Fix promise type for new TypeScript (#350)

* Update typescript

* Fix promise types

resolve() now expects one input

Author: aminya

package-lock.json

@@ -96,7 +96,7 @@
     "ts-node": "^9.0.0",
     "tslint": "^6.1.3",
     "tslint-config-prettier": "^1.18.0",
-    "typescript": "^4.0.5",
+    "typescript": "^4.2.3",
     "wavy": "^1.0.4",
     "webpack": "^4.44.2",
     "worker-plugin": "^5.0.0"

package.json

@@ -266,7 +266,7 @@ class WorkerPool<ThreadType extends Thread> implements Pool<ThreadType> {
       return taskFailures
     }
 
-    await new Promise((resolve, reject) => {
+    await new Promise<void>((resolve, reject) => {
       const subscription = this.eventObservable.subscribe({
         next(event) {
           if (event.type === PoolEventType.taskQueueDrained) {

src/master/pool.ts

@@ -7,7 +7,7 @@ const doNothing = () => undefined
 export function createPromiseWithResolver<T>(): [Promise<T>, (result: T) => void] {
   let alreadyResolved = false
   let resolvedTo: T
-  let resolver: () => void = doNothing
+  let resolver: (value: T | PromiseLike<T>) => void = doNothing
 
   const promise = new Promise<T>(resolve => {
     if (alreadyResolved) {
@@ -19,7 +19,7 @@ export function createPromiseWithResolver<T>(): [Promise<T>, (result: T) => void
   const exposedResolver = (value: T) => {
     alreadyResolved = true
     resolvedTo = value
-    resolver()
+    resolver(resolvedTo)
   }
   return [promise, exposedResolver]
 }