NestJS集成Passport与JWT时出现Unknown authentication strategy "jwt"错误

错误信息 #

ERROR [ExceptionsHandler] Unknown authentication strategy "jwt"
Error: Unknown authentication strategy "jwt"
    at attempt (/path/to/node_modules/passport/lib/middleware/authenticate.js:193:39)
    at authenticate (/path/to/node_modules/passport/lib/middleware/authenticate.js:379:7)
    ...

问题背景 #

此前应用运行正常，近期未修改任何代码，但使用JWT令牌认证时突然出现上述错误，导致认证失败。

相关代码片段 #

Auth模块 #

import { Module } from '@nestjs/common';
import { AuthService } from './auth.service';
import { AuthController } from './auth.controller';
import { CommonModule } from '../common/common.module';
import { PassportModule } from '@nestjs/passport';
import { JwtModule } from '@nestjs/jwt';
import { ConfigModule, ConfigService } from '@nestjs/config';
import { JwtStrategy } from './strategies/jwt.strategy';
import { UsersService } from './users.service';
import { TypeOrmModule } from '@nestjs/typeorm';
import { User } from './entities/user.entity';

@Module({
  imports: [
    ConfigModule,
    CommonModule,
    PassportModule.register({ defaultStrategy: 'jwt' }),
    JwtModule.registerAsync({
      imports: [ConfigModule],
      inject: [ConfigService],
      useFactory: (configService: ConfigService) => ({
        secret: configService.get('SECRET_KEY'),
        signOptions: {
          expiresIn: '1d',
        },
      }),
    }),
    TypeOrmModule.forFeature([User]),
  ],
  controllers: [AuthController],
  providers: [AuthService, UsersService, JwtStrategy],
  exports: [PassportModule, JwtStrategy, JwtModule, AuthService],
})
export class AuthModule {}

JWT策略 #

import { Injectable } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';
import { PassportStrategy } from '@nestjs/passport';
import { ExtractJwt, Strategy } from 'passport-jwt';
import { CommonService } from '@/common/common.service';
import { ErrorCodes } from '@/common/interfaces/error-codes.interface';
import { User } from '../entities/user.entity';
import { JwtPayload } from '../interfaces/jwt-payload.interface';
import { UsersService } from '../users.service';

@Injectable()
export class JwtStrategy extends PassportStrategy(Strategy) {
  constructor(
    private readonly userService: UsersService,
    private readonly configService: ConfigService,
    private readonly commonService: CommonService,
  ) {
    super({
      secretOrKey: configService.get('SECRET_KEY'),
      jwtFromRequest: ExtractJwt.fromAuthHeaderAsBearerToken(),
      ignoreExpiration: false,
    });
  }

  async validate(payload: JwtPayload): Promise<User> {
    const { email } = payload;

    const user = await this.userService.findOneByEmail(email);

    if (!user) this.commonService.handleErrors(ErrorCodes.TokenNotValid);

    delete user.password, user.name, user.email;

    return user;
  }
}

当前依赖版本 #

"@nestjs/passport": "10.0.3"
"@nestjs/jwt": "^10.2.0"
"passport": "^0.7.0"
"passport-jwt": "^4.0.1"

已尝试的解决步骤 #

• 执行npm install重装所有依赖
• 确认环境变量SECRET_KEY配置正确
• 校验@nestjs/passport、@nestjs/jwt和passport-jwt版本兼容性

排查与解决方案 #

1. 检查模块导入完整性 #

确保使用@UseGuards(AuthGuard('jwt'))的模块已正确导入AuthModule，或直接导入PassportModule与JwtStrategy。模块间依赖缺失会导致Passport无法识别jwt策略。

2. 验证JwtStrategy的注册与注入 #

• 确认JwtStrategy类上的@Injectable()装饰器未被误删
• 检查AuthModule的providers数组是否包含JwtStrategy，且导出配置正确（若其他模块需使用）

3. 清理缓存与重新构建 #

• 删除node_modules和package-lock.json，重新执行npm install
• 删除dist编译目录，执行npm run build重新编译项目

4. 检查Passport初始化顺序 #

确保PassportModule在JwtModule之前导入，避免策略注册延迟。可尝试在PassportModule.register时显式指定策略名称，确保与AuthGuard中使用的名称一致。

5. 验证环境变量加载时机 #

在JwtStrategy构造函数中打印configService.get('SECRET_KEY')，确认变量已正确加载。若ConfigModule未全局注册，需确保JwtStrategy所在模块已导入ConfigModule。

6. 锁定依赖版本到历史正常版本 #

若版本兼容问题导致策略注册失败，可尝试锁定到之前运行正常的依赖版本，例如：

"@nestjs/passport": "10.0.3",
"@nestjs/jwt": "10.1.1",
"passport": "0.6.0",
"passport-jwt": "4.0.1"

内容的提问来源于stack exchange，提问作者JDorozco