Fix bug causing completion handlers to sometimes return old results (#1361)

* Fix bug causing completion handlers to sometimes return old results

* Update CHANGELOG.md

Author: Jackson Kearl

CHANGELOG.md

@@ -24,7 +24,7 @@
 - `apollo-tools`
   - <First `apollo-tools` related entry goes here>
 - `vscode-apollo`
-  - <First `vscode-apollo` related entry goes here>
+  - Fix bug causing some editor features to sometimes give stale results [#1361](https://github.com/apollographql/apollo-tooling/pull/1361)
 
 ## `apollo@2.13.1`, `apollo-graphql@0.3.2`
 

packages/apollo-language-server/src/utilities/debouncer.ts

@@ -1,5 +1,5 @@
 import debounce from "lodash.debounce";
 
 export function debounceHandler(handler: (...args: any[]) => any) {
-  return debounce(handler, 400, { trailing: true });
+  return debounce(handler, 400, { leading: true });
 }