There are some negative admin CLI tests (SE) that attempt to pass invalid types
to the list-components command using the --type parameter. The docs (man page
and online doc) state that valid types are: application, appclient, connector,
ejb, jruby, web and webservice, or no type in which case all types are returned.
In 3.1 if you pass an invalid type, the command still succeeds and exits with a
value of 0. In 2.1, I assume based on the tests, the command fails and exits
with an exit status of 1.
As an example in 3.1:
% ./asadmin list-components --type foo
Nothing to list.
Command list-components executed successfully.
To be fair the doc does not state that an error should be propagated to the user
if the type is not valid. I can certainly see both views as valid. Left as a
decision to the dev/QA team.