add Correios Alt service provider

Author: mshlz

src/services/correios-alt.js

@@ -0,0 +1,58 @@
+'use strict'
+
+import fetch from 'node-fetch'
+import ServiceError from '../errors/service.js'
+
+export default function fetchCorreiosAltAPIService(
+  cepWithLeftPad,
+  proxyURL = ''
+) {
+  const url = `${proxyURL}https://buscacepinter.correios.com.br/app/cep/carrega-cep.php?cep=${cepWithLeftPad}`
+  const options = {
+    method: 'GET',
+    mode: 'cors',
+    headers: {
+      'content-type': 'application/json;charset=utf-8'
+    }
+  }
+
+  return fetch(url, options)
+    .then(parseResponse)
+    .then(extractCepValuesFromResponse)
+    .catch(throwApplicationError)
+}
+
+async function parseResponse(response) {
+  response = await response.json()
+
+  if (response.erro === true || response.total === 0) {
+    throw new Error('CEP não encontrado na base dos Correios.')
+  }
+
+  return response
+}
+
+function extractCepValuesFromResponse(response) {
+  const firstCep = response.dados[0]
+  return {
+    cep: firstCep.cep,
+    state: firstCep.uf,
+    city: firstCep.localidade,
+    neighborhood: firstCep.bairro,
+    street: firstCep.logradouroDNEC,
+    service: 'correios'
+  }
+}
+
+function throwApplicationError(error) {
+  const serviceError = new ServiceError({
+    message: error.message,
+    service: 'correios'
+  })
+
+  if (error.name === 'FetchError') {
+    serviceError.message = 'Erro ao se conectar com o serviço dos Correios.'
+  }
+
+  throw serviceError
+}

src/services/index.js

@@ -1,4 +1,5 @@
 import Correios from './correios'
+import CorreiosAlt from './correios-alt'
 import ViaCep from './viacep'
 import WideNet from './widenet'
 import BrasilAPI from './brasilapi.js'
@@ -16,6 +17,7 @@ export function getAvailableServices () {
 
   return {
     correios: Correios,
+    'correios-alt': CorreiosAlt,
     viacep: ViaCep,
     widenet: WideNet,
     brasilapi: BrasilAPI