In resteasy-jaxrs the test org.jboss.resteasy.plugins.server.tjws.TJWSServletServerTest.testFile() might fail. The problem is root.getFile() method that returns full path to resources that are tested. However if path contains invalid characters, spaces for instance, these are url encoded (space = %20) which later in asserts results in file-not-found response.

RESOLVED IN UPLOADED PATCH
Solution is to use java.net.URI class to wrap root.getFile() method result.