C# NUnit TestCaseSource Passing Parameter

Question

I have the following method which generates a set of test cases!

public IEnumerable PrepareTestCases(param1)
{
    foreach (string e         


        

Answer 1

In my case I would like to load data from a CSV file but I couldn't pass the filename to the "datasource". After struggling a bit around I come to this two cent solution.

At first I inherited TestCaseSourceAttirbute

/// 

/// FactoryAttribute indicates the source to be used to provide test cases for a test method.
/// 
[AttributeUsage(AttributeTargets.Method, AllowMultiple = false, Inherited = true)]
public class TestCaseCsvAttribute : TestCaseSourceAttribute 
{
    public TestCaseCsvAttribute(Type mapped, Type config) : base(typeof(TestCsvReader<,>).MakeGenericType(mapped, config), "Data")
    { }
}

then I created the data layer, in my case a CSV reader.

    /// 

    /// Test data provider
    /// 
    /// Type to return in enumerable
    /// Configuration type that provide Filenames
    public sealed class TestCsvReader
    {
        /// 

        /// Initializes a new instance of the  class.
        /// 
        public TestCsvReader()
        {
            this.Config = (C)Activator.CreateInstance();
        }

        /// 

        /// Gets or sets the configuration.
        /// 
        /// 
        /// The configuration.
        /// 
        private C Config { get; set; }

        /// 

        /// Gets the filename.
        /// 
        /// 
        /// The filename.
        /// 
        /// 
        /// 
        private string Filename
        {
            get
            {
                try
                {
                    string result = Convert.ToString(typeof(C).GetProperty(string.Format("{0}Filename", typeof(T).Name)).GetValue(this.Config));
                    if (!File.Exists(result))
                        throw new Exception(string.Format("Unable to find file '{0}' specified in property '{1}Filename' in class '{1}'", result, typeof(C).Name));

                    return result;
                }
                catch
                {
                    throw new Exception(string.Format("Unable to find property '{0}Filename' in class '{1}'", typeof(T).Name, typeof(C).Name));
                }
            }
        }

        /// 

        /// Yields values from source
        /// 
        /// 
        public IEnumerable Data()
        {
            string file = this.Filename;

            T[] result = null;
            using (StreamReader reader = File.OpenText(file))
            {
                //TODO: do it here your magic
            }
            yield return new TestCaseData(result);
        }
}

Then I created a class with the only scope to contain properties with the file paths. There's a name convention about the property, that's ClassTypeName + "Filename".

public class Configurations
{
    public string ConflictDataFilename
    {
        get
        {
            return @"C:\test.csv";
        }
    }
}

At this point just decorate accordingly the test, with the type of class to map to data and the class that contain file path.

[Test(Description="Try this one")]
[TestCaseCsv(typeof(ClassMappedToData), typeof(Configurations))]
public void Infinite(ClassMappedToData[] data)
{
}

Hope this can help a bit.