A Catch clause that only rethrows the caught exception has the same effect as omitting the Catch altogether and letting it bubble up automatically, but with more code and the additional detriment of leaving maintainers scratching their heads.

Such clauses should either be eliminated or populated with the appropriate logic.

Noncompliant Code Example

Dim s As String = ""
Try
    s = File.ReadAllText(fileName)
Catch e As Exception
    Throw
End Try

Compliant Solution

Dim s As String = ""
Try
    s = File.ReadAllText(fileName)
Catch e As Exception
    logger.LogError(e)
    Throw
End Try

or

Dim s As String = File.ReadAllText(fileName)

Exceptions

This rule will not generate issues for Catch blocks with just Throw inside if they are followed by a Catch block for a more general exception type that does more than just rethrowing the exception.

Dim s As String = ""
Try
    s = File.ReadAllText(fileName)
Catch e As IOException 'Compliant, if removed will change the logic
    Throw
Catch e As Exception 'Compliant, does more than just rethrow
    logger.LogError(e)
    Throw
End Try