declare a method always throws an exception?

c# .net exception exception-handling checked-exceptions
noctonura picture noctonura · Oct 8, 2010 · Viewed 10.7k times · Source

I have a method like...

int f() {
  try {
    int i = process();
    return i;
  } catch(Exception ex) {
    ThrowSpecificFault(ex);
  }
}

This produces a compiler error, "not all code paths return a value". But in my case ThrowSpecificFault() will always throw (the appropriate) exception. So I am forced to a put a return value at the end but this is ugly.

The purpose of this pattern in the first place is because "process()" is a call to an external web service but need to translate a variety of different exceptions to match a client's expected interface (~facade pattern I suppose).

Any cleaner way to do this?

Answer

CesarGon picture CesarGon · Oct 8, 2010

I suggest that you convert ThrowSpecificFault(ex) to throw SpecificFault(ex); the SpecificFault method would return the exception object to be thrown rather than throwing it itself. Much cleaner.

This is the pattern recommended by Microsoft's guidelines (find the text "Use exception builder methods").

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