refactor: standardize Pusher event handling with REALTIME_PUSHER_EVENTS

- Updated comment action and components to utilize REALTIME_PUSHER_EVENTS for event names, enhancing consistency across the codebase.
- Refactored the listenChannel function to improve event binding and unbinding logic, ensuring better maintainability.
- Adjusted notification handling in the RealtimeProvider to align with the new event structure.

Author: kingRayhan

src/backend/services/comment.action.ts

@@ -10,7 +10,10 @@ import { and, eq, inArray } from "sqlkit";
 import { CommentPresentation } from "../models/domain-models";
 import { inngest } from "@/lib/inngest";
 import { assertCommentResourceExists } from "./notifications.payload";
-import { publishMessage } from "@/lib/pusher/pusher.server";
+import {
+  publishMessage,
+  REALTIME_PUSHER_EVENTS,
+} from "@/lib/pusher/pusher.server";
 
 const sql = String.raw;
 
@@ -71,7 +74,7 @@ export const createMyComment = async (
 
   void publishMessage(
     `resource.${resource_type}.${resource_id}`,
-    "comment.created",
+    REALTIME_PUSHER_EVENTS.COMMENT_CREATED,
     { scope: "comments" },
   );
 
@@ -106,7 +109,7 @@ export const updateMyComment = async (
 
     void publishMessage(
       `resource.${existing.resource_type}.${existing.resource_id}`,
-      "comment.updated",
+      REALTIME_PUSHER_EVENTS.COMMENT_UPDATED,
       { scope: "comments" },
     );
 
@@ -164,7 +167,7 @@ export const deleteMyComment = async (
 
     void publishMessage(
       `resource.${root.resource_type}.${root.resource_id}`,
-      "comment.deleted",
+      REALTIME_PUSHER_EVENTS.COMMENT_DELETED,
       { scope: "comments" },
     );
 

src/components/comment-section.tsx

@@ -38,7 +38,10 @@ import { Button } from "./ui/button";
 import { Skeleton } from "./ui/skeleton";
 import { Textarea } from "./ui/textarea";
 import getFileUrl from "@/utils/getFileUrl";
-import { listenChannel } from "@/lib/pusher/pusher.client";
+import {
+  listenChannel,
+  REALTIME_PUSHER_EVENTS,
+} from "@/lib/pusher/pusher.client";
 
 const Context = React.createContext<
   { mutatingId?: string; setMutatingId: (id?: string) => void } | undefined
@@ -166,9 +169,9 @@ export const CommentSection = (props: {
       });
     };
     return listenChannel(channelName, {
-      "comment.created": invalidate,
-      "comment.updated": invalidate,
-      "comment.deleted": invalidate,
+      [REALTIME_PUSHER_EVENTS.COMMENT_CREATED]: invalidate,
+      [REALTIME_PUSHER_EVENTS.COMMENT_UPDATED]: invalidate,
+      [REALTIME_PUSHER_EVENTS.COMMENT_DELETED]: invalidate,
     });
   }, [props.resource_id, props.resource_type, queryClient]);
 

src/components/providers/RealtimeProvider.tsx

@@ -1,6 +1,9 @@
 "use client";
 
-import { listenChannel } from "@/lib/pusher/pusher.client";
+import {
+  listenChannel,
+  REALTIME_PUSHER_EVENTS,
+} from "@/lib/pusher/pusher.client";
 import { useSession } from "@/store/session.atom";
 import { useQueryClient } from "@tanstack/react-query";
 import React, { PropsWithChildren, useEffect } from "react";
@@ -35,7 +38,7 @@ export function RealtimeProvider({ children }: PropsWithChildren) {
       });
     };
     return listenChannel(channelName, {
-      "notification.new": invalidate,
+      [REALTIME_PUSHER_EVENTS.NOTIFICATION_NEW]: invalidate,
     });
   }, [userId, queryClient]);
 

src/lib/inngest.ts

@@ -7,7 +7,10 @@ import {
 import { persistenceRepository } from "@/backend/persistence/persistence-repositories";
 import { ActionException } from "@/backend/services/RepositoryException";
 import { buildPersistableNotification } from "@/backend/services/notifications.payload";
-import { publishMessage } from "@/lib/pusher/pusher.server";
+import {
+  publishMessage,
+  REALTIME_PUSHER_EVENTS,
+} from "@/lib/pusher/pusher.server";
 import { deleteExpiredArticles } from "@/backend/services/article-cleanup-service";
 
 const notificationPayloadSchema = z.object({
@@ -191,9 +194,11 @@ export const persistNotificationFn = inngest.createFunction(
 
     // Broadcast a lightweight signal so the recipient's browser can invalidate
     // its TanStack Query caches without polling.
-    await publishMessage(`private-user.${data.recipient_id}`, "notification.new", {
-      scope: "notifications",
-    });
+    await publishMessage(
+      `private-user.${data.recipient_id}`,
+      REALTIME_PUSHER_EVENTS.NOTIFICATION_NEW,
+      { scope: "notifications" },
+    );
 
     return { success: true };
   },

src/lib/pusher/pusher.client.ts

@@ -1,5 +1,15 @@
 import Pusher from "pusher-js";
 import { env } from "@/env";
+import type {
+  RealtimeListenHandlers,
+  RealtimePusherEvent,
+} from "./realtime-events";
+
+export {
+  REALTIME_PUSHER_EVENTS,
+  type RealtimeListenHandlers,
+  type RealtimePusherEvent,
+} from "./realtime-events";
 
 let _pusherClient: Pusher | null = null;
 
@@ -23,25 +33,25 @@ function getPusherClient(): Pusher | null {
   return _pusherClient;
 }
 
-type EventHandlers = Record<string, () => void>;
-
 export function listenChannel(
   channel: string,
-  handlers: EventHandlers,
+  handlers: RealtimeListenHandlers,
 ): () => void {
   const pusher = getPusherClient();
   if (!pusher) {
     return () => {};
   }
 
   const ch = pusher.subscribe(channel);
-  for (const [event, fn] of Object.entries(handlers)) {
-    ch.bind(event, fn);
+  for (const event of Object.keys(handlers) as RealtimePusherEvent[]) {
+    const fn = handlers[event];
+    if (fn) ch.bind(event, fn);
   }
 
   return () => {
-    for (const [event, fn] of Object.entries(handlers)) {
-      ch.unbind(event, fn);
+    for (const event of Object.keys(handlers) as RealtimePusherEvent[]) {
+      const fn = handlers[event];
+      if (fn) ch.unbind(event, fn);
     }
     pusher.unsubscribe(channel);
   };

src/lib/pusher/pusher.server.ts

@@ -1,5 +1,11 @@
 import Pusher from "pusher";
 import { env } from "@/env";
+import type { RealtimePusherEvent } from "./realtime-events";
+
+export {
+  REALTIME_PUSHER_EVENTS,
+  type RealtimePusherEvent,
+} from "./realtime-events";
 
 /**
  * Lazy singleton for the server-side Pusher/Soketi client.
@@ -28,7 +34,7 @@ export const pusherServer = createPusherServer();
  */
 export async function publishMessage(
   channel: string,
-  event: "comment.created" | "comment.updated" | "comment.deleted",
+  event: RealtimePusherEvent,
   data: Record<string, unknown> = {},
 ): Promise<void> {
   console.log(`

src/lib/pusher/realtime-events.ts

@@ -0,0 +1,18 @@
+/**
+ * Canonical Pusher event names for app realtime (invalidate / refetch signals).
+ * Extend here so client listeners and server triggers stay aligned.
+ */
+export const REALTIME_PUSHER_EVENTS = {
+  NOTIFICATION_NEW: "notification.new",
+  COMMENT_CREATED: "comment.created",
+  COMMENT_UPDATED: "comment.updated",
+  COMMENT_DELETED: "comment.deleted",
+} as const;
+
+export type RealtimePusherEvent =
+  (typeof REALTIME_PUSHER_EVENTS)[keyof typeof REALTIME_PUSHER_EVENTS];
+
+/** Handlers object for `listenChannel`: only known event names, each optional. */
+export type RealtimeListenHandlers = {
+  [K in RealtimePusherEvent]?: () => void;
+};