[TS migration] Migrate 'Pusher' lib to TypeScript

[melvin-bot]

TypeScript migration

Make sure you read through our TypeScript's style guide, cheatsheet and PropTypes conversion table before you start working on this migration issue.

Files

Path	Dependencies
src/libs/Pusher/pusher.js	6
src/libs/Pusher/EventType.js	0
src/libs/Pusher/library/index.native.js	1
src/libs/Pusher/library/index.js	1

[melvin-bot]

This issue has not been updated in over 15 days. eroding to Monthly issue.

P.S. Is everyone reading this sure this is really a near-term priority? Be brave: if you disagree, go ahead and close it out. If someone disagrees, they'll reopen it, and if they don't: one less thing to do!

[kubabutkiewicz]

Hi, I'm Jakub from Callstack - expert contributor group - and I would like to take a look at this issue.