From 20d60cf318f08ab7018ce9ec4c9aaf51e3346358 Mon Sep 17 00:00:00 2001
From: Florent <florent.bouisset@gmail.com>
Date: Wed, 31 Jul 2024 15:33:09 +0200
Subject: [PATCH] use function overloading for better types

---
 src/compat/eme/eme-api-implementation.ts     |  9 ++++++---
 src/compat/event_listeners.ts                | 20 ++++++++++++++++++++
 src/main_thread/decrypt/content_decryptor.ts |  3 +--
 3 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/src/compat/eme/eme-api-implementation.ts b/src/compat/eme/eme-api-implementation.ts
index 0fc9e924f1..5a8c2833d4 100644
--- a/src/compat/eme/eme-api-implementation.ts
+++ b/src/compat/eme/eme-api-implementation.ts
@@ -20,7 +20,10 @@ import getMozMediaKeysCallbacks, {
 import getOldKitWebKitMediaKeyCallbacks, {
   isOldWebkitMediaElement,
 } from "./custom_media_keys/old_webkit_media_keys";
-import type { ICustomMediaKeys } from "./custom_media_keys/types";
+import type {
+  ICustomMediaEncryptedEvent,
+  ICustomMediaKeys,
+} from "./custom_media_keys/types";
 import getWebKitMediaKeysCallbacks from "./custom_media_keys/webkit_media_keys";
 import { WebKitMediaKeysConstructor } from "./custom_media_keys/webkit_media_keys_constructor";
 
@@ -64,7 +67,7 @@ export interface IEmeApiImplementation {
    */
   onEncrypted: (
     target: IEventTargetLike,
-    listener: (evt: unknown) => void,
+    listener: (evt: ICustomMediaEncryptedEvent) => void,
     cancelSignal: CancellationSignal,
   ) => void;
 
@@ -286,7 +289,7 @@ function createOnEncryptedForWebkit(): IEmeApiImplementation["onEncrypted"] {
   );
   const onEncrypted = (
     target: IEventTargetLike,
-    listener: (event?: Event) => void,
+    listener: (event: ICustomMediaEncryptedEvent) => void,
     cancelSignal: CancellationSignal,
   ) => {
     compatibleEventListener(
diff --git a/src/compat/event_listeners.ts b/src/compat/event_listeners.ts
index 073bd8545d..9500fb9a3c 100644
--- a/src/compat/event_listeners.ts
+++ b/src/compat/event_listeners.ts
@@ -30,6 +30,7 @@ import type {
   IEventTarget,
   IMediaElement,
 } from "./browser_compatibility_types";
+import type { ICustomMediaEncryptedEvent } from "./eme/custom_media_keys/types";
 
 const BROWSER_PREFIXES = ["", "webkit", "moz", "ms"];
 
@@ -105,6 +106,16 @@ export type IEventTargetLike = HTMLElement | IEventEmitterLike | IEventEmitter<u
  * @returns {Function} - Returns function allowing to easily add a callback to
  * be triggered when that event is emitted on a given event target.
  */
+
+function createCompatibleEventListener(
+  eventNames: Array<"needkey" | "encrypted">,
+  prefixes?: string[],
+): (
+  element: IEventTargetLike,
+  listener: (event: ICustomMediaEncryptedEvent) => void,
+  cancelSignal: CancellationSignal,
+) => void;
+
 function createCompatibleEventListener(
   eventNames: string[],
   prefixes?: string[],
@@ -112,6 +123,15 @@ function createCompatibleEventListener(
   element: IEventTargetLike,
   listener: (event?: Event) => void,
   cancelSignal: CancellationSignal,
+) => void;
+
+function createCompatibleEventListener(
+  eventNames: string[] | Array<"needkey" | "encrypted">,
+  prefixes?: string[],
+): (
+  element: IEventTargetLike,
+  listener: (event?: Event | MediaEncryptedEvent) => void,
+  cancelSignal: CancellationSignal,
 ) => void {
   let mem: string | undefined;
   const prefixedEvents = eventPrefixed(eventNames, prefixes);
diff --git a/src/main_thread/decrypt/content_decryptor.ts b/src/main_thread/decrypt/content_decryptor.ts
index 53c034da06..07726b706a 100644
--- a/src/main_thread/decrypt/content_decryptor.ts
+++ b/src/main_thread/decrypt/content_decryptor.ts
@@ -17,7 +17,6 @@
 import type { IMediaElement } from "../../compat/browser_compatibility_types";
 import type { ICustomMediaKeys, ICustomMediaKeySystemAccess } from "../../compat/eme";
 import eme, { getInitData } from "../../compat/eme";
-import type { ICustomMediaEncryptedEvent } from "../../compat/eme/custom_media_keys/types";
 import config from "../../config";
 import { EncryptedMediaError, OtherError } from "../../errors";
 import log from "../../log";
@@ -178,7 +177,7 @@ export default class ContentDecryptor extends EventEmitter<IContentDecryptorEven
       mediaElement,
       (evt) => {
         log.debug("DRM: Encrypted event received from media element.");
-        const initData = getInitData(evt as ICustomMediaEncryptedEvent);
+        const initData = getInitData(evt);
         if (initData !== null) {
           this.onInitializationData(initData);
         }