Walkthrough: Using a Configuration File to Define a Data Source
This walkthrough shows how to use a data source defined in an app.config file for unit testing. You will learn how to create an app.config file that defines a data source that can be used by the DataSourceAttribute class. Tasks presented in this walkthrough include the following:
Creating an app.config file.
Defining a custom configuration section.
Defining connection strings.
Defining the data sources.
Accessing the data sources by using the DataSourceAttribute class.
To complete this walkthrough, you will need:
Visual Studio Team System Test Edition
Either Microsoft Access or Microsoft Excel to provide data for at least one of the test methods.
A Visual Studio 2005 solution that contains a test project.
If your test project already has an app.config file, go to Define a Custom Configuration Section.
Right-click your test project in Solution Explorer, point to Add, and then click New Item.
The Add New Item window opens.
Select the Application Configuration File template and click Add.
Examine the app.config file. It contains at least the XML declaration and a root element.
The root element of app.config should be the configuration element. Create a configSections element within the configuration element. The configSections should be the first element in the app.config file.
Within the configSections element, create a section element.
In the section element, add an attribute called name and assign it a value equal microsoft.visualstudio.testtools. Add another attribute called type and assign it a value equal Microsoft.VisualStudio.TestTools.UnitTesting.TestConfigurationSection, Microsoft.VisualStudio.QualityTools.UnitTestFramework, Version=9.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
The section element should resemble this:
<section name="microsoft.visualstudio.testtools" type="Microsoft.VisualStudio.TestTools.UnitTesting.TestConfigurationSection, Microsoft.VisualStudio.QualityTools.UnitTestFramework, Version=9.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"/>
Anteckning
The assembly name must match the Microsoft Visual Studio .NET Framework build that you are using. Set the Version to 9.0.0.0 if you are using the Visual Studio .NET Framework 3.5. If you are using the Visual Studio .NET Framework 2.0, set the Version to 8.0.0.0.
The connection strings define provider specific information for accessing data sources. Connection strings that are defined in configuration files provide reusable data provider information across an application. In this section, you create two connection strings that will be used by data sources that are defined in the Custom Configuration Section.
After the configSections element, create a connectionStrings element.
Within the connectionStrings element, create two add elements.
In the first add element, create the following attributes and values for a connection to a Microsoft Access database:
Attribute |
Values |
---|---|
name |
"MyJetConn" |
connectionString |
"Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\testdatasource.accdb; Persist Security Info=False;" |
providerName |
"System.Data.OleDb" |
In the second add element, create the following attributes and values for a connection to a Microsoft Excel spreadsheet:
name |
"MyExcelConn" |
connectionString |
"Dsn=Excel Files;dbq=data.xlsx;defaultdir=.; driverid=790;maxbuffersize=2048;pagetimeout=5" |
providerName |
"System.Data.Odbc" |
The connectionStrings element should resemble this:
<connectionStrings>
<add name="MyJetConn" connectionString="Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\testdatasource.accdb; Persist Security Info=False;" providerName="System.Data.OleDb" />
<add name="MyExcelConn" connectionString="Dsn=Excel Files;dbq=data.xlsx;defaultdir=.; driverid=790;maxbuffersize=2048;pagetimeout=5" providerName="System.Data.Odbc" />
</connectionStrings>
The data sources section contains four attributes that are used by the test engine to retrieve data from a data source.
name defines the identity used by the DataSourceAttribute to specify which data source to use.
connectionString identifies the connection string created in the previous Define Connection Strings section.
dataTableName defines the table or sheet that holds the data to use in the test.
dataAccessMethod defines the technique for accessing data values in the data source.
In this section, you will define two data sources to use in a unit test.
After the connectionStrings element, create a microsoft.visualstudio.testtools element. This section was created in Define a Custom Configuration Section.
Within the microsoft.visualstudio.testtools element, create a dataSources element.
Within the dataSources element, create two add elements.
In the first add element, create the following attributes and values for a Microsoft Access data source:
Attribute |
Values |
---|---|
name |
"MyJetDataSource" |
connectionString |
"MyJetConn" |
dataTableName |
"MyDataTable" |
dataAccessMethod |
"Sequential" |
In the second add element, create the following attributes and values for a Microsoft Excel data source:
Name |
"MyExcelDataSource" |
connectionString |
"MyExcelConn" |
dataTableName |
"Sheet1$" |
dataAccessMethod |
"Sequential" |
The microsoft.visualstudio.testtools element should resemble this:
<microsoft.visualstudio.testtools>
<dataSources>
<add name="MyJetDataSource" connectionString="MyJetConn" dataTableName="MyDataTable" dataAccessMethod="Sequential"/>
<add name="MyExcelDataSource" connectionString="MyExcelConn" dataTableName="Sheet1$" dataAccessMethod="Sequential"/>
</dataSources>
</microsoft.visualstudio.testtools>
The final app.config file should resemble this:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<configSections>
<section name="microsoft.visualstudio.testtools" type="Microsoft.VisualStudio.TestTools.UnitTesting.TestConfigurationSection, Microsoft.VisualStudio.QualityTools.UnitTestFramework, Version=8.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"/>
</configSections>
<connectionStrings>
<add name="MyJetConn" connectionString="Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\testdatasource.accdb; Persist Security Info=False;" providerName="System.Data.OleDb" />
<add name="MyExcelConn" connectionString="Dsn=Excel Files;dbq=data.xlsx;defaultdir=.; driverid=790;maxbuffersize=2048;pagetimeout=5" providerName="System.Data.Odbc" />
</connectionStrings>
<microsoft.visualstudio.testtools>
<dataSources>
<add name="MyJetDataSource" connectionString="MyJetConn" dataTableName="MyDataTable" dataAccessMethod="Sequential"/>
<add name="MyExcelDataSource" connectionString="MyExcelConn" dataTableName="Sheet1$" dataAccessMethod="Sequential"/>
</dataSources>
</microsoft.visualstudio.testtools>
</configuration>
Now that an app.config file has been defined, you will create a unit test that uses data located in the data sources that are defined in the app.config file. In this section, we will:
Create the data sources found in the app.config file.
Use the data sources in two test methods that compare the values in each data source.
Create a Microsoft Access database named testdatasource.accdb.
Create a table and name it MyDataTable in testdatasource.accdb.
Create two fields in MyDataTable named Arg1 and Arg2 using the Number data type.
Add five entities to MyDataTable with the following values for Arg1 and Arg2, respectively: (10,50), (3,2), (6,0), (0,8) and (12312,1000).
Save and close the database.
In the app.config file, change the connection string to point to the location of the database. Change the value of Data Source to reflect the location of the database.
Create a Microsoft Excel spreadsheet named data.xlsx.
Create a sheet named Sheet1 if it does not already exist in data.xlsx.
Create two column headers and name them Val1 and Val2 in Sheet1.
Add five entities to Sheet1 with the following values for Val1 and Val2, respectively: (1,1), (2,2), (3,3), (4,4) and (5,0).
Save and close the spreadsheet.
In the app.config file, change the connection string to point to the location of the spreadsheet. Change the value of dbq to reflect the location of the spreadsheet.
Add a unit test to the test project.
Replace the auto-generated contents of the unit test with the following code:
using System; using Microsoft.VisualStudio.TestTools.UnitTesting; namespace TestProject1 { [TestClass] public class UnitTest1 { private TestContext context; public TestContext TestContext { get { return context; } set { context = value; } } [TestMethod()] [DeploymentItem("MyTestProject\\testdatasource.accdb")] [DataSource("MyJetDataSource")] public void MyTestMethod() { int a = Int32.Parse(context.DataRow["Arg1"].ToString()); int b = Int32.Parse(context.DataRow["Arg2"].ToString()); Assert.AreNotEqual(a, b, "A value was equal."); } [TestMethod()] [DeploymentItem("MyTestProject\\data.xlsx")] [DataSource("MyExcelDataSource")] public void MyTestMethod2() { Assert.AreEqual(context.DataRow["Val1"], context.DataRow["Val2"]); } } }
Examine the DataSource attributes. Notice the setting names from the app.config file.
Build your solution and run MyTestMethod and MyTestMethod2 tests.
Important Note: |
---|
Deploy items like data sources so that they are available to the test in the deployment directory. For more information, see Test Deployment. |
How to: Create and Run a Unit Test