Cucumber has built in syntax check:
$ cucumber -h
(...)
-d, --dry-run Invokes formatters without executing the steps. This also omits the loading of your support/env.rb file if it exists.
(...)
We should run it for all repositories that contain Cucumber code[1].
1: https://github.com/wikimedia/mediawiki-selenium
Version: wmf-deployment
Severity: normal
Whiteboard: zfilipin