Prevent compilation

Why would you want to do this?

I had to write and test some code to hook up to a piece of external equipment.

To test the code when the equipment was not there, I set a variable TESTING which generated fake replies from the equipment so that the rest of the program could be tested.

The problem? What if some idiot (i.e. me) forgot to reset the TESTING variable, compiled the program and sent it to the customer. Disaster!

This code prevents compilation when TESTING is true.

Another approach would have been to see if we were in the IDE and generate fake data when we were, but that would not have worked here as we sometimes needed to debug in the IDE with the equipment present.

VB Code:

Option Explicit
Public TESTING As Boolean
#Const TESTING = True 'Set true or false as required
 
Sub TestingCheck()
  
  'Dummy procedure which is never called.
  
  #If TESTING Then
    Will not compile if TESTING is true
    'The above line appears red in the VB6 code editor.
    'That's expected because we are forcing a compile error. Don't edit it! 
  #End If
End Sub
 
Public Sub Main()
  
  'Set a public variable so we can check it from
  'anywhere in the program. (The compiler constant
  'with the same name applies ONLY in the module
  'in which it is declared.
  #If TESTING Then
    TESTING = True
  #End If
 
  'Example of use >>>>>>>>>>>>>>>>>>>
  'Dim DataFromSpacecraft As String
  'If TESTING Then
  '
  '  'Supply dummy data for testing the application
  '  DataFromSpacecraft = "Hello earth!"
  '  
  'Else
  '
  '  'Get real data
  '  DataFromSpacecraft = GetDataFromSpacecraft()
  '  
  'End If
  'Example of use >>>>>>>>>>>>>>>>>>>
 
  
End Sub

Why would it not compile if TESTING is true? :confused:

The code...

VB Code:

#If TESTING Then
    Will not compile if TESTING is true
  #End If

...does the work.

If TESTING is true the compiler tries to compile "Will not compile if TESTING is true" and falls over because it is an illegal line. If TESTING is false, the complier just misses it out and does not try to compile it.

Sorry, didn't try it before I asked.