fix(abort-controller): make AbortSignal WHATWG Spec compliant (#1699)

Author: trivikr

packages/abort-controller/src/AbortSignal.ts

@@ -1,8 +1,8 @@
 import { AbortHandler, AbortSignal as IAbortSignal } from "@aws-sdk/types";
 
 export class AbortSignal implements IAbortSignal {
-  public onabort?: AbortHandler;
-  private _aborted!: boolean;
+  public onabort: AbortHandler | null = null;
+  private _aborted = false;
 
   constructor() {
     Object.defineProperty(this, "_aborted", {
@@ -24,8 +24,8 @@ export class AbortSignal implements IAbortSignal {
   abort(): void {
     this._aborted = true;
     if (this.onabort) {
-      this.onabort();
-      this.onabort = undefined;
+      this.onabort(this);
+      this.onabort = null;
     }
   }
 }

packages/fetch-http-handler/src/fetch-http-handler.spec.ts

@@ -105,6 +105,7 @@ describe.skip(FetchHttpHandler.name, () => {
       fetchHttpHandler.handle({} as any, {
         abortSignal: {
           aborted: true,
+          onabort: null,
         },
       })
     ).rejects.toHaveProperty("name", "AbortError");
@@ -130,6 +131,7 @@ describe.skip(FetchHttpHandler.name, () => {
     await fetchHttpHandler.handle({} as any, {
       abortSignal: {
         aborted: false,
+        onabort: null,
       },
     });
 

packages/node-http-handler/src/node-http-handler.spec.ts

@@ -450,6 +450,7 @@ describe("NodeHttpHandler", () => {
           {
             abortSignal: {
               aborted: true,
+              onabort: null,
             },
           }
         )

packages/node-http-handler/src/node-http2-handler.spec.ts

@@ -143,6 +143,7 @@ describe("NodeHttp2Handler", () => {
         nodeH2Handler.handle(new HttpRequest(getMockReqOptions()), {
           abortSignal: {
             aborted: true,
+            onabort: null,
           },
         })
       ).rejects.toHaveProperty("name", "AbortError");
@@ -161,6 +162,7 @@ describe("NodeHttp2Handler", () => {
         nodeH2Handler.handle(new HttpRequest(getMockReqOptions()), {
           abortSignal: {
             aborted: true,
+            onabort: null,
           },
         })
       ).rejects.toHaveProperty("name", "AbortError");

packages/types/src/abort.ts

@@ -1,5 +1,5 @@
 export interface AbortHandler {
-  (): void;
+  (this: AbortSignal, ev: any): any;
 }
 
 /**
@@ -18,7 +18,7 @@ export interface AbortSignal {
    * A function to be invoked when the action represented by this signal has
    * been cancelled.
    */
-  onabort?: AbortHandler;
+  onabort: AbortHandler | null;
 }
 
 /**