I've written code completely in Hack, and I would like to use Travis CI to test my builds on various HHVM versions with Hack enabled. Does Travis CI support Hack when I select HHVM as the testing platform or is it just PHP?
It provides both hhvm, which can run Hack, and hh_client which checks it.
However, Travis is running Ubuntu 12.04. This means you can only get HHVM 3.6 and will be unable to use any of the more recent features in both HHVM and Hack.