Add ISourceBufferList. Remove unused activeSourceBuffers

.eslintrc.js

@@ -67,6 +67,10 @@ module.exports = {
             message:
               "Avoid relying on `SourceBuffer` directly unless it is API-facing. Prefer our more restricted `ISourceBuffer` type",
           },
+          SourceBufferList: {
+            message:
+              "Avoid relying on `SourceBufferList` directly unless it is API-facing. Prefer our more restricted `ISourceBufferList` type",
+          },
         },
       },
     ],

src/compat/browser_compatibility_types.ts

@@ -85,6 +85,33 @@ export interface IEventTarget<TEventMap> {
   ): void;
 }
 
+/** Events potentially dispatched by an `ISourceBufferList` */
+export interface ISourceBufferListEventMap {
+  addsourcebuffer: Event;
+  removesourcebuffer: Event;
+}
+
+/**
+ * More restrictive and type-compatible with the `SourceBufferList` type (i.e. a
+ * `SourceBufferList` is a valid `ISourceBufferList`), the `ISourceBufferList`
+ * type allows to:
+ *
+ *   - re-define some attributes or methods in cases where we detected that some
+ *     platforms have a different implementation.
+ *
+ *   - list all `SourceBufferList` attributes, methods and events that are
+ *     relied on by the RxPlayer.
+ *
+ *   - Allow an easier re-definition of that API for tests or for platforms
+ *     which do not implement it.
+ */
+export interface ISourceBufferList extends IEventTarget<ISourceBufferListEventMap> {
+  readonly length: number;
+  onaddsourcebuffer: ((evt: Event) => void) | null;
+  onremovesourcebuffer: ((evt: Event) => void) | null;
+  [index: number]: ISourceBuffer;
+}
+
 /** Events potentially dispatched by an `IMediaSource` */
 export interface IMediaSourceEventMap {
   sourceopen: Event;
@@ -106,11 +133,10 @@ export interface IMediaSourceEventMap {
  *     which do not implement it.
  */
 export interface IMediaSource extends IEventTarget<IMediaSourceEventMap> {
-  activeSourceBuffers: SourceBufferList;
   duration: number;
   handle?: MediaProvider | IMediaSource | undefined;
   readyState: "closed" | "open" | "ended";
-  sourceBuffers: SourceBufferList;
+  sourceBuffers: ISourceBufferList;
 
   addSourceBuffer(type: string): ISourceBuffer;
   clearLiveSeekableRange(): void;
@@ -302,6 +328,13 @@ function testSourceBuffer(x: SourceBuffer) {
 function assetCompatibleISourceBuffer(_x: ISourceBuffer) {
   // Noop
 }
+// @ts-expect-error unused function, just used for compile-time typechecking
+function testSourceBufferList(x: SourceBufferList) {
+  assetCompatibleISourceBufferList(x);
+}
+function assetCompatibleISourceBufferList(_x: ISourceBufferList) {
+  // Noop
+}
 /* eslint-enable @typescript-eslint/no-unused-vars, @typescript-eslint/ban-types */
 
 /**

src/mse/utils/end_of_stream.ts

@@ -17,6 +17,7 @@
 import type {
   IMediaSource,
   ISourceBuffer,
+  ISourceBufferList,
 } from "../../compat/browser_compatibility_types";
 import {
   onRemoveSourceBuffers,
@@ -32,9 +33,7 @@ import TaskCanceller from "../../utils/task_canceller";
  * @param {SourceBufferList} sourceBuffers
  * @returns {Array.<SourceBuffer>}
  */
-function getUpdatingSourceBuffers(
-  sourceBuffers: SourceBufferList | ISourceBuffer[],
-): ISourceBuffer[] {
+function getUpdatingSourceBuffers(sourceBuffers: ISourceBufferList): ISourceBuffer[] {
   const updatingSourceBuffers: ISourceBuffer[] = [];
   for (let i = 0; i < sourceBuffers.length; i++) {
     const SourceBuffer = sourceBuffers[i];

src/mse/utils/media_source_duration_updater.ts

@@ -16,7 +16,7 @@
 
 import type {
   IMediaSource,
-  ISourceBuffer,
+  ISourceBufferList,
 } from "../../compat/browser_compatibility_types";
 import { onSourceOpen, onSourceEnded, onSourceClose } from "../../compat/event_listeners";
 import hasIssuesWithHighMediaSourceDuration from "../../compat/has_issues_with_high_media_source_duration";
@@ -249,7 +249,7 @@ const enum MediaSourceDurationUpdateStatus {
  * @returns {Object}
  */
 function createSourceBuffersUpdatingReference(
-  sourceBuffers: SourceBufferList | ISourceBuffer[],
+  sourceBuffers: ISourceBufferList,
   cancelSignal: CancellationSignal,
 ): IReadOnlySharedReference<boolean> {
   if (sourceBuffers.length === 0) {