From 77853e708cfbe9f0d626fb8aa948eefac96be0ad Mon Sep 17 00:00:00 2001
From: Thibault Duplessis <t@lichess.org>
Date: Wed, 30 Oct 2024 15:00:23 +0100
Subject: [PATCH] make common/pubsub a class so that multiple can be made

no functional change intended (tm)
---
 ui/common/src/pubsub.ts | 59 +++++++++++++++++++----------------------
 1 file changed, 28 insertions(+), 31 deletions(-)

diff --git a/ui/common/src/pubsub.ts b/ui/common/src/pubsub.ts
index f257443f85d0..9021532f26e0 100644
--- a/ui/common/src/pubsub.ts
+++ b/ui/common/src/pubsub.ts
@@ -60,52 +60,49 @@ export type PubsubOneTimeEvent = 'dialog.polyfill' | 'socket.hasConnected';
 
 export type PubsubCallback = (...data: any[]) => void;
 
-export interface Pubsub {
-  on(msg: PubsubEvent, f: PubsubCallback): void;
-  off(msg: PubsubEvent, f: PubsubCallback): void;
-  emit(msg: PubsubEvent, ...args: any[]): void;
+export class Pubsub {
+  private allSubs: Map<PubsubEvent, Set<() => void>> = new Map();
+  private oneTimeEvents: Map<PubsubOneTimeEvent, OneTimeHandler> = new Map();
 
-  after(event: PubsubOneTimeEvent): Promise<void>;
-  complete(event: PubsubOneTimeEvent): void;
-  past(event: PubsubOneTimeEvent): boolean;
-}
-
-export const pubsub: Pubsub = {
-  on(name: PubsubEvent, cb) {
-    const subs = allSubs.get(name);
+  on(name: PubsubEvent, cb: PubsubCallback): void {
+    const subs = this.allSubs.get(name);
     if (subs) subs.add(cb);
-    else allSubs.set(name, new Set([cb]));
-  },
-  off(name: PubsubEvent, cb) {
-    allSubs.get(name)?.delete(cb);
-  },
-  emit(name: PubsubEvent, ...args: any[]) {
-    for (const fn of allSubs.get(name) || []) fn.apply(null, args);
-  },
+    else this.allSubs.set(name, new Set([cb]));
+  }
+
+  off(name: PubsubEvent, cb: PubsubCallback): void {
+    this.allSubs.get(name)?.delete(cb);
+  }
+
+  emit(name: PubsubEvent, ...args: any[]): void {
+    for (const fn of this.allSubs.get(name) || []) fn.apply(null, args);
+  }
+
   after(event: PubsubOneTimeEvent): Promise<void> {
-    const found = oneTimeEvents.get(event);
+    const found = this.oneTimeEvents.get(event);
     if (found) return found.promise;
 
     const handler = {} as OneTimeHandler;
     handler.promise = new Promise<void>(resolve => (handler!.resolve = resolve));
-    oneTimeEvents.set(event, handler);
+    this.oneTimeEvents.set(event, handler);
 
     return handler.promise;
-  },
+  }
+
   complete(event: PubsubOneTimeEvent): void {
-    const found = oneTimeEvents.get(event);
+    const found = this.oneTimeEvents.get(event);
     if (found) {
       found.resolve?.();
       found.resolve = undefined;
-    } else oneTimeEvents.set(event, { promise: Promise.resolve() });
-  },
+    } else this.oneTimeEvents.set(event, { promise: Promise.resolve() });
+  }
+
   past(event: PubsubOneTimeEvent): boolean {
-    return oneTimeEvents.has(event) && !oneTimeEvents.get(event)?.resolve;
-  },
-};
+    return this.oneTimeEvents.has(event) && !this.oneTimeEvents.get(event)?.resolve;
+  }
+}
 
-const allSubs: Map<PubsubEvent, Set<() => void>> = new Map();
-const oneTimeEvents: Map<PubsubOneTimeEvent, OneTimeHandler> = new Map();
+export const pubsub: Pubsub = new Pubsub();
 
 interface OneTimeHandler {
   promise: Promise<void>;