$ASSERTS

This metacommand enables debug tests with the _ASSERT statement.

Syntax

$ASSERTS[:CONSOLE]

Description

• The metacommand does not require a comment or REM before it. There is no space after the colon.
• 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 is used.

;Note: This metacommand is the main switch to enable debug tests during development. Later just remove this metacommand to compile the program without debugging code, all the _ASSERT statements may remain in the code for later debugging sessions, they are simply ignored without this metacommand.

Example(s)

;Example:Adding test checks for parameter inputs in a function.

'''vb

$ASSERTS:CONSOLE

DO a = INT(RND * 10) b$ = myFunc$(a) PRINT a, , b$ _LIMIT 3 LOOP UNTIL _KEYHIT

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

• _ASSERT
• $CHECKING
• [Relational Operations](Relational Operations)
• [ERROR Codes](ERROR Codes)