feat: add authorization

src/app.controller.spec.ts

@@ -1,59 +0,0 @@
-import { Test, TestingModule } from '@nestjs/testing';
-import { INestApplication } from '@nestjs/common';
-import { DocumentBuilder, OpenAPIObject, SwaggerModule } from '@nestjs/swagger';
-import { AppController } from './app.controller';
-import { AppService } from './app.service';
-
-describe('AppController', () => {
-  let appController: AppController;
-
-  beforeEach(async () => {
-    const app: TestingModule = await Test.createTestingModule({
-      controllers: [AppController],
-      providers: [AppService],
-    }).compile();
-
-    appController = app.get<AppController>(AppController);
-  });
-
-  it('documents the safe internal error response', async () => {
-    const module: TestingModule = await Test.createTestingModule({
-      controllers: [AppController],
-      providers: [AppService],
-    }).compile();
-    const app: INestApplication = module.createNestApplication();
-    app.setGlobalPrefix('api/v1');
-
-    const document: OpenAPIObject = SwaggerModule.createDocument(
-      app,
-      new DocumentBuilder().build(),
-    );
-
-    expect(document.paths['/api/v1']?.get?.responses['500']).toEqual({
-      description: 'Internal server error',
-      content: {
-        'application/json': {
-          schema: { $ref: '#/components/schemas/SafeErrorResponseDto' },
-        },
-      },
-    });
-
-    expect(document.paths['/api/v1']?.get?.responses['200']).toEqual(
-      expect.objectContaining({
-        content: {
-          'application/json': {
-            schema: { type: 'string', example: 'Hello World!' },
-          },
-        },
-      }),
-    );
-
-    await app.close();
-  });
-
-  describe('root', () => {
-    it('should return "Hello World!"', () => {
-      expect(appController.getHello()).toBe('Hello World!');
-    });
-  });
-});

src/app.controller.ts

@@ -1,18 +0,0 @@
-import { Controller, Get } from '@nestjs/common';
-import { ApiOkResponse } from '@nestjs/swagger';
-import { ApiSafeErrorResponse } from './common/decorators/api-safe-error-response.decorator';
-import { AppService } from './app.service';
-
-@Controller()
-export class AppController {
-  constructor(private readonly appService: AppService) {}
-
-  @Get()
-  @ApiOkResponse({
-    schema: { type: 'string', example: 'Hello World!' },
-  })
-  @ApiSafeErrorResponse()
-  getHello(): string {
-    return this.appService.getHello();
-  }
-}

src/app.module.ts

@@ -1,7 +1,6 @@
 import { Module } from '@nestjs/common';
 import { ConfigModule } from '@nestjs/config';
-import { AppController } from './app.controller';
-import { AppService } from './app.service';
+import { AuthModule } from './auth/auth.module';
 import { validateEnv } from './config/env.validation';
 import { PrismaModule } from './prisma/prisma.module';
 
@@ -12,8 +11,7 @@ import { PrismaModule } from './prisma/prisma.module';
       validate: validateEnv,
     }),
     PrismaModule,
+    AuthModule,
   ],
-  controllers: [AppController],
-  providers: [AppService],
 })
 export class AppModule {}

src/app.service.ts

@@ -1,8 +0,0 @@
-import { Injectable } from '@nestjs/common';
-
-@Injectable()
-export class AppService {
-  getHello(): string {
-    return 'Hello World!';
-  }
-}

src/auth/auth.controller.ts

@@ -0,0 +1,138 @@
+import {
+  Body,
+  Controller,
+  Get,
+  HttpCode,
+  Post,
+  Req,
+  Res,
+  UseGuards,
+  UnauthorizedException,
+} from '@nestjs/common';
+import {
+  ApiBearerAuth,
+  ApiNoContentResponse,
+  ApiOkResponse,
+  ApiProperty,
+  ApiTags,
+} from '@nestjs/swagger';
+import type { Request, Response } from 'express';
+import { CredentialsDto } from './auth.dto';
+import { AuthService } from './auth.service';
+import { AccessPayload } from './auth.types';
+import { JwtAuthGuard } from './jwt-auth.guard';
+
+const REFRESH_COOKIE = 'refresh_token';
+const COOKIE_PATH = '/api/v1/auth';
+
+class UserDto {
+  @ApiProperty()
+  id: string;
+
+  @ApiProperty()
+  email: string;
+}
+
+class AuthenticationDto {
+  @ApiProperty()
+  accessToken: string;
+
+  @ApiProperty({ type: UserDto })
+  user: UserDto;
+}
+
+@ApiTags('auth')
+@Controller('auth')
+export class AuthController {
+  constructor(private readonly auth: AuthService) {}
+
+  @Post('register')
+  @ApiOkResponse({ type: AuthenticationDto })
+  async register(
+    @Body() credentials: CredentialsDto,
+    @Res({ passthrough: true }) response: Response,
+  ) {
+    return this.respond(
+      response,
+      await this.auth.register(credentials.email, credentials.password),
+    );
+  }
+
+  @Post('login')
+  @ApiOkResponse({ type: AuthenticationDto })
+  async login(
+    @Body() credentials: CredentialsDto,
+    @Res({ passthrough: true }) response: Response,
+  ) {
+    return this.respond(
+      response,
+      await this.auth.login(credentials.email, credentials.password),
+    );
+  }
+
+  @Post('refresh')
+  @ApiOkResponse({ type: AuthenticationDto })
+  async refresh(
+    @Req() request: Request,
+    @Res({ passthrough: true }) response: Response,
+  ) {
+    try {
+      const token = this.refreshToken(request);
+      if (!token) throw new UnauthorizedException({ code: 'UNAUTHORIZED' });
+      return this.respond(response, await this.auth.refresh(token));
+    } catch (error) {
+      this.clearCookie(response);
+      throw error;
+    }
+  }
+
+  @Post('logout')
+  @HttpCode(204)
+  @ApiNoContentResponse()
+  async logout(
+    @Req() request: Request,
+    @Res({ passthrough: true }) response: Response,
+  ): Promise<void> {
+    await this.auth.logout(this.refreshToken(request));
+    this.clearCookie(response);
+  }
+
+  @Get('me')
+  @UseGuards(JwtAuthGuard)
+  @ApiBearerAuth()
+  @ApiOkResponse({ type: UserDto })
+  async me(@Req() request: Request & { user: AccessPayload }) {
+    const user = await this.auth.userById(request.user.sub);
+    return this.auth.toUser(user);
+  }
+
+  private respond(
+    response: Response,
+    result: {
+      user: { id: string; email: string };
+      accessToken: string;
+      refreshToken: string;
+    },
+  ) {
+    response.cookie(REFRESH_COOKIE, result.refreshToken, this.cookieOptions());
+    return { user: result.user, accessToken: result.accessToken };
+  }
+
+  private clearCookie(response: Response): void {
+    response.clearCookie(REFRESH_COOKIE, this.cookieOptions());
+  }
+
+  private refreshToken(request: Request): string | undefined {
+    const token: unknown = request.cookies?.[REFRESH_COOKIE];
+    return typeof token === 'string' ? token : undefined;
+  }
+
+  private cookieOptions() {
+    return {
+      httpOnly: true,
+      sameSite: 'lax' as const,
+      secure: process.env['NODE_ENV'] !== 'development',
+      path: COOKIE_PATH,
+    };
+  }
+}

src/auth/auth.dto.ts

@@ -0,0 +1,57 @@
+import {
+  IsString,
+  MinLength,
+  Validate,
+  ValidatorConstraint,
+} from 'class-validator';
+import { Transform } from 'class-transformer';
+import { ApiProperty } from '@nestjs/swagger';
+
+@ValidatorConstraint({ name: 'email' })
+class EmailConstraint {
+  validate(value: unknown): boolean {
+    return (
+      typeof value === 'string' &&
+      value.length <= 254 &&
+      value.split('@').length === 2 &&
+      !value
+        .split('')
+        .some(
+          (character) =>
+            /\s/.test(character) ||
+            character.charCodeAt(0) < 32 ||
+            character.charCodeAt(0) === 127,
+        ) &&
+      value.split('@').every(Boolean)
+    );
+  }
+  defaultMessage(): string {
+    return 'must be a valid email address';
+  }
+}
+
+@ValidatorConstraint({ name: 'passwordBytes' })
+class PasswordBytesConstraint {
+  validate(value: unknown): boolean {
+    return typeof value === 'string' && Buffer.byteLength(value, 'utf8') <= 72;
+  }
+  defaultMessage(): string {
+    return 'must not exceed 72 UTF-8 bytes';
+  }
+}
+
+export class CredentialsDto {
+  @ApiProperty({ example: 'user@example.com' })
+  @IsString()
+  @Transform(({ value }: { value: unknown }) =>
+    typeof value === 'string' ? value.trim().toLowerCase() : value,
+  )
+  @Validate(EmailConstraint)
+  email: string;
+
+  @ApiProperty({ minLength: 12, maxLength: 72, example: 'a secure password' })
+  @IsString()
+  @MinLength(12)
+  @Validate(PasswordBytesConstraint)
+  password: string;
+}

src/auth/auth.module.ts

@@ -0,0 +1,25 @@
+import { Module } from '@nestjs/common';
+import { ConfigModule, ConfigService } from '@nestjs/config';
+import { JwtModule } from '@nestjs/jwt';
+import { PassportModule } from '@nestjs/passport';
+import { Environment } from '../config/env.validation';
+import { AuthController } from './auth.controller';
+import { AuthService } from './auth.service';
+import { JwtAuthGuard } from './jwt-auth.guard';
+import { JwtStrategy } from './jwt.strategy';
+
+@Module({
+  imports: [
+    PassportModule,
+    JwtModule.registerAsync({
+      imports: [ConfigModule],
+      inject: [ConfigService],
+      useFactory: (config: ConfigService<Environment, true>) => ({
+        secret: config.getOrThrow('JWT_SECRET'),
+      }),
+    }),
+  ],
+  controllers: [AuthController],
+  providers: [AuthService, JwtStrategy, JwtAuthGuard],
+})
+export class AuthModule {}

src/auth/auth.service.ts

@@ -0,0 +1,184 @@
+import {
+  ConflictException,
+  Injectable,
+  UnauthorizedException,
+} from '@nestjs/common';
+import { JwtService } from '@nestjs/jwt';
+import * as bcrypt from 'bcrypt';
+import { createHash, randomUUID } from 'crypto';
+import { Session, User } from '../../generated/prisma/client';
+import { PrismaService } from '../prisma/prisma.service';
+import { AuthUser, RefreshPayload } from './auth.types';
+
+const ACCESS_TTL = '15m';
+const REFRESH_TTL = '7d';
+const DUMMY_PASSWORD_HASH =
+  '$2b$12$Z49BwJsyiUqY0ZozFzt9IeYvjhV4kbeLw9KdxOguT5bfhA1RvPCx6';
+
+@Injectable()
+export class AuthService {
+  constructor(
+    private readonly prisma: PrismaService,
+    private readonly jwt: JwtService,
+  ) {}
+
+  async register(
+    email: string,
+    password: string,
+  ): Promise<{ user: AuthUser; accessToken: string; refreshToken: string }> {
+    const normalizedEmail = this.normalizeEmail(email);
+    const existing = await this.prisma.user.findUnique({
+      where: { email: normalizedEmail },
+    });
+    if (existing)
+      throw new ConflictException({ code: 'EMAIL_ALREADY_REGISTERED' });
+
+    const user = await this.prisma.user.create({
+      data: {
+        id: randomUUID(),
+        email: normalizedEmail,
+        passwordHash: await bcrypt.hash(password, 12),
+      },
+    });
+    return this.createSession(user);
+  }
+
+  async login(
+    email: string,
+    password: string,
+  ): Promise<{ user: AuthUser; accessToken: string; refreshToken: string }> {
+    const user = await this.prisma.user.findUnique({
+      where: { email: this.normalizeEmail(email) },
+    });
+    const valid = await bcrypt.compare(
+      password,
+      user?.passwordHash ?? DUMMY_PASSWORD_HASH,
+    );
+    if (!user || !valid)
+      throw new UnauthorizedException({ code: 'INVALID_CREDENTIALS' });
+    return this.createSession(user);
+  }
+
+  async refresh(
+    token: string,
+  ): Promise<{ user: AuthUser; accessToken: string; refreshToken: string }> {
+    let payload: RefreshPayload;
+    try {
+      payload = await this.jwt.verifyAsync<RefreshPayload>(token, {
+        algorithms: ['HS256'],
+      });
+    } catch {
+      throw new UnauthorizedException({ code: 'UNAUTHORIZED' });
+    }
+    if (payload.type !== 'refresh')
+      throw new UnauthorizedException({ code: 'UNAUTHORIZED' });
+    const session = await this.prisma.session.findUnique({
+      where: { id: payload.sid },
+      include: { user: true },
+    });
+    if (
+      !session ||
+      session.userId !== payload.sub ||
+      session.revokedAt ||
+      session.expiresAt <= new Date()
+    ) {
+      if (session && !session.revokedAt)
+        await this.prisma.session.delete({ where: { id: session.id } });
+      throw new UnauthorizedException({ code: 'UNAUTHORIZED' });
+    }
+    if (session.refreshTokenHash !== this.hash(token)) {
+      await this.prisma.session.update({
+        where: { id: session.id },
+        data: { revokedAt: new Date() },
+      });
+      throw new UnauthorizedException({ code: 'UNAUTHORIZED' });
+    }
+    return this.rotateSession(session);
+  }
+
+  async logout(token?: string): Promise<void> {
+    if (!token) return;
+    try {
+      const payload = await this.jwt.verifyAsync<RefreshPayload>(token, {
+        algorithms: ['HS256'],
+      });
+      if (payload.type !== 'refresh') return;
+      const session = await this.prisma.session.findUnique({
+        where: { id: payload.sid },
+      });
+      if (
+        session &&
+        !session.revokedAt &&
+        session.refreshTokenHash === this.hash(token)
+      ) {
+        await this.prisma.session.update({
+          where: { id: session.id },
+          data: { revokedAt: new Date() },
+        });
+      }
+    } catch {
+      // Logout is intentionally idempotent.
+    }
+  }
+
+  toUser(user: User): AuthUser {
+    return { id: user.id, email: user.email };
+  }
+
+  async userById(id: string): Promise<User> {
+    const user = await this.prisma.user.findUnique({ where: { id } });
+    if (!user) throw new UnauthorizedException({ code: 'UNAUTHORIZED' });
+    return user;
+  }
+
+  private async createSession(
+    user: User,
+  ): Promise<{ user: AuthUser; accessToken: string; refreshToken: string }> {
+    const session = await this.prisma.session.create({
+      data: {
+        id: randomUUID(),
+        userId: user.id,
+        refreshTokenHash: '',
+        expiresAt: new Date(),
+      },
+    });
+    return this.rotateSession({ ...session, user });
+  }
+
+  private async rotateSession(
+    session: Session & { user: User },
+  ): Promise<{ user: AuthUser; accessToken: string; refreshToken: string }> {
+    const refreshToken = await this.jwt.signAsync(
+      {
+        sub: session.userId,
+        sid: session.id,
+        type: 'refresh',
+        jti: randomUUID(),
+      },
+      { expiresIn: REFRESH_TTL, algorithm: 'HS256' },
+    );
+    await this.prisma.session.update({
+      where: { id: session.id },
+      data: {
+        refreshTokenHash: this.hash(refreshToken),
+        expiresAt: new Date(Date.now() + 7 * 24 * 60 * 60 * 1000),
+      },
+    });
+    return {
+      user: this.toUser(session.user),
+      accessToken: await this.jwt.signAsync(
+        { sub: session.userId, sid: session.id, type: 'access' },
+        { expiresIn: ACCESS_TTL, algorithm: 'HS256' },
+      ),
+      refreshToken,
+    };
+  }
+
+  private normalizeEmail(email: string): string {
+    return email;
+  }
+
+  private hash(token: string): string {
+    return createHash('sha256').update(token).digest('hex');
+  }
+}

src/auth/auth.types.ts

@@ -0,0 +1,17 @@
+export interface AuthUser {
+  id: string;
+  email: string;
+}
+
+export interface AccessPayload {
+  sub: string;
+  sid: string;
+  type: 'access';
+}
+
+export interface RefreshPayload {
+  sub: string;
+  sid: string;
+  type: 'refresh';
+  jti: string;
+}

src/auth/jwt-auth.guard.ts

@@ -0,0 +1,5 @@
+import { Injectable } from '@nestjs/common';
+import { AuthGuard } from '@nestjs/passport';
+
+@Injectable()
+export class JwtAuthGuard extends AuthGuard('jwt') {}

src/auth/jwt.strategy.ts

@@ -0,0 +1,24 @@
+import { Injectable, UnauthorizedException } from '@nestjs/common';
+import { ConfigService } from '@nestjs/config';
+import { PassportStrategy } from '@nestjs/passport';
+import { ExtractJwt, Strategy } from 'passport-jwt';
+import { Environment } from '../config/env.validation';
+import { AccessPayload } from './auth.types';
+
+@Injectable()
+export class JwtStrategy extends PassportStrategy(Strategy) {
+  constructor(config: ConfigService<Environment, true>) {
+    super({
+      jwtFromRequest: ExtractJwt.fromAuthHeaderAsBearerToken(),
+      ignoreExpiration: false,
+      secretOrKey: config.getOrThrow('JWT_SECRET'),
+      algorithms: ['HS256'],
+    });
+  }
+
+  validate(payload: AccessPayload): AccessPayload {
+    if (payload.type !== 'access')
+      throw new UnauthorizedException({ code: 'UNAUTHORIZED' });
+    return payload;
+  }
+}

src/common/filters/http-exception.filter.spec.ts

@@ -4,25 +4,22 @@ import { HttpExceptionFilter } from './http-exception.filter';
 describe('HttpExceptionFilter', () => {
   it('does not expose internal error details', () => {
     const status = jest.fn().mockReturnThis();
+    const type = jest.fn().mockReturnThis();
     const json = jest.fn();
     const filter = new HttpExceptionFilter();
     const host = {
       switchToHttp: () => ({
-        getRequest: () => ({
-          path: '/api/v1/health',
-          url: '/api/v1/health?access_token=secret',
-        }),
-        getResponse: () => ({ status, json }),
+        getResponse: () => ({ status, type, json }),
       }),
     } as unknown as ArgumentsHost;
 
     filter.catch(new Error('database password: secret'), host);
 
     expect(status).toHaveBeenCalledWith(500);
+    expect(type).toHaveBeenCalledWith('application/problem+json');
     expect(json).toHaveBeenCalledWith({
-      statusCode: 500,
-      message: 'Internal server error',
-      path: '/api/v1/health',
+      status: 500,
+      code: 'INTERNAL_SERVER_ERROR',
     });
   });
 });

src/common/filters/http-exception.filter.ts

@@ -4,24 +4,65 @@ import {
   ExceptionFilter,
   HttpException,
   HttpStatus,
+  ValidationError,
 } from '@nestjs/common';
-import { Request, Response } from 'express';
+import type { Response } from 'express';
 
 @Catch()
 export class HttpExceptionFilter implements ExceptionFilter {
   catch(exception: unknown, host: ArgumentsHost): void {
     const context = host.switchToHttp();
     const response = context.getResponse<Response>();
-    const request = context.getRequest<Request>();
     const status =
       exception instanceof HttpException
         ? exception.getStatus()
         : HttpStatus.INTERNAL_SERVER_ERROR;
 
-    response.status(status).json({
-      statusCode: status,
-      message: status === 500 ? 'Internal server error' : 'Request failed',
-      path: request.path,
-    });
+    const payload =
+      exception instanceof HttpException ? exception.getResponse() : undefined;
+    const isValidation = Array.isArray(
+      (payload as { message?: unknown })?.message,
+    );
+    response
+      .status(status)
+      .type('application/problem+json')
+      .json({
+        status,
+        code: isValidation ? 'VALIDATION_ERROR' : this.codeFor(status, payload),
+        ...(isValidation
+          ? {
+              errors: this.validationErrors(
+                (payload as { message: ValidationError[] }).message,
+              ),
+            }
+          : {}),
+      });
+  }
+
+  private codeFor(status: number, payload: unknown): string {
+    if (typeof payload === 'object' && payload !== null && 'code' in payload) {
+      const code = (payload as { code?: unknown }).code;
+      if (typeof code === 'string') return code;
+    }
+    return (
+      {
+        400: 'BAD_REQUEST',
+        401: 'UNAUTHORIZED',
+        404: 'NOT_FOUND',
+        415: 'UNSUPPORTED_MEDIA_TYPE',
+        500: 'INTERNAL_SERVER_ERROR',
+      }[status] ?? 'INTERNAL_SERVER_ERROR'
+    );
+  }
+
+  private validationErrors(
+    errors: ValidationError[],
+  ): { pointer: string; detail: string }[] {
+    return errors.flatMap((error) =>
+      Object.values(error.constraints ?? {}).map((detail) => ({
+        pointer: `#/${error.property}`,
+        detail,
+      })),
+    );
   }
 }

src/config/env.validation.spec.ts

@@ -6,11 +6,13 @@ describe('validateEnv', () => {
       validateEnv({
         DATABASE_URL: 'file:./data.db',
         FRONTEND_ORIGIN: 'http://localhost:5173/',
+        JWT_SECRET: 'a-secret-that-is-at-least-thirty-two-characters',
       }),
     ).toEqual({
       DATABASE_URL: 'file:./data.db',
       FRONTEND_ORIGIN: 'http://localhost:5173',
       PORT: 3000,
+      JWT_SECRET: 'a-secret-that-is-at-least-thirty-two-characters',
     });
   });
 
@@ -32,6 +34,7 @@ describe('validateEnv', () => {
         validateEnv({
           DATABASE_URL: 'file:./data.db',
           FRONTEND_ORIGIN: origin,
+          JWT_SECRET: 'a-secret-that-is-at-least-thirty-two-characters',
         }),
       ).toThrow('FRONTEND_ORIGIN must be a valid HTTP origin');
     },

src/config/env.validation.ts

@@ -1,6 +1,7 @@
 export interface Environment {
   DATABASE_URL: string;
   FRONTEND_ORIGIN: string;
+  JWT_SECRET: string;
   PORT: number;
 }
 
@@ -8,6 +9,7 @@ export function validateEnv(config: Record<string, unknown>): Environment {
   const databaseUrl = config['DATABASE_URL'];
   const frontendOrigin = config['FRONTEND_ORIGIN'];
   const port = config['PORT'] ?? 3000;
+  const jwtSecret = config['JWT_SECRET'];
 
   if (typeof databaseUrl !== 'string' || !databaseUrl.startsWith('file:')) {
     throw new Error('DATABASE_URL must be a SQLite file URL');
@@ -38,9 +40,14 @@ export function validateEnv(config: Record<string, unknown>): Environment {
     throw new Error('PORT must be a valid port number');
   }
 
+  if (typeof jwtSecret !== 'string' || jwtSecret.length < 32) {
+    throw new Error('JWT_SECRET must be at least 32 characters long');
+  }
+
   return {
     DATABASE_URL: databaseUrl,
     FRONTEND_ORIGIN: parsedOrigin.origin,
+    JWT_SECRET: jwtSecret,
     PORT: parsedPort,
   };
 }

src/main.ts

@@ -1,4 +1,6 @@
+import { ValidationPipe } from '@nestjs/common';
 import { NestFactory } from '@nestjs/core';
+import cookieParser from 'cookie-parser';
 import { ConfigService } from '@nestjs/config';
 import { DocumentBuilder, SwaggerModule } from '@nestjs/swagger';
 import { AppModule } from './app.module';
@@ -11,8 +13,10 @@ async function bootstrap() {
   const config = app.get<ConfigService<Environment, true>>(ConfigService);
   const frontendOrigin = config.getOrThrow<string>('FRONTEND_ORIGIN');
 
-  app.enableCors({ origin: frontendOrigin });
+  app.enableCors({ origin: frontendOrigin, credentials: true });
   app.setGlobalPrefix('api/v1');
+  app.use(cookieParser());
+  app.useGlobalPipes(new ValidationPipe({ transform: true, whitelist: true }));
   app.useGlobalFilters(new HttpExceptionFilter());
 
   if (shouldExposeSwagger(process.env['NODE_ENV'])) {