A couple of my coworkers stumbled on an interesting issue. Here are simple tests.
Thanks Jamie for additional tests and findings.
Results in this output...
It seems that type="numeric" argument in the testFUnction should fail but it doesn't.
Also isNumeric(testVal ) doesn't agree with isValid('numeric', testval) though ColdFusion documentation says it should:
"float or numeric: a numeric value; equivalent to the IsNumeric function."
Also we confirmed (thanks Brian) that this exists in ColdFusion 9 beta.