adds +expect-fail to test library
(~(dunk ut p.expected) %expected)
== ==
result
+:: +expect-fail: kicks a trap, expecting crash. pretty-prints if succeeds
+::
+++ expect-fail
+ |= a=(trap)
+ ^- tang
+ =/ b (mule a)
+ ?- -.b
+ %| ~
+ %& [leaf+"expected failure - succeeded" ~]
+ ==
:: +category: prepends a name to an error result; passes successes unchanged
::
++ category
