test: add and assert readable/writable arguments
Checklist
-
make -j8 test
(UNIX), orvcbuild test nosign
(Windows) passes -
commit message follows commit guidelines
Affected core subsystem(s)
test
Description of change
Currently the readable and writable arguments are not specified in the req.oncomplete method. Adding and asserting that they are always true (which is always the case for TCP). This might seem unnecessary but it can't hurt to have them to pickup any breaking modifications made to ConnectionWrap::AfterConnect in the future.