refactor: replace all hardcoded magic strings with typed constants (Close #334)

src/auth/guards/jwt-auth.guard.ts

@@ -1,5 +1,6 @@
 import { Injectable } from '@nestjs/common';
 import { AuthGuard } from '@nestjs/passport';
+import { AUTH_STRATEGY } from '../../common/constants/auth.constants';
 
 @Injectable()
-export class JwtAuthGuard extends AuthGuard('jwt') {}
+export class JwtAuthGuard extends AuthGuard(AUTH_STRATEGY.JWT) {}

src/backup/backup.module.ts

@@ -3,6 +3,7 @@ import { TypeOrmModule } from '@nestjs/typeorm';
 import { BullModule } from '@nestjs/bull';
 import { ConfigModule } from '@nestjs/config';
 import { ScheduleModule } from '@nestjs/schedule';
+import { QUEUE_NAMES } from '../common/constants/queue.constants';
 
 // Entities
 import { BackupRecord } from './entities/backup-record.entity';
@@ -31,7 +32,7 @@ import { MonitoringModule } from '../monitoring/monitoring.module';
     ScheduleModule.forRoot(),
     TypeOrmModule.forFeature([BackupRecord, RecoveryTest]),
     BullModule.registerQueue({
-      name: 'backup-processing',
+      name: QUEUE_NAMES.BACKUP_PROCESSING,
     }),
     MediaModule, // For FileStorageService
     MonitoringModule, // For AlertingService and MetricsCollectionService

src/backup/backup.service.ts

@@ -3,6 +3,7 @@ import { InjectRepository } from '@nestjs/typeorm';
 import { Repository, LessThan } from 'typeorm';
 import { InjectQueue } from '@nestjs/bull';
 import { Queue } from 'bull';
+import { QUEUE_NAMES, JOB_NAMES } from './../../common/constants/queue.constants';
 import { ConfigService } from '@nestjs/config';
 import { Cron } from '@nestjs/schedule';
 import { BackupRecord } from './entities/backup-record.entity';
@@ -29,7 +30,7 @@ export class BackupService {
   constructor(
     @InjectRepository(BackupRecord)
     private readonly backupRepository: Repository<BackupRecord>,
-    @InjectQueue('backup-processing')
+    @InjectQueue(QUEUE_NAMES.BACKUP_PROCESSING)
     private readonly backupQueue: Queue,
     private readonly configService: ConfigService,
     private readonly alertingService: AlertingService,
@@ -103,7 +104,7 @@ export class BackupService {
 
         // Queue backup job
         await this.backupQueue.add(
-          'create-backup',
+          JOB_NAMES.CREATE_BACKUP,
           {
             backupRecordId: backupRecord.id,
             backupType: BackupType.FULL,
@@ -157,7 +158,7 @@ export class BackupService {
 
         for (const backup of expiredBackups) {
           await this.backupQueue.add(
-            'delete-backup',
+            JOB_NAMES.DELETE_BACKUP,
             { backupRecordId: backup.id },
             {
               attempts: 3,

src/backup/processing/backup-queue.processor.ts

@@ -1,6 +1,7 @@
 import { Process, Processor } from '@nestjs/bull';
 import { Logger } from '@nestjs/common';
 import { Job } from 'bull';
+import { QUEUE_NAMES, JOB_NAMES } from '../../common/constants/queue.constants';
 import { InjectRepository } from '@nestjs/typeorm';
 import { Repository } from 'typeorm';
 import { ConfigService } from '@nestjs/config';
@@ -24,7 +25,7 @@ import { S3Client, CopyObjectCommand, DeleteObjectCommand } from '@aws-sdk/clien
 const execAsync = promisify(exec);
 const MAX_RETRIES = 3;
 
-@Processor('backup-processing')
+@Processor(QUEUE_NAMES.BACKUP_PROCESSING)
 export class BackupQueueProcessor {
   private readonly logger = new Logger(BackupQueueProcessor.name);
   private readonly kmsClient: KMSClient;
@@ -57,7 +58,7 @@ export class BackupQueueProcessor {
     });
   }
 
-  @Process('create-backup')
+  @Process(JOB_NAMES.CREATE_BACKUP)
   async handleCreateBackup(job: Job<BackupJobData>) {
     const { backupRecordId, databaseName } = job.data;
     this.logger.log(`Processing backup creation for: ${backupRecordId}`);
@@ -136,7 +137,7 @@ export class BackupQueueProcessor {
 
       // Queue verification job
       await (job.queue as any).add(
-        'verify-backup',
+        JOB_NAMES.VERIFY_BACKUP,
         { backupRecordId, storageKey: encryptedKey },
         {
           attempts: 3,
@@ -151,7 +152,7 @@ export class BackupQueueProcessor {
     }
   }
 
-  @Process('verify-backup')
+  @Process(JOB_NAMES.VERIFY_BACKUP)
   async handleVerifyBackup(job: Job<VerificationJobData>) {
     const { backupRecordId } = job.data;
     this.logger.log(`Verifying backup integrity: ${backupRecordId}`);
@@ -177,13 +178,13 @@ export class BackupQueueProcessor {
     }
   }
 
-  @Process('recovery-test')
+  @Process(JOB_NAMES.RECOVERY_TEST)
   async handleRecoveryTest(_job: Job<RecoveryTestJobData>) {
     this.logger.log(`Recovery test processing handled by RecoveryTestingService`);
     // Delegated to RecoveryTestingService.executeRecoveryTest()
   }
 
-  @Process('delete-backup')
+  @Process(JOB_NAMES.DELETE_BACKUP)
   async handleDeleteBackup(job: Job<{ backupRecordId: string }>) {
     const { backupRecordId } = job.data;
     this.logger.log(`Deleting expired backup: ${backupRecordId}`);

src/backup/testing/recovery-testing.service.ts

@@ -3,6 +3,7 @@ import { InjectRepository } from '@nestjs/typeorm';
 import { Repository } from 'typeorm';
 import { InjectQueue } from '@nestjs/bull';
 import { Queue } from 'bull';
+import { QUEUE_NAMES, JOB_NAMES } from '../../common/constants/queue.constants';
 import { ConfigService } from '@nestjs/config';
 import { RecoveryTest } from '../entities/recovery-test.entity';
 import { RecoveryTestStatus } from '../enums/recovery-test-status.enum';
@@ -27,7 +28,7 @@ export class RecoveryTestingService {
   constructor(
     @InjectRepository(RecoveryTest)
     private readonly recoveryTestRepository: Repository<RecoveryTest>,
-    @InjectQueue('backup-processing')
+    @InjectQueue(QUEUE_NAMES.BACKUP_PROCESSING)
     private readonly backupQueue: Queue,
     private readonly backupService: BackupService,
     private readonly fileStorageService: FileStorageService,
@@ -59,7 +60,7 @@ export class RecoveryTestingService {
 
     // Queue recovery test job
     await this.backupQueue.add(
-      'recovery-test',
+      JOB_NAMES.RECOVERY_TEST,
       {
         recoveryTestId: recoveryTest.id,
         backupRecordId: backupId,

src/caching/cache-management.controller.ts

@@ -16,14 +16,13 @@ import { CacheInvalidationService } from './invalidation/invalidation.service';
 import { CacheWarmingService } from './warming/cache-warming.service';
 import { CacheStrategiesService } from './strategies/cache-strategies.service';
 import { RolesGuard } from '../common/guards/roles.guard';
-import { Roles } from '../common/decorators/roles.decorator';
-// import { Role } from '../common/decorators/roles.decorator';
+import { Roles, Role } from '../common/decorators/roles.decorator';
 
 @ApiTags('Cache Management')
 @ApiBearerAuth()
 @Controller('cache')
 @UseGuards(RolesGuard)
-@Roles('admin')
+@Roles(Role.ADMIN)
 export class CacheManagementController {
   constructor(
     private readonly cachingService: CachingService,

src/caching/caching.constants.ts

@@ -20,6 +20,8 @@ export const CACHE_PREFIXES = {
   POPULAR: 'cache:popular',
   ENROLLMENT: 'cache:enrollment',
   FEATURED: 'cache:featured',
+  SYSTEM_CONFIG: 'cache:system:config',
+  USERS_LIST: 'cache:users:list',
 } as const;
 
 export const CACHE_EVENTS = {
@@ -30,4 +32,6 @@ export const CACHE_EVENTS = {
   ENROLLMENT_CREATED: 'cache.enrollment.created',
   ENROLLMENT_UPDATED: 'cache.enrollment.updated',
   SEARCH_INDEX_UPDATED: 'cache.search.updated',
+  CACHE_INVALIDATED: 'cache.invalidated',
+  CACHE_PURGED: 'cache.purged',
 } as const;

src/caching/warming/cache-warming.service.ts

@@ -219,7 +219,7 @@ export class CacheWarmingService implements OnModuleInit, OnModuleDestroy {
   private async warmSystemConfig(): Promise<void> {
     this.logger.debug('Warming system configuration...');
 
-    const configKey = 'cache:system:config';
+    const configKey = CACHE_PREFIXES.SYSTEM_CONFIG;
 
     const configData = {
       version: this.configService.get<string>('npm_package_version') || '1.0.0',

src/collaboration/constants/collaboration-events.constants.ts

@@ -0,0 +1,25 @@
+export const COLLABORATION_EVENTS = {
+  // Inbound WebSocket messages
+  JOIN_SESSION: 'join-session',
+  COLLABORATIVE_OPERATION: 'collaborative-operation',
+  REQUEST_SYNC: 'request-sync',
+  RESOLVE_CONFLICT: 'resolve-conflict',
+
+  // Outbound WebSocket messages
+  USER_JOINED: 'user-joined',
+  SESSION_STATE: 'session-state',
+  OPERATION_APPLIED: 'operation-applied',
+  FULL_SYNC: 'full-sync',
+  CONFLICT_RESOLVED: 'conflict-resolved',
+} as const;
+
+export const NOTIFICATION_GATEWAY_EVENTS = {
+  SUBSCRIBE: 'subscribe',
+  NOTIFICATION: 'notification',
+  BROADCAST_NOTIFICATION: 'broadcast_notification',
+  SUBSCRIBE_NOTIFICATIONS: 'subscribe_notifications',
+} as const;
+
+export const MESSAGING_GATEWAY_EVENTS = {
+  SEND_MESSAGE: 'send_message',
+} as const;

src/collaboration/gateway/collaboration.gateway.ts

@@ -8,6 +8,7 @@ import {
   MessageBody,
   ConnectedSocket,
 } from '@nestjs/websockets';
+import { COLLABORATION_EVENTS } from '../constants/collaboration-events.constants';
 import { Server, Socket } from 'socket.io';
 import { Logger, UseGuards } from '@nestjs/common';
 import { CollaborationService } from '../collaboration.service';
@@ -75,7 +76,7 @@ export class CollaborationGateway
     // Remove client from any active sessions
   }
 
-  @SubscribeMessage('join-session')
+  @SubscribeMessage(COLLABORATION_EVENTS.JOIN_SESSION)
   async handleJoinSession(
     @MessageBody() data: { sessionId: string; userId: string; resourceType: string },
     @ConnectedSocket() client: Socket,
@@ -122,10 +123,10 @@ export class CollaborationGateway
       }
 
       // Notify other users in the session
-      client.to(sessionId).emit('user-joined', { userId, sessionId });
+      client.to(sessionId).emit(COLLABORATION_EVENTS.USER_JOINED, { userId, sessionId });
 
       // Send current resource state to the joining user
-      client.emit('session-state', {
+      client.emit(COLLABORATION_EVENTS.SESSION_STATE, {
         sessionId,
         resourceType,
         resource,
@@ -139,7 +140,7 @@ export class CollaborationGateway
     }
   }
 
-  @SubscribeMessage('collaborative-operation')
+  @SubscribeMessage(COLLABORATION_EVENTS.COLLABORATIVE_OPERATION)
   async handleCollaborativeOperation(
     @MessageBody() operation: CollaborativeOperation,
     @ConnectedSocket() client: Socket,
@@ -175,7 +176,7 @@ export class CollaborationGateway
       });
 
       // Broadcast the operation to all other clients in the session
-      client.to(sessionId).emit('operation-applied', {
+      client.to(sessionId).emit(COLLABORATION_EVENTS.OPERATION_APPLIED, {
         operation: opData,
         userId,
         timestamp: Date.now(),
@@ -189,7 +190,7 @@ export class CollaborationGateway
     }
   }
 
-  @SubscribeMessage('request-sync')
+  @SubscribeMessage(COLLABORATION_EVENTS.REQUEST_SYNC)
   async handleSyncRequest(
     @MessageBody() data: { sessionId: string; userId: string },
     @ConnectedSocket() client: Socket,
@@ -207,7 +208,7 @@ export class CollaborationGateway
       const document = await this.sharedDocumentService.getDocument(sessionId);
       const whiteboard = await this.whiteboardService.getWhiteboard(sessionId);
 
-      client.emit('full-sync', {
+      client.emit(COLLABORATION_EVENTS.FULL_SYNC, {
         sessionId,
         document: document || null,
         whiteboard: whiteboard || null,
@@ -218,7 +219,7 @@ export class CollaborationGateway
     }
   }
 
-  @SubscribeMessage('resolve-conflict')
+  @SubscribeMessage(COLLABORATION_EVENTS.RESOLVE_CONFLICT)
   async handleConflictResolution(
     @MessageBody()
     data: { sessionId: string; userId: string; resourceType: string; operations: any[] },
@@ -246,7 +247,7 @@ export class CollaborationGateway
       }
 
       // Broadcast resolved state to all clients
-      this.server.to(sessionId).emit('conflict-resolved', {
+      this.server.to(sessionId).emit(COLLABORATION_EVENTS.CONFLICT_RESOLVED, {
         sessionId,
         resourceType,
         resolvedState: result,

src/common/constants/auth.constants.ts

@@ -0,0 +1,3 @@
+export const AUTH_STRATEGY = {
+  JWT: 'jwt',
+} as const;

src/common/constants/event.constants.ts

@@ -0,0 +1,31 @@
+export const APP_EVENTS = {
+  // Data sync events
+  DATA_UPDATED: 'data.updated',
+
+  // Cache events
+  CACHE_INVALIDATED: 'cache.invalidated',
+  CACHE_PURGED: 'cache.purged',
+
+  // Data integrity events
+  DATA_CONSISTENCY_SCHEDULED: 'data.consistency.scheduled',
+  DATA_INTEGRITY_VIOLATION: 'data.integrity.violation',
+
+  // User events
+  USER_SIGNUP: 'user.signup',
+  USER_ADD_TAG: 'user.addTag',
+  USER_REMOVE_TAG: 'user.removeTag',
+
+  // Course events
+  COURSE_ENROLLED: 'course.enrolled',
+  COURSE_COMPLETED: 'course.completed',
+
+  // Payment events
+  PAYMENT_COMPLETED: 'payment.completed',
+
+  // Segment events
+  SEGMENT_ADD_USER: 'segment.addUser',
+
+  // Notification events
+  NOTIFICATION_SEND: 'notification.send',
+  NOTIFICATION_TEMPLATE_SEND: 'notification.template.send',
+} as const;

src/common/constants/queue.constants.ts

@@ -0,0 +1,42 @@
+export const QUEUE_NAMES = {
+  EMAIL: 'email',
+  EMAIL_MARKETING: 'email-marketing',
+  SYNC_TASKS: 'sync-tasks',
+  BACKUP_PROCESSING: 'backup-processing',
+  MESSAGE_QUEUE: 'message-queue',
+  MEDIA_PROCESSING: 'media-processing',
+  DEFAULT: 'default',
+  USER_DATA_EXPORT: 'user-data-export',
+  SUBSCRIPTIONS: 'subscriptions',
+  WEBHOOKS: 'webhooks',
+} as const;
+
+export const JOB_NAMES = {
+  // Email queue
+  SEND_EMAIL: 'send-email',
+
+  // Email marketing queue
+  SEND_CAMPAIGN: 'send-campaign',
+  PROCESS_CAMPAIGN: 'process-campaign',
+  RESUME_CAMPAIGN: 'resume-campaign',
+  SEND_AUTOMATION_EMAIL: 'send-automation-email',
+  CONTINUE_AUTOMATION: 'continue-automation',
+  CALL_WEBHOOK: 'call-webhook',
+
+  // Sync tasks queue
+  CONSISTENCY_CHECK: 'consistency-check',
+  REPLICATE_DATA: 'replicate-data',
+
+  // Backup processing queue
+  CREATE_BACKUP: 'create-backup',
+  VERIFY_BACKUP: 'verify-backup',
+  RECOVERY_TEST: 'recovery-test',
+  DELETE_BACKUP: 'delete-backup',
+
+  // Media processing queue
+  TRANSCODE_VIDEO: 'transcode-video',
+
+  // Payments queues
+  PROCESS_SUBSCRIPTION: 'process_subscription',
+  PROCESS_WEBHOOK: 'process-webhook',
+} as const;