Use MessageEvent in EventSource#addEventListener (#1182)

* Use MessageEvent in EventSource#addEventListener

Fixes #736

* Retain EventSource's original listener

* Add test for MessageEvent being the default overload

Author: Alexendoo

baselines/dom.generated.d.ts

@@ -4928,8 +4928,10 @@ interface EventSource extends EventTarget {
     readonly CONNECTING: number;
     readonly OPEN: number;
     addEventListener<K extends keyof EventSourceEventMap>(type: K, listener: (this: EventSource, ev: EventSourceEventMap[K]) => any, options?: boolean | AddEventListenerOptions): void;
+    addEventListener(type: string, listener: (this: EventSource, event: MessageEvent) => any, options?: boolean | AddEventListenerOptions): void;
     addEventListener(type: string, listener: EventListenerOrEventListenerObject, options?: boolean | AddEventListenerOptions): void;
     removeEventListener<K extends keyof EventSourceEventMap>(type: K, listener: (this: EventSource, ev: EventSourceEventMap[K]) => any, options?: boolean | EventListenerOptions): void;
+    removeEventListener(type: string, listener: (this: EventSource, event: MessageEvent) => any, options?: boolean | EventListenerOptions): void;
     removeEventListener(type: string, listener: EventListenerOrEventListenerObject, options?: boolean | EventListenerOptions): void;
 }
 

baselines/serviceworker.generated.d.ts

@@ -1300,8 +1300,10 @@ interface EventSource extends EventTarget {
     readonly CONNECTING: number;
     readonly OPEN: number;
     addEventListener<K extends keyof EventSourceEventMap>(type: K, listener: (this: EventSource, ev: EventSourceEventMap[K]) => any, options?: boolean | AddEventListenerOptions): void;
+    addEventListener(type: string, listener: (this: EventSource, event: MessageEvent) => any, options?: boolean | AddEventListenerOptions): void;
     addEventListener(type: string, listener: EventListenerOrEventListenerObject, options?: boolean | AddEventListenerOptions): void;
     removeEventListener<K extends keyof EventSourceEventMap>(type: K, listener: (this: EventSource, ev: EventSourceEventMap[K]) => any, options?: boolean | EventListenerOptions): void;
+    removeEventListener(type: string, listener: (this: EventSource, event: MessageEvent) => any, options?: boolean | EventListenerOptions): void;
     removeEventListener(type: string, listener: EventListenerOrEventListenerObject, options?: boolean | EventListenerOptions): void;
 }
 

baselines/sharedworker.generated.d.ts

@@ -1244,8 +1244,10 @@ interface EventSource extends EventTarget {
     readonly CONNECTING: number;
     readonly OPEN: number;
     addEventListener<K extends keyof EventSourceEventMap>(type: K, listener: (this: EventSource, ev: EventSourceEventMap[K]) => any, options?: boolean | AddEventListenerOptions): void;
+    addEventListener(type: string, listener: (this: EventSource, event: MessageEvent) => any, options?: boolean | AddEventListenerOptions): void;
     addEventListener(type: string, listener: EventListenerOrEventListenerObject, options?: boolean | AddEventListenerOptions): void;
     removeEventListener<K extends keyof EventSourceEventMap>(type: K, listener: (this: EventSource, ev: EventSourceEventMap[K]) => any, options?: boolean | EventListenerOptions): void;
+    removeEventListener(type: string, listener: (this: EventSource, event: MessageEvent) => any, options?: boolean | EventListenerOptions): void;
     removeEventListener(type: string, listener: EventListenerOrEventListenerObject, options?: boolean | EventListenerOptions): void;
 }
 

baselines/webworker.generated.d.ts

@@ -1338,8 +1338,10 @@ interface EventSource extends EventTarget {
     readonly CONNECTING: number;
     readonly OPEN: number;
     addEventListener<K extends keyof EventSourceEventMap>(type: K, listener: (this: EventSource, ev: EventSourceEventMap[K]) => any, options?: boolean | AddEventListenerOptions): void;
+    addEventListener(type: string, listener: (this: EventSource, event: MessageEvent) => any, options?: boolean | AddEventListenerOptions): void;
     addEventListener(type: string, listener: EventListenerOrEventListenerObject, options?: boolean | AddEventListenerOptions): void;
     removeEventListener<K extends keyof EventSourceEventMap>(type: K, listener: (this: EventSource, ev: EventSourceEventMap[K]) => any, options?: boolean | EventListenerOptions): void;
+    removeEventListener(type: string, listener: (this: EventSource, event: MessageEvent) => any, options?: boolean | EventListenerOptions): void;
     removeEventListener(type: string, listener: EventListenerOrEventListenerObject, options?: boolean | EventListenerOptions): void;
 }
 

src/build/emitter.ts

@@ -1064,6 +1064,13 @@ export function emitWebIdl(
           : "EventListenerOptions";
       if (tryEmitTypedEventHandlerForInterface(addOrRemove, optionsType)) {
         // only emit the string event handler if we just emitted a typed handler
+
+        if (i.name === "EventSource") {
+          printer.printLine(
+            `${fPrefix}${addOrRemove}EventListener(type: string, listener: (this: EventSource, event: MessageEvent) => any, options?: boolean | ${optionsType}): void;`
+          );
+        }
+
         printer.printLine(
           `${fPrefix}${addOrRemove}EventListener(type: string, listener: EventListenerOrEventListenerObject, options?: boolean | ${optionsType}): void;`
         );

unittests/files/eventsource.ts

@@ -0,0 +1,7 @@
+const source = new EventSource("/");
+
+source.addEventListener("custom", (event) => {
+  event.data; // MessageEvent specific
+});
+source.addEventListener("custom", (event: MessageEvent) => {});
+source.addEventListener("with-handle-event", { handleEvent(event: Event) {} });