Manual on running test suite
How full is test suite shipped with libcoap to check COAP compliance if I want to implement my own library (for very small devices)?
Is any manual exists how to run this tests?
Maybe OMA published some test suite to do full COAP compliance checking?
The test suite is rather incomplete. There is a small set of unit tests in the tests subdirectory, mostly to check message parsing. There is also some old code from the ETSI CoAP plugtest (this is the organization that has hosted the major interop events during standardization of CoAP). The test specifications can be found here.
Oh, and the unit tests can be run by tests/testdriver (must be configured with --enable-tests, see CI builds).