Add rxjs/recommend eslint rules (#2724)

We will probably want to tweak these as we get more used to them.

.eslintrc.cjs

@@ -8,12 +8,13 @@ Please see LICENSE in the repository root for full details.
 `;
 
 module.exports = {
-  plugins: ["matrix-org"],
+  plugins: ["matrix-org", "rxjs"],
   extends: [
     "plugin:matrix-org/react",
     "plugin:matrix-org/a11y",
     "plugin:matrix-org/typescript",
     "prettier",
+    "plugin:rxjs/recommended",
   ],
   parserOptions: {
     ecmaVersion: "latest",

package.json

@@ -73,6 +73,7 @@
     "eslint-plugin-matrix-org": "^1.2.1",
     "eslint-plugin-react": "^7.29.4",
     "eslint-plugin-react-hooks": "^5.0.0",
+    "eslint-plugin-rxjs": "^5.0.3",
     "eslint-plugin-unicorn": "^56.0.0",
     "global-jsdom": "^25.0.0",
     "history": "^4.0.0",

src/state/MediaViewModel.ts

@@ -245,7 +245,10 @@ abstract class BaseMediaViewModel extends ViewModel {
         encryptionSystem.kind !== E2eeType.NONE &&
         (a.publication?.isEncrypted === false ||
           v.publication?.isEncrypted === false),
-    ).pipe(distinctUntilChanged(), shareReplay(1));
+    ).pipe(
+      distinctUntilChanged(),
+      shareReplay({ bufferSize: 1, refCount: false }),
+    );
 
     if (participant.isLocal || encryptionSystem.kind === E2eeType.NONE) {
       this.encryptionStatus = of(EncryptionStatus.Okay).pipe(

src/state/ObservableScope.ts

@@ -32,7 +32,11 @@ export class ObservableScope {
   }
 
   private readonly stateImpl: MonoTypeOperator = (o) =>
-    o.pipe(this.bind(), distinctUntilChanged(), shareReplay(1));
+    o.pipe(
+      this.bind(),
+      distinctUntilChanged(),
+      shareReplay({ bufferSize: 1, refCount: false }),
+    );
 
   /**
    * Transforms an Observable into a hot state Observable which replays its