fix(typescript): tighten TypeScript typings and modernize project tooling configuration

ts/smartpromise.classes.deferred.ts

@@ -3,16 +3,16 @@ export interface IResolve<T> {
 }
 
 export interface IReject {
-  (reason?: any): void;
+  (reason?: unknown): void;
 }
 
 export type TDeferredStatus = 'pending' | 'fulfilled' | 'rejected';
 
 export class Deferred<T> {
   public promise: Promise<T>;
-  public resolve: IResolve<T>;
-  public reject: IReject;
-  public status: TDeferredStatus;
+  public resolve!: IResolve<T>;
+  public reject!: IReject;
+  public status!: TDeferredStatus;
   public claimed = false;
   public claim() {
     if (this.claimed) {
@@ -21,8 +21,8 @@ export class Deferred<T> {
     this.claimed = true;
   }
 
-  public startedAt: number;
-  public stoppedAt: number;
+  public startedAt!: number;
+  public stoppedAt!: number;
   public get duration(): number {
     if (this.stoppedAt) {
       return this.stoppedAt - this.startedAt;
@@ -33,12 +33,12 @@ export class Deferred<T> {
 
   constructor() {
     this.promise = new Promise<T>((resolve, reject) => {
-      this.resolve = (valueArg: T | PromiseLike<T>) => {
+      this.resolve = (valueArg?: T | PromiseLike<T>) => {
         this.status = 'fulfilled';
         this.stoppedAt = Date.now();
-        resolve(valueArg);
+        resolve(valueArg as T | PromiseLike<T>);
       };
-      this.reject = (reason: any) => {
+      this.reject = (reason?: unknown) => {
         this.status = 'rejected';
         this.stoppedAt = Date.now();
         reject(reason);
@@ -49,6 +49,6 @@ export class Deferred<T> {
   }
 }
 
-export const defer = <T>() => {
+export const defer = <T = void>() => {
   return new Deferred<T>();
-};
+};