Assert.AreEqual(artistId,loadedArtist.Id);

 Assert.AreEqual(artistName,loadedArtist.Name);

 gateway.Delete(loadedFromDB,artistId); //删除功能的驱动

connection.Close();

 }

}

5. 删除驱动所形成的实现代码：

public void Delete(RecordingDataSet recordingDataSet,long artistId)

{

RecordingDataSet.Artist loadedArtist =

FindById(artistId,recordingDataSet);

loadedArtist.Delete();

adapter.Update(recordingDataSet,

recordingDataSet.Artists.TableName);

}

6. 有了完整的测试用例，以及实现的代码，可以进行重构：

//首先优化测试的代码：

[TestFixture]

public class ArtistFixture

{

 private static readonly string artistName = "Artist";

 private SqlConnection connection;

 private ArtistGateway gateway; 

private RecordingDataSet recordingDataSet;

 private long artistId; 

 [SetUp]

 public void SetUp()

 {

 connection = new SqlConnection(

 ConfigurationSettings.AppSettings.Get(

 "Catalog.Connection"));

 connection.Open();

 recordingDataSet = new RecordingDataSet();

 gateway = new ArtistGateway(connection);

 artistId = gateway.Insert(recordingDataSet,artistName);

 }

 [TearDown]

 public void TearDown()

 {

 gateway.Delete(recordingDataSet,artistId);

 connection.Close();

 }

 [Test]

 public void RetrieveArtistFromDatabase()

 {

 RecordingDataSet loadedFromDB = new RecordingDataSet();

 RecordingDataSet.Artist loadedArtist = 

gateway.FindById(artistId,loadedArtist.Name); 

}

 [Test]

 public void DeleteArtistFromDatabase()

 {

 RecordingDataSet emptyDataSet = new RecordingDataSet();

 long deletedArtistId = gateway.Insert(emptyDataSet,"Deleted Artist");

 gateway.Delete(emptyDataSet,deletedArtistId);

 RecordingDataSet.Artist deleletedArtist = 

gateway.FindById(deletedArtistId,emptyDataSet);

 Assert.IsNull(deleletedArtist);

 }

}

7. 在重构的基础上加入更新方法：.

[Test]

public void UpdateArtistInDatabase()

{

 RecordingDataSet.Artist artist = recordingDataSet.Artists[0];

 artist.Name = "Modified Name";

 gateway.Update(recordingDataSet);

 RecordingDataSet updatedDataSet = new RecordingDataSet();

 RecordingDataSet.Artist updatedArtist = 

gateway.FindById(artistId,updatedDataSet);

 Assert.AreEqual("Modified Name",updatedArtist.Name);

}

//The following is the implementation of Update:

 public void Update(RecordingDataSet recordingDataSet)

 {

 adapter.Update(recordingDataSet,

 recordingDataSet.Artists.TableName);

 }

8. Genre Gateway 另一个测试驱动的例子（类似于artists）

[TestFixture]

public class GenreFixture

{

 private static readonly string genreName = "Rock";

 private SqlConnection connection;

 private GenreGateway gateway; 

private RecordingDataSet recordingDataSet;

 private long genreId; 

 [SetUp]

 public void SetUp()

 {

 connection = new SqlConnection(

 ConfigurationSettings.AppSettings.Get(

 "Catalog.Connection"));

 connection.Open();

 recordingDataSet = new RecordingDataSet();

 gateway = new GenreGateway(connection);

 genreId = gateway.Insert(recordingDataSet,genreName);

 }

 [TearDown]

 public void TearDown()

 {

 gateway.Delete(recordingDataSet,genreId);

 connection.Close();

 }

 [Test]

 public void RetrieveGenreFromDatabase()

 {

 RecordingDataSet loadedFromDB = new RecordingDataSet();

 RecordingDataSet.Genre loadedGenre = 

gateway.FindById(genreId,loadedFromDB);

 Assert.AreEqual(genreId,loadedGenre.Id);

 Assert.AreEqual(genreName,loadedGenre.Name); 

}

}

9. 实现部分Genre Gateway：

public class GenreGateway

 {

 private SqlDataAdapter adapter; 

private SqlConnection connection;

 private SqlCommand command;

 private SqlCommandBuilder builder;

 public GenreGateway(SqlConnection connection)

 {

 this.connection = connection;

 command = new SqlCommand(

 "select id,name from Genre where id = @id",SqlDbType.BigInt);

 adapter = new SqlDataAdapter(command);

 builder = new SqlCommandBuilder(adapter);

 }

 public long Insert(RecordingDataSet recordingDataSet,

string genreName)

 {

 long genreId = GetNextId(recordingDataSet.Genres.TableName);

RecordingDataSet.Genre genreRow = 

recordingDataSet.Genres.NewGenre();

 genreRow.Id = genreId;

 genreRow.Name = genreName;

 recordingDataSet.Genres.AddGenre(genreRow);

 adapter.Update(recordingDataSet,

recordingDataSet.Genres.TableName);

 return genreId;

 }

 public RecordingDataSet.Genre 

FindById(long genreId,RecordingDataSet recordingDataSet)

 {

 command.Parameters["@id"].Value = genreId;

 adapter.Fill(recordingDataSet,

recordingDataSet.Genres.TableName);

 DataRow[] rows = recordingDataSet.Genres.Select(

 String.Format("id={0}",genreId));

if(rows.Length < 1) return null;

 return (RecordingDataSet.Genre)rows[0];

 }

 public void Delete(RecordingDataSet recordingDataSet,

long genreId)

 {

 RecordingDataSet.Genre loadedGenre = 

FindById(genreId,recordingDataSet);

 loadedGenre.Delete();

 adapter.Update(recordingDataSet,

recordingDataSet.Genres.TableName);

 }

 public long GetNextId(string tableName)

 { /* same as in ArtistGateway */ }

 }

10.获取下一个ID

[TestFixture]

public class IdGeneratorFixture

{

 private SqlConnection connection;

 [SetUp]

 public void OpenConnection()

 {

 connection = new SqlConnection(

 ConfigurationSettings.AppSettings.Get(

 "Catalog.Connection"));

 connection.Open();

 }

 [Test]

 public void GetNextIdIncrement()

 {

 SqlCommand sqlCommand = new SqlCommand(

 "select nextId from PKSequence where tableName=@tableName",

 connection);

sqlCommand.Parameters.Add(

 "@tableName",SqlDbType.VarChar).Value="Artist";

long nextId = (long)sqlCommand.ExecuteScalar();

 long nextIdFromGenerator = 

IdGenerator.GetNextId("Artist",connection);

 Assert.AreEqual(nextId,nextIdFromGenerator);

 nextId = (long)sqlCommand.ExecuteScalar();

 Assert.AreEqual(nextId,nextIdFromGenerator + 1);

 }

 [TearDown]

 public void CloseConnection()

 {

 connection.Close();

 }

}

//实现部分

public class IdGenerator

{

 public static long GetNextId(string tableName,

SqlConnection connection)

 {

 SqlTransaction transaction = connection.BeginTransaction(

IsolationLevel.Serializable,"GenerateId");

 SqlCommand selectCommand = new SqlCommand(

 "select nextId from PKSequence where tableName = @tableName",

 SqlDbType.VarChar).Value=tableName;

 long nextId = (long)selectCommand.ExecuteScalar();

 SqlCommand updateCommand = new SqlCommand(

 "update PKSequence set nextId = @nextId where tableName=@tableName",SqlDbType.VarChar).Value=tableName;

 updateCommand.Parameters.Add("@nextId",SqlDbType.BigInt).Value=nextId+1;

 updateCommand.ExecuteNonQuery();

 transaction.Commit();

 return nextId;

 }

}

11.IdGeneratorFixture.cs优化过得实现：

using System;

using System.Configuration;

using System.Data;

using System.Data.SqlClient;

using NUnit.Framework;

using DataAccessLayer;

[TestFixture]

public class IdGeneratorFixture : ConnectionFixture

{

 [Test]

 public void GetNextIdIncrement()

 {

 SqlCommand sqlCommand = 

new SqlCommand(

 "select nextId from PKSequence where tableName=@tableName",

 Connection);

 sqlCommand.Parameters.Add("@tableName",SqlDbType.VarChar).Value="Artist";

long nextId = (long)sqlCommand.ExecuteScalar();

 long nextIdFromGenerator = IdGenerator.GetNextId("Artist",Connection);

 Assert.AreEqual(nextId,nextIdFromGenerator + 1);

 }

}