Steps

1. yarn
2. Switch TS to 3.1.1 version
3. Open src/test.ts
4. Press fast . (dot) for i and delete dot. Fast repeat few times
5. See global completions

Additional notes

1. This bug doesn't happen if delete 4 vscode-* modules from node_modules folder
2. This bug isn't reproducible with only these modules (4 vscode-*) alone in node_modules