fix: prevent duplicate CPF registration and add findByCpf method

src/core/errors/use-case-error.ts

@@ -0,0 +1,3 @@
+export interface UseCaseError {
+  message: string
+}

src/domain/application/repositories/delivery-people.repository.ts

@@ -2,4 +2,5 @@ import { DeliveryPerson } from '@/domain/enterprise/entities/delivery-person'
 
 export abstract class DeliveryPeopleRepository {
   abstract create(deliveryPerson: DeliveryPerson): Promise<void>
+  abstract findByCpf(cpf: string): Promise<DeliveryPerson | null>
 }

src/domain/application/use-cases/errors/delivery-person-already-exists.error.ts

@@ -0,0 +1,10 @@
+import { UseCaseError } from '@/core/errors/use-case-error'
+
+export class DeliveryPersonAlreadyExistsError
+  extends Error
+  implements UseCaseError
+{
+  constructor() {
+    super('Delivery person already registered.')
+  }
+}

src/domain/application/use-cases/register-delivery-person.spec.ts

@@ -18,7 +18,8 @@ describe('Register Delivery Person', () => {
       password: '123456',
     })
 
-    expect(result.isRight).toBeTruthy()
+    expect(result.isRight()).toBeTruthy()
+    if (result.isLeft()) throw new Error()
     expect(result.value?.deliveryPerson.id).toBeTruthy()
     expect(result.value?.deliveryPerson.isAdmin()).toBeFalsy()
     expect(deliveryPersonRepository.items[0]).toEqual(

src/domain/application/use-cases/register-delivery-person.ts

@@ -1,7 +1,8 @@
-import { Either, right } from '@/core/either'
+import { Either, left, right } from '@/core/either'
 import { DeliveryPerson } from '@/domain/enterprise/entities/delivery-person'
 import { DeliveryPeopleRepository } from '../repositories/delivery-people.repository'
 import { Injectable } from '@nestjs/common'
+import { DeliveryPersonAlreadyExistsError } from './errors/delivery-person-already-exists.error'
 
 interface RegisterDeliveryPersonUseCaseRequest {
   name: string
@@ -11,7 +12,7 @@ interface RegisterDeliveryPersonUseCaseRequest {
 }
 
 type RegisterDeliveryPersonUseCaseResponse = Either<
-  null,
+  DeliveryPersonAlreadyExistsError,
   {
     deliveryPerson: DeliveryPerson
   }
@@ -34,6 +35,13 @@ export class RegisterDeliveryPersonUseCase {
       admin,
     })
 
+    const deliveryPersonOnDatabase =
+      await this.deliveryPeopleRepository.findByCpf(cpf)
+
+    if (deliveryPersonOnDatabase) {
+      return left(new DeliveryPersonAlreadyExistsError())
+    }
+
     await this.deliveryPeopleRepository.create(deliveryPerson)
 
     return right({ deliveryPerson })

src/infra/database/mongoose/repositories/mongoose-delivery-people.repository.ts

@@ -3,6 +3,7 @@ import { DeliveryPerson } from '@/domain/enterprise/entities/delivery-person'
 import { Injectable } from '@nestjs/common'
 import { MongooseDeliveryPersonMapper } from '../mappers/mongoose-delivery-person.mapper'
 import { MongooseService } from '../mongoose.service'
+import { UniqueEntityID } from '@/core/entities/unique-entity-id'
 
 @Injectable()
 export class MongooseDeliveryPeopleRepository
@@ -15,4 +16,20 @@ export class MongooseDeliveryPeopleRepository
 
     await this.mongoose.user.create(data)
   }
+
+  async findByCpf(cpf: string) {
+    const deliveryPerson = await this.mongoose.user.findOne({ cpf })
+
+    return deliveryPerson
+      ? DeliveryPerson.create(
+          {
+            name: deliveryPerson.name,
+            cpf: deliveryPerson.cpf,
+            admin: deliveryPerson.admin,
+            password: deliveryPerson.password,
+          },
+          new UniqueEntityID(deliveryPerson._id),
+        )
+      : null
+  }
 }

src/infra/http/controllers/create-user.controller.ts

@@ -1,8 +1,13 @@
 import { RegisterDeliveryPersonUseCase } from '@/domain/application/use-cases/register-delivery-person'
 import { ZodValidationPipe } from '@/infra/pipes/zod-validation.pipe'
-import { Body, Controller, Post, UsePipes } from '@nestjs/common'
+import {
+  Body,
+  ConflictException,
+  Controller,
+  Post,
+  UsePipes,
+} from '@nestjs/common'
 import { ApiBody, ApiOperation, ApiResponse, ApiTags } from '@nestjs/swagger'
-import { MongooseService } from 'src/infra/database/mongoose/mongoose.service'
 import { z } from 'zod'
 
 const registerBodySchema = z.object({
@@ -17,10 +22,7 @@ type RegisterBodySchema = z.infer<typeof registerBodySchema>
 @Controller('/users')
 @ApiTags('Users')
 export class CreateUserController {
-  constructor(
-    private mongoose: MongooseService,
-    private registerUseCase: RegisterDeliveryPersonUseCase,
-  ) {}
+  constructor(private registerUseCase: RegisterDeliveryPersonUseCase) {}
 
   @Post()
   @ApiOperation({ summary: 'Register a delivery person.' })
@@ -65,11 +67,17 @@ export class CreateUserController {
   @UsePipes(new ZodValidationPipe(registerBodySchema))
   async handle(@Body() body: RegisterBodySchema) {
     const { name, cpf, password, admin } = body
-    await this.registerUseCase.execute({
+
+    const result = await this.registerUseCase.execute({
       name,
       cpf,
       password,
       admin,
     })
+
+    if (result.isLeft()) {
+      const error = result.value
+      throw new ConflictException(error.message)
+    }
   }
 }

test/in-memory-repositories/delivery-people.repository.ts

@@ -9,4 +9,8 @@ export class InMemoryDeliveryPeopleRepository
   async create(deliveryPerson: DeliveryPerson): Promise<void> {
     this.items.push(deliveryPerson)
   }
+
+  async findByCpf(cpf: string): Promise<DeliveryPerson | null> {
+    return this.items.filter((item) => item.cpf === cpf)[0]
+  }
 }