Use EventTarget in worker / browser runtimes

src/Error.ts

@@ -14,7 +14,7 @@ class StripeError extends Error {
   readonly code?: string;
   readonly doc_url?: string;
   readonly param?: string;
-  readonly detail?: string;
+  readonly detail?: string | Error;
   readonly statusCode?: number;
   readonly charge?: string;
   readonly decline_code?: string;

src/StripeEmitter.ts

@@ -0,0 +1,56 @@
+/**
+ * @private
+ * (For internal use in stripe-node.)
+ * Wrapper around the Event Web API.
+ */
+class _StripeEvent extends Event {
+  data?: RequestEvent | ResponseEvent;
+  constructor(eventName: string, data: any) {
+    super(eventName);
+    this.data = data;
+  }
+}
+
+type Listener = (...args: any[]) => any;
+type ListenerWrapper = (event: _StripeEvent) => void;
+
+/** Minimal EventEmitter wrapper around EventTarget. */
+class StripeEmitter {
+  eventTarget: EventTarget;
+  listenerMapping: Map<Listener, ListenerWrapper>;
+
+  constructor() {
+    this.eventTarget = new EventTarget();
+    this.listenerMapping = new Map();
+  }
+
+  on(eventName: string, listener: Listener): void {
+    const listenerWrapper: ListenerWrapper = (event: _StripeEvent): void => {
+      listener(event.data);
+    };
+    this.listenerMapping.set(listener, listenerWrapper);
+    return this.eventTarget.addEventListener(eventName, listenerWrapper);
+  }
+
+  removeListener(eventName: string, listener: Listener): void {
+    const listenerWrapper = this.listenerMapping.get(listener);
+    this.listenerMapping.delete(listener);
+    return this.eventTarget.removeEventListener(eventName, listenerWrapper!);
+  }
+
+  once(eventName: string, listener: Listener): void {
+    const listenerWrapper: ListenerWrapper = (event: _StripeEvent): void => {
+      listener(event.data);
+    };
+    this.listenerMapping.set(listener, listenerWrapper);
+    return this.eventTarget.addEventListener(eventName, listenerWrapper, {
+      once: true,
+    });
+  }
+
+  emit(eventName: string, data: RequestEvent | ResponseEvent): boolean {
+    return this.eventTarget.dispatchEvent(new _StripeEvent(eventName, data));
+  }
+}
+
+export = StripeEmitter;

src/StripeResource.ts

@@ -222,7 +222,7 @@ StripeResource.prototype = {
         opts.auth,
         {headers, settings, streaming: opts.streaming},
         requestCallback,
-        this.requestDataProcessor
+        this.requestDataProcessor?.bind(this)
       );
     });
   },