Getting all messages from InnerException(s)?

Question

Is there any way to write a LINQ style \"short hand\" code for walking to all levels of InnerException(s) of Exception thrown? I would prefer to write it in place instead of

Answer 1

I'm just going to leave the most concise version here:

public static class ExceptionExtensions
{
    public static string GetMessageWithInner(this Exception ex) =>
        string.Join($";{ Environment.NewLine }caused by: ",
            GetInnerExceptions(ex).Select(e => $"'{ e.Message }'"));

    public static IEnumerable<Exception> GetInnerExceptions(this Exception ex)
    {
        while (ex != null)
        {
            yield return ex;
            ex = ex.InnerException;
        }
    }
}

Answer 2

How about this code:

private static string GetExceptionMessages(this Exception e, string msgs = "")
{
  if (e == null) return string.Empty;
  if (msgs == "") msgs = e.Message;
  if (e.InnerException != null)
    msgs += "\r\nInnerException: " + GetExceptionMessages(e.InnerException);
  return msgs;
}

Usage:

Console.WriteLine(e.GetExceptionMessages())

Example of output:

There was no endpoint listening at http://nnn.mmm.kkk.ppp:8000/routingservice/router that could accept the message. This is often caused by an incorrect address or SOAP action. See InnerException, if present, for more details.

InnerException: Unable to connect to the remote server

InnerException: No connection could be made because the target machine actively refused it 127.0.0.1:8000

Answer 3

    public static string GetExceptionMessage(Exception ex)
    {
        if (ex.InnerException == null)
        {
            return string.Concat(ex.Message, System.Environment.NewLine, ex.StackTrace);
        }
        else
        {
            // Retira a última mensagem da pilha que já foi retornada na recursividade anterior
            // (senão a última exceção - que não tem InnerException - vai cair no último else, retornando a mesma mensagem já retornada na passagem anterior)
            if (ex.InnerException.InnerException == null)
                return ex.InnerException.Message;
            else
                return string.Concat(string.Concat(ex.InnerException.Message, System.Environment.NewLine, ex.StackTrace), System.Environment.NewLine, GetExceptionMessage(ex.InnerException));
        }
    }

Answer 4

You mean something like this?

public static class Extensions
{
    public static IEnumerable<Exception> GetInnerExceptions(this Exception ex)
    {
        if (ex == null)
        {
            throw new ArgumentNullException("ex");
        }

        var innerException = ex;
        do
        {
            yield return innerException;
            innerException = innerException.InnerException;
        }
        while (innerException != null);
    }
}

This way you could LINQ over your entire exceptions hierarchy, like this:

exception.GetInnerExceptions().Where(e => e.Message == "Oops!");

Answer 5

LINQ is generally used to work with collections of objects. However, arguably, in your case there is no collection of objects (but a graph). So even though some LINQ code might be possible, IMHO it would be rather convoluted or artificial.

On the other hand, your example looks like a prime example where extension methods are actually reasonable. Not to speak of issues like reuse, encapsulation, etc.

I would stay with an extension method, although I might have implemented it that way:

public static string GetAllMessages(this Exception ex)
{
   if (ex == null)
     throw new ArgumentNullException("ex");

   StringBuilder sb = new StringBuilder();

   while (ex != null)
   {
      if (!string.IsNullOrEmpty(ex.Message))
      {
         if (sb.Length > 0)
           sb.Append(" ");

         sb.Append(ex.Message);
      }

      ex = ex.InnerException;
   }

   return sb.ToString();
}

But that is largely an issue of taste.

Answer 6

To add to others, you may want to let the user decide on how to separate the messages:

    public static string GetAllMessages(this Exception ex, string separator = "\r\nInnerException: ")
    {
        if (ex.InnerException == null)
            return ex.Message;

        return ex.Message + separator + GetAllMessages(ex.InnerException, separator);
    }