Catel - Part 4 of n: Unit testing with Catel

// --------------------------------------------------------------------------------------------------------------------
// <copyright file="ExceptionExtensions.cs" company="Catel development team">
//   Copyright (c) 2008 - 2011 Catel development team. All rights reserved.
// </copyright>
// <summary>
//   Exception helper class.
// </summary>
// --------------------------------------------------------------------------------------------------------------------

using System;
using System.Diagnostics;
using System.Globalization;

namespace Catel.Diagnostics
{
    /// <summary>
    /// Exception helper class.
    /// </summary>
    public static class ExceptionExtensions
    {
        /// <summary>
        /// Traces an error message with exception details.
        /// </summary>
        /// <param name="ex"><see cref="Exception"/> that contains the additional information.</param>
        /// <param name="message">Message of the trace.</param>
        public static void TraceExceptionAsError(this Exception ex, string message)
        {
            TraceException(ex, TraceLevel.Error, message, new object[] { });
        }

        /// <summary>
        /// Traces an error message with exception details.
        /// </summary>
        /// <param name="ex"><see cref="Exception"/> that contains the additional information.</param>
        /// <param name="format">A format string that contains zero or more format items, which correspond to objects in the args array.</param>
        /// <param name="args">An object array containing zero or more objects to format.</param>
        public static void TraceExceptionAsError(this Exception ex, string format, params object[] args)
        {
            TraceException(ex, TraceLevel.Error, format, args);
        }

        /// <summary>
        /// Traces a warning message with exception details.
        /// </summary>
        /// <param name="ex"><see cref="Exception"/> that contains the additional information.</param>
        /// <param name="message">Message of the trace.</param>
        public static void TraceExceptionAsWarning(this Exception ex, string message)
        {
            TraceException(ex, TraceLevel.Warning, message, new object[] { });
        }

        /// <summary>
        /// Traces a warning message with exception details.
        /// </summary>
        /// <param name="ex"><see cref="Exception"/> that contains the additional information.</param>
        /// <param name="format">A format string that contains zero or more format items, which correspond to objects in the args array.</param>
        /// <param name="args">An object array containing zero or more objects to format.</param>
        public static void TraceExceptionAsWarning(this Exception ex, string format, params object[] args)
        {
            TraceException(ex, TraceLevel.Warning, format, args);
        }

        /// <summary>
        /// Traces an information message with exception details.
        /// </summary>
        /// <param name="ex"><see cref="Exception"/> that contains the additional information.</param>
        /// <param name="message">Message of the trace.</param>
        public static void TraceExceptionAsInformation(this Exception ex, string message)
        {
            TraceException(ex, TraceLevel.Info, message, new object[] { });
        }

        /// <summary>
        /// Traces an information message with exception details.
        /// </summary>
        /// <param name="ex"><see cref="Exception"/> that contains the additional information.</param>
        /// <param name="format">A format string that contains zero or more format items, which correspond to objects in the args array.</param>
        /// <param name="args">An object array containing zero or more objects to format.</param>
        public static void TraceExceptionAsInformation(this Exception ex, string format, params object[] args)
        {
            TraceException(ex, TraceLevel.Info, format, args);
        }

        /// <summary>
        /// Traces a verbose message with exception details.
        /// </summary>
        /// <param name="ex"><see cref="Exception"/> that contains the additional information.</param>
        /// <param name="message">Message of the trace.</param>
        public static void TraceExceptionAsVerbose(this Exception ex, string message)
        {
            TraceException(ex, TraceLevel.Verbose, message, new object[] { });
        }

        /// <summary>
        /// Traces a verbose message with exception details.
        /// </summary>
        /// <param name="ex"><see cref="Exception"/> that contains the additional information.</param>
        /// <param name="format">A format string that contains zero or more format items, which correspond to objects in the args array.</param>
        /// <param name="args">An object array containing zero or more objects to format.</param>
        public static void TraceExceptionAsVerbose(this Exception ex, string format, params object[] args)
        {
            TraceException(ex, TraceLevel.Verbose, format, args);
        }

        /// <summary>
        /// Traces a message with exception details.
        /// </summary>
        /// <param name="ex"><see cref="Exception"/> that contains the additional information.</param>
        /// <param name="level"><see cref="TraceLevel"/> to write.</param>
        /// <param name="message">Message of the trace.</param>
        public static void TraceException(this Exception ex, TraceLevel level, string message)
        {
            TraceException(ex, level, message, new object[] { });
        }

        /// <summary>
        /// Traces a message with exception details.
        /// </summary>
        /// <param name="ex"><see cref="Exception"/> that contains the additional information.</param>
        /// <param name="level"><see cref="TraceLevel"/> to write.</param>
        /// <param name="format">A format string that contains zero or more format items, which correspond to objects in the args array.</param>
        /// <param name="args">An object array containing zero or more objects to format.</param>
        public static void TraceException(this Exception ex, TraceLevel level, string format, params object[] args)
        {
            string message = (args.Length == 0) ? format : string.Format(CultureInfo.CurrentUICulture, format, args);
            string deepestExceptionMessage = ex.InnerException != null ? GetInnerException(ex).Message : "null";
            string finalMessage = string.Format("{0}  -------------> (Details: '{1}' | InnerException: {2})", message, ex.Message, deepestExceptionMessage);

            TraceHelper.TraceWithDetails(level, finalMessage, ex.ToString());
        }

        /// <summary>
        /// Gets the inner exception.
        /// </summary>
        /// <param name="ex">The exception.</param>
        /// <returns>Inner exception of the exception. If no inner exception is available, the actual exception is returned.</returns>
        private static Exception GetInnerException(Exception ex)
        {
            return (ex.InnerException != null) ? GetInnerException(ex.InnerException) : ex;
        }
    }
}