$ASSERTS

The $ASSERTS metacommand enables debug tests with the _ASSERT macro.

Syntax

$ASSERTS

$ASSERTS:CONSOLE

Description

• This metacommand does not require a comment ' or REM before it. There is no space between the metacommand name, the colon and the CONSOLE parameter.
• If this metacommand is used in a program and any of the set _ASSERT checkpoints will fail, then the program will stop with an _ASSERT failed error.
• Detailed error messages passed to the _ASSERT statement will be displayed in the console window, but only if $ASSERTS:CONSOLE is used.
• The $ASSERTS metacommand serves as main switch to enable debug tests during development. Later you just need to remove the metacommand while leaving all the _ASSERT statements in place for later debugging sessions, they are simply ignored without the metacommand.
• In newer versions a precompiler flag named _ASSERTS_ is available (see Availability):
  • The flag is one(1) if the program is compiled with $ASSERTS enabled and zero(0) if compiled without it.
  • You may use it to include/exclude debugging related code using precompiler $IF..$ELSE...$END IF blocks.

Availability

• 

  v1.4

• 

  all

• 
• 

  yes

• 

  yes

• 

  yes

• Since QB64-PE v4.0.0 the precompiler flag _ASSERTS_ indicates the state of $ASSERTS at compile time.

Examples

Example

Adding test checks for parameter inputs in a function.

$ASSERTS:CONSOLE DO a = INT(RND * 10) b$ = myFunc$(a) PRINT a, , b$ _LIMIT 3 LOOP UNTIL _KEYHIT END FUNCTION myFunc$ (value AS SINGLE) _ASSERT value > 0, "Value cannot be zero" _ASSERT value <= 10, "Value cannot exceed 10" IF value > 1 THEN plural$ = "s" myFunc$ = STRING$(value, "*") + STR$(value) + " star" + plural$ + " :-)" END FUNCTION

See also

• Metacommand
• _ASSERT
• $CHECKING
• Relational Operations
• ERROR Codes

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