test completion snippets
Summary:
clientLsp will send snippets to clients that support them, or plain text to other clients.
Our integration tests (prior to this diff) only tested the "plain text" path.
But our major clients (VSCode, Atom) support snippets.
This diff changes our integration tests to exercise the snippet path.
(I could have made two separate integration test paths, one of which tested snippets and one which didn't. But that seemed like too much work).
Ultimate goal: a user reported that we're sending the wrong snippets, because we haven't escaped $ in them, and VSCode rightly declines to show our snippets.
Reviewed By: arxanas
Differential Revision:
D19509477
fbshipit-source-id:
4a1e8a99c0c27a8fd04761579f33736abc27662f