mancala/apps/backend/tests/game/FakeRtmt.ts

import { AuthUser } from "../../src/auth";
import { OnClientConnectionChange, OnMessage, RTMT } from "../../src/rtmt/rtmt";

export type SentMessage = { clientID: string, channel: string, message: any };

// In-memory RTMT: tests connect users, send messages as them and inspect what the server sent back.
export class FakeRtmt implements RTMT {
    readonly sent: SentMessage[] = [];
    private readonly listeners = new Map<string, OnMessage>();
    private readonly online = new Map<string, AuthUser>();
    private onConnectionChange?: OnClientConnectionChange;

    connect(user: AuthUser) {
        this.online.set(user.id, user);
        this.onConnectionChange?.(user.id, true);
    }

    disconnect(userId: string) {
        this.online.delete(userId);
        this.onConnectionChange?.(userId, false);
    }

    receive(userId: string, channel: string, message: Object = {}) {
        const listener = this.listeners.get(channel);
        if (!listener) throw new Error(`No listener for ${channel}`);
        listener(userId, message);
    }

    messagesTo(userId: string, channel: string): any[] {
        return this.sent.filter((m) => m.clientID === userId && m.channel === channel).map((m) => m.message);
    }

    sendMessage(clientID: string, channel: string, message: Object) {
        // Copy, like serialising over the wire would.
        this.sent.push({ clientID, channel, message: JSON.parse(JSON.stringify(message)) });
    }

    listenMessage(channel: string, callback: OnMessage) {
        this.listeners.set(channel, callback);
    }

    isClientOnline(clientID: string): boolean {
        return this.online.has(clientID);
    }

    getUser(clientID: string): AuthUser | undefined {
        return this.online.get(clientID);
    }

    listenOnClientConnectionChange(onUserConnectionChange: OnClientConnectionChange): void {
        this.onConnectionChange = onUserConnectionChange;
    }
}