Jest to Vitest migration (#230)

* working without clean up

* clean up dependencies

* use test not dev

* add tests for kclErrToDiagnostic

* remove jest config

* remove unneeded @ts-ignore

src/setupTests.ts

@@ -1,17 +1,5 @@
 import '@testing-library/jest-dom'
-import util from 'util'
-import fetch from 'isomorphic-fetch'
-import fs from 'fs'
-
-jest.mock('./env', () => {
-  // and set all the env vars from .env.development
-  const mockVars: { [key: string]: string } = {}
-  fs.readFileSync('.env.development', 'utf8')
-    .split('\n')
-    .map((line) => line.split('='))
-    .forEach(([key, value]) => (mockVars[key] = value))
-  return mockVars
-})
+import { WebSocket } from 'ws'
 
 class MockRTCPeerConnection {
   constructor() {}
@@ -47,8 +35,4 @@ class MockRTCPeerConnection {
 // @ts-ignore
 global.RTCPeerConnection = MockRTCPeerConnection
 // @ts-ignore
-global.fetch = fetch
-
-// @ts-ignore
-global.TextDecoder = util.TextDecoder
-global.TextEncoder = util.TextEncoder
+global.WebSocket = WebSocket