feature #3 - Add update exchange rate use case

src/1-domain/entities/exchangeRate.ts

@@ -0,0 +1,8 @@
+export interface ExchangeRate {
+  baseCurrency: string
+  rates: {
+    [currency: string]: number
+  }
+  createdAt?: Date
+  updatedAt?: Date
+}

src/1-domain/models/iExchangeRateResponse.ts

@@ -0,0 +1,9 @@
+export interface IExchangeRateResponse {
+  success: boolean
+  timestamp: number
+  base: string
+  date: string
+  rates: {
+    [currency: string]: number
+  }
+}

src/2-business/enums/currencyEnum.ts

@@ -0,0 +1,6 @@
+export enum CurrencyEnum {
+	BRL = 'BRL',
+	USD = 'USD',
+	EUR = 'EUR',
+	CAD = 'CAD'
+}

src/2-business/repositories/iExchangeRateRepository.ts

@@ -0,0 +1,5 @@
+import { ExchangeRate } from '../../1-domain/entities/exchangeRate'
+
+export interface IExchangeRateRepository {
+  create (entity: ExchangeRate): Promise<void>
+}

src/2-business/services/iExchangeRateService.ts

@@ -0,0 +1,6 @@
+import { IExchangeRateResponse } from '../../1-domain/models/iExchangeRateResponse'
+import { CurrencyEnum } from '../../2-business/enums/currencyEnum'
+
+export interface IExchangeRateService {
+  get (base: CurrencyEnum): Promise<IExchangeRateResponse>
+}

src/2-business/useCases/exchangeRate/updateExchangeRateUseCase.ts

@@ -0,0 +1,30 @@
+import { IExchangeRateRepository } from '../../repositories/iExchangeRateRepository'
+import { IExchangeRateService } from '../../services/iExchangeRateService'
+import { ExchangeRate } from '../../../1-domain/entities/exchangeRate'
+import { CurrencyEnum } from '../../enums/currencyEnum'
+import { IExchangeRateResponse } from '../../../1-domain/models/iExchangeRateResponse'
+
+export class UpdateExchangeRateUseCase {
+
+  constructor (
+		private exchangeRateRepository: IExchangeRateRepository,
+		private exchangeRateService: IExchangeRateService
+	) {}
+
+  private logPrefix: string = 'UpdateExchangeRateUseCase'
+
+  async execute (): Promise<void> {
+    console.log(`${this.logPrefix} :: start`)
+    try {
+      const exchangeRatesResponse: IExchangeRateResponse = await this.exchangeRateService.get(CurrencyEnum.BRL)
+      const exchangeRates: ExchangeRate = {
+        baseCurrency: exchangeRatesResponse.base,
+        rates: exchangeRatesResponse.rates
+      }
+      await this.exchangeRateRepository.create(exchangeRates)
+      console.log(`${this.logPrefix} :: end`)
+    } catch (error) {
+      throw error
+    }
+  }
+}

test/unit/2-business/updateExchangeRateUseCase.test.ts

@@ -0,0 +1,77 @@
+import { ExchangeRate } from '../../../src/1-domain/entities/exchangeRate'
+import { IExchangeRateResponse } from '../../../src/1-domain/models/iExchangeRateResponse'
+import { UpdateExchangeRateUseCase } from '../../../src/2-business/useCases/exchangeRate/updateExchangeRateUseCase'
+import { IExchangeRateRepository } from '../../../src/2-business/repositories/iExchangeRateRepository'
+import { IExchangeRateService } from '../../../src/2-business/services/iExchangeRateService'
+import { CurrencyEnum } from '../../../src/2-business/enums/currencyEnum'
+
+describe('UpdateExchangeRateUseCase', () => {
+  const exchangeRateMock: ExchangeRate = {
+    baseCurrency: 'BRL',
+    rates: {
+      'AUD': 1.566015,
+      'CAD': 1.560132,
+      'CHF': 1.154727,
+      'CNY': 7.827874,
+      'GBP': 0.882047,
+      'JPY': 132.360679,
+      'USD': 1.23396
+    }
+  }
+
+  const exchangeRateResponseMock: IExchangeRateResponse = {
+    success: true,
+    timestamp: 1519296206,
+    base: 'BRL',
+    date: '2021-03-17',
+    rates: {
+      AUD: 1.566015,
+      CAD: 1.560132,
+      CHF: 1.154727,
+      CNY: 7.827874,
+      GBP: 0.882047,
+      JPY: 132.360679,
+      USD: 1.23396
+    }
+  }
+
+  let exchangeRateRepository: IExchangeRateRepository
+  let exchangeRateService: IExchangeRateService
+
+  const setMocks = () => {
+    exchangeRateRepository = {
+      create: jest.fn().mockResolvedValue(null)
+    }
+    exchangeRateService = {
+      get: jest.fn().mockResolvedValue(exchangeRateResponseMock)
+    }
+  }
+
+  beforeEach(() => {
+    setMocks()
+  })
+
+  test('Success::should update the exchange rates successfully', async () => {
+    const useCase = new UpdateExchangeRateUseCase(
+			exchangeRateRepository,
+			exchangeRateService
+		)
+
+    await expect(useCase.execute()).resolves.not.toThrow()
+    expect(exchangeRateService.get).toHaveBeenCalledWith(CurrencyEnum.BRL)
+    expect(exchangeRateRepository.create).toHaveBeenCalledWith(exchangeRateMock)
+  })
+
+  test('Failure::should throw error when exchange rate service fails', async () => {
+    exchangeRateService = {
+      get: jest.fn().mockRejectedValue(new Error())
+    }
+
+    const useCase = new UpdateExchangeRateUseCase(
+			exchangeRateRepository,
+			exchangeRateService
+		)
+
+    await expect(useCase.execute()).rejects.toThrow()
+  })
+})