How to use web.config when unit testing an asp .net application

Question

I am starting out with unit testing, I have a method that uses the web.config for a connection string.

I was hoping to be able to use

[DeploymentItem("web.config")] 

to get the web config file, this still leaves me with null reference exceptions (that'd be what I write my next test for).

How do I use the config file included with the project I am trying to test?

I am using the testing framework included in VS 2008, if that makes any difference.

Thanks

Answer 1

Unit test projects should have their own config file.

On a test project you can choose Add, New Item, Application Configuration File.

This file will behave exactly like a web.config, but then for your unit tests.

Answer 2

You can load in a web.config or app.config from any location using OpenMappedExeConfiguration. Make sure System.Configuration is added to your project's References.

ExeConfigurationFileMap fileMap = new ExeConfigurationFileMap() fileMap.ExeConfigFilename = @"c:\my-web-app-location\web.config"  Configuration config = ConfigurationManager.OpenMappedExeConfiguration(fileMap, ConfigurationUserLevel.None); string connectionString = config.AppSettings.Settings["ConnectionString"].Value; 

Here is the web.config, pretty standard.

<?xml version="1.0"?> <configuration>   <configSections>   </configSections>   <appSettings>     <add key="ConnectionString" value="Data Source=XXXX;Initial Catalog=XXX; Trusted_Connection=True;"/>   </appSettings> </configuration> 

Update on 2017-09-29

I have come up a class to make it easier for reading AppSetitngs from file. I got the idea from Zp Bappi.

public interface IAppSettings {     string this[string key] { get; } }  public class AppSettingsFromFile : IAppSettings {     readonly Configuration Config;      public AppSettingsFromFile(string path)     {         var fileMap = new ExeConfigurationFileMap();         fileMap.ExeConfigFilename = path;         Config = ConfigurationManager.OpenMappedExeConfiguration(fileMap, ConfigurationUserLevel.None);     }      public string this[string key]     {         get         {             return Config.AppSettings.Settings[key].Value;         }     } } 

Here is how to use the class.

IAppSettings AppSettings = new AppSettingsFromFile(@"c:\my-web-app-location\web.confg"); string connectionString = AppSettings["ConnectionString"];