update dependencies and code

This is the usual dependency update before a release (scheduled
to be the v3.26.2).

After updating `typescript-eslint`, new linter errors made their
apparitions, for cases where an `any` type is used as a function
argument (the rule in question is
[no-unsafe-argument](https://github.com/typescript-eslint/typescript-eslint/blob/main/packages/eslint-plugin/docs/rules/no-unsafe-argument.md)).

That's a rule we want (`any` is ___bad___ after all!) but RxJS,
our main dependency, does not respect it well.
Especially, some operators which transform an observable into
another without needing to look at the items of the source
Observable (e.g. `mapTo`, `mergeMapTo`, `switchMapTo`,
`ignoreElements`) have an `any` in their type definition for the type
of the source Observable's elements (where an `unknown` would actually
suffice and be type-safe).

Replacing on their side this `any` by `unknown` is planned for their
8.x.x release (which is not yet released). In the meantime, we had to
find a solution.

I chose to do two things:

  1. Replace all the "***To" (`mapTo`, `mergeMapTo` and so on)
     operators by their callback-based equivalent (`map`,
     `mergeMap` and so on).
     I did that mostly because RxJS devs [seems to plan
     deprecating the ***To operators anyway in profit of the
     callback-based ones](ReactiveX/rxjs#6399).

  2. For the last remaining operator, `ignoreElements()`, I just
  disabled the rule with a long comment attached on top of each case.

package.json

@@ -80,63 +80,63 @@
   "dependencies": {
     "next-tick": "1.1.0",
     "pinkie": "2.0.4",
-    "rxjs": "7.3.0"
+    "rxjs": "7.4.0"
   },
   "devDependencies": {
-    "@babel/core": "7.15.5",
-    "@babel/plugin-transform-runtime": "7.15.0",
-    "@babel/preset-env": "7.15.6",
-    "@babel/preset-react": "7.14.5",
-    "@types/chai": "4.2.21",
-    "@types/jest": "27.0.1",
+    "@babel/core": "7.16.5",
+    "@babel/plugin-transform-runtime": "7.16.5",
+    "@babel/preset-env": "7.16.5",
+    "@babel/preset-react": "7.16.5",
+    "@types/chai": "4.3.0",
+    "@types/jest": "27.0.3",
     "@types/mocha": "9.0.0",
-    "@types/node": "16.9.1",
-    "@types/sinon": "10.0.2",
-    "@typescript-eslint/eslint-plugin": "4.31.0",
-    "@typescript-eslint/eslint-plugin-tslint": "4.31.0",
-    "@typescript-eslint/parser": "4.31.0",
+    "@types/node": "16.11.13",
+    "@types/sinon": "10.0.6",
+    "@typescript-eslint/eslint-plugin": "5.7.0",
+    "@typescript-eslint/eslint-plugin-tslint": "5.7.0",
+    "@typescript-eslint/parser": "5.7.0",
     "arraybuffer-loader": "1.0.8",
-    "babel-loader": "8.2.2",
+    "babel-loader": "8.2.3",
     "chai": "4.3.4",
     "cheerio": "1.0.0-rc.10",
-    "core-js": "3.17.3",
-    "esbuild": "0.12.25",
-    "eslint": "7.32.0",
-    "eslint-plugin-import": "2.24.2",
-    "eslint-plugin-jsdoc": "36.1.0",
-    "eslint-plugin-react": "7.25.1",
+    "core-js": "3.19.3",
+    "esbuild": "0.14.5",
+    "eslint": "8.4.1",
+    "eslint-plugin-import": "2.25.3",
+    "eslint-plugin-jsdoc": "37.2.1",
+    "eslint-plugin-react": "7.27.1",
     "esm": "3.2.25",
     "express": "4.17.1",
-    "highlight.js": "11.2.0",
+    "highlight.js": "11.3.1",
     "html-entities": "^2.3.2",
     "istanbul-instrumenter-loader": "3.0.1",
-    "jest": "27.2.0",
-    "karma": "6.3.4",
+    "jest": "27.4.5",
+    "karma": "6.3.9",
     "karma-chrome-launcher": "3.1.0",
     "karma-coverage-istanbul-reporter": "3.0.3",
-    "karma-firefox-launcher": "2.1.1",
+    "karma-firefox-launcher": "2.1.2",
     "karma-mocha": "2.0.1",
-    "karma-mocha-reporter": "2.2.5",
+    "karma-mocha-reporter": "2.2.3",
     "karma-webpack": "5.0.0",
-    "markdown-it": "12.2.0",
-    "mocha": "9.1.1",
+    "markdown-it": "12.3.0",
+    "mocha": "9.1.3",
     "mocha-loader": "5.1.5",
     "raw-loader": "4.0.2",
     "react": "17.0.2",
     "react-dom": "17.0.2",
     "regenerator-runtime": "0.13.9",
     "rimraf": "3.0.2",
-    "sanitize-html": "2.5.0",
+    "sanitize-html": "2.6.1",
     "semver": "7.3.5",
-    "sinon": "11.1.2",
-    "terser-webpack-plugin": "5.2.4",
-    "ts-jest": "27.0.5",
-    "ts-loader": "9.2.5",
+    "sinon": "12.0.1",
+    "terser-webpack-plugin": "5.2.5",
+    "ts-jest": "27.1.1",
+    "ts-loader": "9.2.6",
     "tslint": "6.1.3",
-    "typescript": "4.4.3",
-    "webpack": "5.52.1",
-    "webpack-bundle-analyzer": "4.4.2",
-    "webpack-cli": "4.8.0"
+    "typescript": "4.5.4",
+    "webpack": "5.65.0",
+    "webpack-bundle-analyzer": "4.5.0",
+    "webpack-cli": "4.9.1"
   },
   "scripts-list": {
     "Build a demo page (e.g. to test a code change)": {

src/compat/__tests__/add_text_track.test.ts

@@ -20,6 +20,7 @@
 /* eslint-disable @typescript-eslint/no-var-requires */
 /* eslint-disable @typescript-eslint/no-unsafe-call */
 /* eslint-disable @typescript-eslint/no-unsafe-assignment */
+/* eslint-disable @typescript-eslint/no-unsafe-argument */
 
 describe("compat - addTextTrack", () => {
   beforeEach(() => {

src/compat/__tests__/when_loaded_metadata.test.ts

@@ -20,6 +20,7 @@
 /* eslint-disable @typescript-eslint/no-unsafe-call */
 /* eslint-disable @typescript-eslint/no-unsafe-assignment */
 /* eslint-disable @typescript-eslint/no-unsafe-return */
+/* eslint-disable @typescript-eslint/no-unsafe-argument */
 
 import {
   finalize,

src/compat/__tests__/when_media_source_open.test.ts

@@ -20,6 +20,7 @@
 /* eslint-disable @typescript-eslint/no-unsafe-call */
 /* eslint-disable @typescript-eslint/no-unsafe-assignment */
 /* eslint-disable @typescript-eslint/no-unsafe-return */
+/* eslint-disable @typescript-eslint/no-unsafe-argument */
 
 import {
   finalize,

src/compat/eme/custom_media_keys/index.ts

@@ -44,12 +44,12 @@ import {
 import getWebKitMediaKeysCallbacks from "./webkit_media_keys";
 import { WebKitMediaKeysConstructor } from "./webkit_media_keys_constructor";
 
-let requestMediaKeySystemAccess : null |
-                                  ((keyType : string,
-                                    config : MediaKeySystemConfiguration[])
-                                      => Observable<MediaKeySystemAccess |
-                                                    CustomMediaKeySystemAccess>)
-                                = null;
+/** Generic implementation of the navigator.requestMediaKeySystemAccess API. */
+type ICompatRequestMediaKeySystemAccessFn =
+  (keyType : string, config : MediaKeySystemConfiguration[]) =>
+    Observable<MediaKeySystemAccess | CustomMediaKeySystemAccess>;
+
+let requestMediaKeySystemAccess : null | ICompatRequestMediaKeySystemAccessFn = null;
 
 let _setMediaKeys :
 ((elt: HTMLMediaElement, mediaKeys: MediaKeys | ICustomMediaKeys | null) => void) =

src/compat/eme/custom_media_keys/old_webkit_media_keys.ts

@@ -94,12 +94,15 @@ class OldWebkitMediaKeySession
             const licenseTypedArray =
               license instanceof ArrayBuffer ? new Uint8Array(license) :
                                                license;
-            // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
-            const json = JSON.parse(utf8ToStr(licenseTypedArray));
             /* eslint-disable @typescript-eslint/no-unsafe-member-access */
+            /* eslint-disable @typescript-eslint/no-unsafe-argument */
+            /* eslint-disable @typescript-eslint/no-unsafe-assignment */
+            const json = JSON.parse(utf8ToStr(licenseTypedArray));
             const key = base64ToBytes(json.keys[0].k);
             const kid = base64ToBytes(json.keys[0].kid);
             /* eslint-enable @typescript-eslint/no-unsafe-member-access */
+            /* eslint-enable @typescript-eslint/no-unsafe-argument */
+            /* eslint-enable @typescript-eslint/no-unsafe-assignment */
             resolve(this._vid.webkitAddKey(this._key, key, kid, /* sessionId */ ""));
           } else {
             resolve(this._vid.webkitAddKey(this._key, license, null, /* sessionId */ ""));

src/compat/eme/load_session.ts

@@ -16,7 +16,7 @@
 
 import {
   defer as observableDefer,
-  mapTo,
+  map,
   mergeMap,
   Observable,
   of as observableOf,
@@ -66,6 +66,6 @@ export default function loadSession(
     return observableRace(
       observableTimer(EME_WAITING_DELAY_LOADED_SESSION_EMPTY_KEYSTATUSES),
       onKeyStatusesChange$(session)
-    ).pipe(take(1), mapTo(isLoaded));
+    ).pipe(take(1), map(() => isLoaded));
   }));
 }

src/compat/event_listeners.ts

@@ -29,7 +29,6 @@ import {
   fromEvent as observableFromEvent,
   interval as observableInterval,
   map,
-  mapTo,
   merge as observableMerge,
   of as observableOf,
   startWith,
@@ -269,7 +268,7 @@ function onPictureInPictureEvent$(
           }).pictureInPictureWindow ?? null,
         }))),
       observableFromEvent(mediaElement, "leavepictureinpicture")
-        .pipe(mapTo({ isEnabled: false, pipWindow: null }))
+        .pipe(map(() => ({ isEnabled: false, pipWindow: null })))
     ).pipe(startWith(initialState));
   });
 }

src/core/abr/representation_estimator.ts

@@ -44,6 +44,12 @@ import PendingRequestsStore from "./pending_requests_store";
 import RepresentationScoreCalculator from "./representation_score_calculator";
 import selectOptimalRepresentation from "./select_optimal_representation";
 
+// NOTE As of now (RxJS 7.4.0), RxJS defines `ignoreElements` default
+// first type parameter as `any` instead of the perfectly fine `unknown`,
+// leading to linter issues, as it forbids the usage of `any`.
+// This is why we're disabling the eslint rule.
+/* eslint-disable @typescript-eslint/no-unsafe-argument */
+
 /**
  * Adaptive BitRate estimate object.
  *

src/core/api/__tests__/option_utils.test.ts

@@ -20,6 +20,7 @@
 /* eslint-disable @typescript-eslint/no-unsafe-call */
 /* eslint-disable @typescript-eslint/no-unsafe-assignment */
 /* eslint-disable @typescript-eslint/no-unsafe-return */
+/* eslint-disable @typescript-eslint/no-unsafe-argument */
 /* eslint-disable @typescript-eslint/no-explicit-any */
 
 import config from "../../../config";

src/core/api/emit_seek_events.ts

@@ -18,11 +18,11 @@ import {
   defer as observableDefer,
   EMPTY,
   filter,
-  mapTo,
+  map,
   merge as observableMerge,
   Observable,
   startWith,
-  switchMapTo,
+  switchMap,
   take,
 } from "rxjs";
 import { IPlaybackObservation } from "./playback_observer";
@@ -47,13 +47,13 @@ export default function emitSeekEvents(
 
     const isSeeking$ = observation$.pipe(
       filter((observation : IPlaybackObservation) => observation.event === "seeking"),
-      mapTo("seeking" as const)
+      map(() => "seeking" as const)
     );
     const hasSeeked$ = isSeeking$.pipe(
-      switchMapTo(
+      switchMap(() =>
         observation$.pipe(
           filter((observation : IPlaybackObservation) => observation.event === "seeked"),
-          mapTo("seeked" as const),
+          map(() => "seeked" as const),
           take(1)))
     );
     const seekingEvents$ = observableMerge(isSeeking$, hasSeeked$);

src/core/api/playback_observer.ts

@@ -19,7 +19,6 @@ import {
   fromEvent as observableFromEvent,
   interval as observableInterval,
   map,
-  mapTo,
   merge as observableMerge,
   Observable,
   share,
@@ -245,15 +244,15 @@ export default class PlaybackObserver {
       const eventObs : Array< Observable< IPlaybackObserverEventType > > =
         SCANNED_MEDIA_ELEMENTS_EVENTS.map((eventName) =>
           observableFromEvent(this._mediaElement, eventName)
-            .pipe(mapTo(eventName)));
+            .pipe(map(() => eventName)));
 
       const interval = this._lowLatencyMode  ? SAMPLING_INTERVAL_LOW_LATENCY :
                        this._withMediaSource ? SAMPLING_INTERVAL_MEDIASOURCE :
                                                SAMPLING_INTERVAL_NO_MEDIASOURCE;
 
       const interval$ : Observable<"timeupdate"> =
         observableInterval(interval)
-          .pipe(mapTo("timeupdate"));
+          .pipe(map(() => "timeupdate"));
 
       return observableMerge(interval$, ...eventObs).pipe(
         map((event : IPlaybackObserverEventType) => {

src/core/api/public_api.ts

@@ -28,10 +28,8 @@ import {
   EMPTY,
   filter,
   map,
-  mapTo,
   merge as observableMerge,
   mergeMap,
-  mergeMapTo,
   Observable,
   of as observableOf,
   ReplaySubject,
@@ -41,7 +39,7 @@ import {
   startWith,
   Subject,
   Subscription,
-  switchMapTo,
+  switchMap,
   take,
   takeUntil,
 } from "rxjs";
@@ -1028,7 +1026,7 @@ class Player extends EventEmitter<IPublicAPIEvent> {
       observableOf(PLAYER_STATES.LOADING), // Begin with LOADING
 
       // LOADED as soon as the first "loaded" event is sent
-      loaded$.pipe(take(1), mapTo(PLAYER_STATES.LOADED)),
+      loaded$.pipe(take(1), map(() => PLAYER_STATES.LOADED)),
 
       observableMerge(
         loadedStateUpdates$
@@ -1040,10 +1038,10 @@ class Player extends EventEmitter<IPublicAPIEvent> {
 
         // when reloading
         reloading$.pipe(
-          switchMapTo(
+          switchMap(() =>
             loaded$.pipe(
               take(1), // wait for the next loaded event
-              mergeMapTo(loadedStateUpdates$), // to update the state as usual
+              mergeMap(() => loadedStateUpdates$), // to update the state as usual
               startWith(PLAYER_STATES.RELOADING) // Starts with "RELOADING" state
             )
           )
@@ -1074,7 +1072,7 @@ class Player extends EventEmitter<IPublicAPIEvent> {
 
     // Link "seeking" and "seeked" events (once the content is loaded)
     loaded$.pipe(
-      switchMapTo(emitSeekEvents(this.videoElement, observation$)),
+      switchMap(() => emitSeekEvents(this.videoElement, observation$)),
       takeUntil(stopContent$)
     ).subscribe((evt : "seeking" | "seeked") => {
       log.info(`API: Triggering "${evt}" event`);

src/core/eme/__tests__/__global__/init_data.test.ts

@@ -20,6 +20,7 @@
 /* eslint-disable @typescript-eslint/no-unsafe-call */
 /* eslint-disable @typescript-eslint/no-unsafe-assignment */
 /* eslint-disable @typescript-eslint/no-unsafe-return */
+/* eslint-disable @typescript-eslint/no-unsafe-argument */
 /* eslint-disable @typescript-eslint/restrict-template-expressions */
 /* eslint-disable @typescript-eslint/no-explicit-any */
 

src/core/eme/__tests__/__global__/media_key_system_access.test.ts

@@ -20,6 +20,7 @@
 /* eslint-disable @typescript-eslint/no-unsafe-call */
 /* eslint-disable @typescript-eslint/no-unsafe-assignment */
 /* eslint-disable @typescript-eslint/no-unsafe-return */
+/* eslint-disable @typescript-eslint/no-unsafe-argument */
 /* eslint-disable @typescript-eslint/no-explicit-any */
 
 import {

src/core/eme/__tests__/__global__/utils.ts

@@ -20,6 +20,7 @@
 /* eslint-disable @typescript-eslint/no-unsafe-call */
 /* eslint-disable @typescript-eslint/no-unsafe-assignment */
 /* eslint-disable @typescript-eslint/no-unsafe-return */
+/* eslint-disable @typescript-eslint/no-unsafe-argument */
 /* eslint-disable no-restricted-properties */
 
 import {

src/core/eme/clear_eme_session.ts

@@ -48,6 +48,11 @@ export default function clearEMESession(
     {
       log.info("EME: closing all current sessions.");
       return currentState.loadedSessionsStore.closeAllSessions()
+        // NOTE As of now (RxJS 7.4.0), RxJS defines `ignoreElements` default
+        // first type parameter as `any` instead of the perfectly fine `unknown`,
+        // leading to linter issues, as it forbids the usage of `any`.
+        // This is why we're disabling the eslint rule.
+        /* eslint-disable-next-line @typescript-eslint/no-unsafe-argument */
         .pipe(ignoreElements());
     }
     log.info("EME: Nothing to clear. Returning right away. No state =",

src/core/eme/dispose_media_keys.ts

@@ -16,7 +16,7 @@
 
 import {
   defer as observableDefer,
-  mergeMapTo,
+  mergeMap,
   Observable,
   of as observableOf,
 } from "rxjs";
@@ -41,6 +41,6 @@ export default function disposeMediaKeys(
     const { loadedSessionsStore } = currentState;
     MediaKeysInfosStore.clearState(mediaElement);
     return loadedSessionsStore.closeAllSessions()
-      .pipe(mergeMapTo(setMediaKeys(mediaElement, null)));
+      .pipe(mergeMap(() => setMediaKeys(mediaElement, null)));
   });
 }

src/core/eme/session_events_listener.ts

@@ -22,7 +22,6 @@ import {
   EMPTY,
   identity,
   map,
-  mapTo,
   merge as observableMerge,
   mergeMap,
   Observable,
@@ -287,8 +286,8 @@ function updateSessionWithMessage(
       throw new EncryptedMediaError("KEY_UPDATE_ERROR", reason);
     }),
     tap(() => { log.info("EME: MediaKeySession update succeeded."); }),
-    mapTo({ type: "session-updated" as const,
-            value: { session, license: message, initializationData } })
+    map(() => ({ type: "session-updated" as const,
+                 value: { session, license: message, initializationData } }))
   );
 }