Is it bad to add code just for unit testing? [closed]

Question

I am writing a class to help me unit test my code. It looks like this:

/// <summary>
/// Wrapper for the LogManager class to allow us to stub the logger
/// </summary>
public class Logger
{
    private static ILogger _logger = null;

    /// <summary>
    /// This should be called to get a valid logger.
    /// </summary>
    /// <returns>A valid logger to log issues to file.</returns>
    public static ILogger GetLogger()
    {
        if (_logger == null)
          _logger = LogManager.GetLogger("logger");

        return _logger;
    }

    /// <summary>
    /// This is used by unit tests to allow a stub to be used as a logger.
    /// </summary>
    /// <param name="logger"></param>
    /// <returns></returns>
    public static ILogger GetLogger(ILogger logger)
    {
        _logger = logger;
        return _logger;
    }
}

The second method is for unit testing only. I never intend to have it called in my production code.

Is this bad practice? Should I find another way that does not do this?

Answer 1

In my opinion yes, this is a bad practice. Unit testing is meant to test implementation of your code, not really to influence it. In some cases I've found it practical to organize my code/methods in a manner to make it more easily/thoroughly tested, but writing code in a class being tested for specific use in testing is a different story.