setup auth module

src/app.module.ts

@@ -1,6 +1,7 @@
 import { Module } from '@nestjs/common';
 import { TasksModule } from './tasks/tasks.module';
 import { TypeOrmModule } from '@nestjs/typeorm';
+import { AuthModule } from './auth/auth.module';
 @Module({
   imports: [
     TasksModule,
@@ -14,6 +15,7 @@ import { TypeOrmModule } from '@nestjs/typeorm';
       autoLoadEntities: true,
       synchronize: true,
     }),
+    AuthModule,
   ],
 })
 export class AppModule {}

src/auth/auth.controller.ts

@@ -0,0 +1,13 @@
+import { Body, Controller, Post } from '@nestjs/common';
+import { AuthService } from 'src/auth/auth.service';
+import { AuthCredentialDto } from 'src/auth/dto/auth-credentials.dto';
+
+@Controller('auth')
+export class AuthController {
+  constructor(private authService: AuthService) {}
+
+  @Post('/signup')
+  signup(@Body() authCredentialDto: AuthCredentialDto): Promise<void> {
+    return this.authService.signup(authCredentialDto);
+  }
+}

src/auth/auth.module.ts

@@ -0,0 +1,12 @@
+import { Module } from '@nestjs/common';
+import { TypeOrmModule } from '@nestjs/typeorm';
+import { UsersRepository } from 'src/auth/users.repository';
+import { AuthController } from './auth.controller';
+import { AuthService } from './auth.service';
+
+@Module({
+  imports: [TypeOrmModule.forFeature([UsersRepository])],
+  controllers: [AuthController],
+  providers: [AuthService],
+})
+export class AuthModule {}

src/auth/auth.service.ts

@@ -0,0 +1,16 @@
+import { Injectable } from '@nestjs/common';
+import { InjectRepository } from '@nestjs/typeorm';
+import { AuthCredentialDto } from 'src/auth/dto/auth-credentials.dto';
+import { UsersRepository } from 'src/auth/users.repository';
+
+@Injectable()
+export class AuthService {
+  constructor(
+    @InjectRepository(UsersRepository)
+    private usersRepository: UsersRepository,
+  ) {}
+
+  async signup(authCredentialDto: AuthCredentialDto): Promise<void> {
+    return await this.usersRepository.createUser(authCredentialDto);
+  }
+}

src/auth/dto/auth-credentials.dto.ts

@@ -0,0 +1,16 @@
+import { IsString, Matches, MaxLength, MinLength } from 'class-validator';
+
+export class AuthCredentialDto {
+  @IsString()
+  @MinLength(4)
+  @MaxLength(20)
+  username: string;
+
+  @IsString()
+  @MinLength(8)
+  @MaxLength(32)
+  @Matches(/((?=.*\d)|(?=.*\W+))(?![.\n])(?=.*[A-Z])(?=.*[a-z]).*$/, {
+    message: 'password is too weak',
+  })
+  password: string;
+}

src/auth/user.entity.ts

@@ -0,0 +1,13 @@
+import { Entity, PrimaryGeneratedColumn, Column } from 'typeorm';
+
+@Entity()
+export class User {
+  @PrimaryGeneratedColumn('uuid')
+  id: string;
+
+  @Column({ unique: true })
+  username: string;
+
+  @Column()
+  password: string;
+}

src/auth/users.repository.ts

@@ -0,0 +1,25 @@
+import {
+  ConflictException,
+  InternalServerErrorException,
+} from '@nestjs/common';
+import { AuthCredentialDto } from 'src/auth/dto/auth-credentials.dto';
+import { User } from 'src/auth/user.entity';
+import { EntityRepository, Repository } from 'typeorm';
+
+@EntityRepository(User)
+export class UsersRepository extends Repository<User> {
+  async createUser(authCredentialDto: AuthCredentialDto): Promise<void> {
+    const { username, password } = authCredentialDto;
+    const user = this.create({ username, password });
+    try {
+      await this.save(user);
+    } catch (error) {
+      if (Number(error.code) === 23505) {
+        //duplicate username
+        throw new ConflictException('username already exists');
+      } else {
+        throw new InternalServerErrorException();
+      }
+    }
+  }
+}