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         


        

Answer 1

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.

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"];