How to throw a SqlException when needed for mocking and unit testing?

Question

I am trying to test some exceptions in my project and one of the Exceptions I catch is SQlException.

It seems that you can\'t go new SqlException(

Answer 1

I suggest using this method.

    /// 

    /// Method to simulate a throw SqlException
    /// 
    /// Exception number
    /// Exception message
    /// 
    public static SqlException CreateSqlException(int number, string message)
    {
        var collectionConstructor = typeof(SqlErrorCollection)
            .GetConstructor(BindingFlags.NonPublic | BindingFlags.Instance, //visibility
                null, //binder
                new Type[0],
                null);
        var addMethod = typeof(SqlErrorCollection).GetMethod("Add", BindingFlags.NonPublic | BindingFlags.Instance);
        var errorCollection = (SqlErrorCollection)collectionConstructor.Invoke(null);
        var errorConstructor = typeof(SqlError).GetConstructor(BindingFlags.NonPublic | BindingFlags.Instance, null,
            new[]
            {
                typeof (int), typeof (byte), typeof (byte), typeof (string), typeof(string), typeof (string),
                typeof (int), typeof (uint)
            }, null);
        var error =
            errorConstructor.Invoke(new object[] { number, (byte)0, (byte)0, "server", "errMsg", "proccedure", 100, (uint)0 });
        addMethod.Invoke(errorCollection, new[] { error });
        var constructor = typeof(SqlException)
            .GetConstructor(BindingFlags.NonPublic | BindingFlags.Instance, //visibility
                null, //binder
                new[] { typeof(string), typeof(SqlErrorCollection), typeof(Exception), typeof(Guid) },
                null); //param modifiers
        return (SqlException)constructor.Invoke(new object[] { message, errorCollection, new DataException(), Guid.NewGuid() });
    }