This vocabulary provides support for testing code in a clean, predicatable manner.
Assertion predicates first check the stack for underflow; if the stack is deep enough, their embedded predicates are applied; if not, the assertion fails.
The result of each assertion - including the underflow check - is ANDed with the assertionFlag which can then be tested after the containing thread has finished executing; this is handled by the .assertion word class.
For custom behaviour, revector preCond and/or postCond; by default the pre-condition is an effective nop while the post- condition simply prints 'Success' or 'Failure'.
Given that each assertion predicate mutates assertionFlag, use of the word class .assertion is encouraged; this resets the assertionFlag before execution and push its final value to the stack before calling postCond when the thread exits.
NOTE: For simplicity of implementation, failure within a word of class .assertion will not result in immediate termination; instead, the false value of assertionFlag is left to propagate.
( Our assertions ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ) ( n.b, underflow is dealt with sanely ) : a1 ( xyz- ) 30 assert= 20 assert= 10 assert= ; assertion : a2 ( xy- ) assertTrue assertFalse ; assertion : a3 ( x- ) 5 assert< ; assertion ( Simple demo ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ) : go "\n----------" puts 10 20 30 a1 30 20 10 a1 "\n----------" puts 10 a1 "\n----------" puts a1 "\n----------" puts -1 0 a2 0 -1 a2 -1 -1 a2 -1 a2 "\n----------" puts 3 a3 4 a3 5 a3 a3 "\n----------" puts ; clear go ( Adjusting pre- and post- conditions ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ) : myPreCond .s ; : myPostCond [ "Fatal error: assertion failure." puts bye ] ifFalse ; &myPostCond is postCond &myPreCond is preCond ( 'go' will now exit on first failure ) go
| Name | Stack | Usage |
|---|---|---|
| assertionFlag | -a | Variable. This holds a true (-1) or false (0) value indicating whether the current set of assertions have passed or failed. The .assertion class will set this to true automatically. |
| assert | f- | Updates the assertionFlag using bitwise AND |
| available | n-f | Checks to see if there are at least n items on the stack. Returns true if there are, or false otherwise |
| assert= | nn- | Check to see if two values are equal |
| assertFalse | f- | Check to see if flag is false (0) |
| assertTrue | f- | Check to see if flag is true (non-zero) |
| assert> | nn- | Check to see if n1 is greather than n2 |
| assert>= | nn- | Check to see if n1 is greater than or equal to n2 |
| assert< | nn- | Check to see if n1 is less than n2 |
| assert<= | nn- | Check to see if n1 is less than or equal to n2 |
| putAssertion | f- | Display 'Success' or 'Failure' based on flag |
| preCond | - | Hook, does nothing bu default |
| postCond | f- | Hook, displays 'Success' or 'Failure' by default |
| .assertion | a- | Class handler for assertions |
| assertion | - | Change the class of a function to .asssertion |