같은 파일의 두 세션 연결하기

npm install @nestjs/websockets@11 @nestjs/platform-socket.io@11 socket.io@4

import {
  OnGatewayInit, WebSocketGateway, SubscribeMessage,
  MessageBody, ConnectedSocket,
} from '@nestjs/websockets';
import { JwtService } from '@nestjs/jwt';
import { Server, Socket } from 'socket.io';
import { AuthService } from '../auth/auth.service';
import { ProjectService } from '../project/project.service';

interface FileRequest { projectId: string; fileId: string; }
interface ChangeRequest extends FileRequest { changes: string; }

@WebSocketGateway({
  cors: { origin: 'http://localhost:5173' },
})
export class RealtimeGateway implements OnGatewayInit {
  constructor(
    private readonly jwt: JwtService,
    private readonly auth: AuthService,
    private readonly projects: ProjectService,
  ) {}

  afterInit(server: Server) {
    server.use(async (client, next) => {
      try {
        const token = client.handshake.auth.token;
        const payload = await this.jwt.verifyAsync<{ sub: string }>(token);
        const user = await this.auth.validateUser(payload.sub);
        if (!user) throw new Error('Unknown user');
        client.data.userId = user.id;
        next();
      } catch {
        next(new Error('Login is required.'));
      }
    });
  }

  private room(fileId: string) { return `file:${fileId}`; }

  private async checkFile(client: Socket, data: FileRequest) {
    const payload = await this.jwt.verifyAsync<{ sub: string }>(
      client.handshake.auth.token,
    );
    if (payload.sub !== client.data.userId) throw new Error('Invalid user');
    const uuid = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i;
    if (!data || !uuid.test(data.projectId) || !uuid.test(data.fileId)) {
      throw new Error('Invalid file ID');
    }
    const file = await this.projects.findFileById(data.fileId, client.data.userId);
    if (file.projectId !== data.projectId) throw new Error('Wrong project');
    return file;
  }

  @SubscribeMessage('join_file')
  async join(@ConnectedSocket() client: Socket, @MessageBody() data: FileRequest) {
    try {
      const file = await this.checkFile(client, data);
      if (client.data.fileId) await client.leave(this.room(client.data.fileId));
      await client.join(this.room(file.id));
      client.data.fileId = file.id;
      return { ok: true, fileId: file.id, content: file.content ?? '' };
    } catch {
      return { ok: false, message: 'Unable to open this file.' };
    }
  }

  @SubscribeMessage('leave_file')
  async leave(@ConnectedSocket() client: Socket) {
    if (client.data.fileId) await client.leave(this.room(client.data.fileId));
    client.data.fileId = undefined;
    return { ok: true };
  }

  @SubscribeMessage('code_change')
  async change(@ConnectedSocket() client: Socket, @MessageBody() data: ChangeRequest) {
    try {
      await this.checkFile(client, data);
      if (client.data.fileId !== data.fileId || !client.rooms.has(this.room(data.fileId))) {
        return { ok: false, message: 'Join the file before editing.' };
      }
      if (typeof data.changes !== 'string' || data.changes.length > 200_000) {
        return { ok: false, message: 'Invalid content or content too long.' };
      }
      const file = await this.projects.updateFileContent(
        data.fileId, client.data.userId, data.changes,
      );
      client.to(this.room(file.id)).emit('code_update', {
        fileId: file.id, userId: client.data.userId, changes: file.content,
      });
      return { ok: true, fileId: file.id };
    } catch {
      return { ok: false, message: 'Save failed. Check login, owner and server.' };
    }
  }
}

import { Module } from '@nestjs/common';
import { AuthModule } from '../auth/auth.module';
import { ProjectModule } from '../project/project.module';
import { RealtimeGateway } from './realtime.gateway';

@Module({
  imports: [AuthModule, ProjectModule],
  providers: [RealtimeGateway],
})
export class RealtimeModule {}

import { RealtimeModule } from './realtime/realtime.module';