assert-error (condition form &rest extras)
Return value is unspecified.
This macro tallies a failure if form does not signal an error that is equal to or a subtype of condition-type condition.
Use error to refer to any kind of error. See condition types in the Common Lisp Hyperspec for other possible names.
See assert-eq for a detailed description of assert macros.
This example asserts that foo is supposed to signal an arithmetic error when passed zero.
(assert-error 'arithmetic-error (foo 0))