Small ES6 library to lookup addresses by CEP. Supports multiple providers and automatically swaps providers on lookup failure.

cep_lookup.js

/**
 * kisuma-platform
 * cep_lookup.js
 *
 * Copyleft (c) LQDI Digital
 * www.lqdi.net - 2017
 * Licenced with MIT
 *
 * @author Aryel Tupinambá <[email protected]>
 */

import axios from "axios";

export default {

	providers: {
		'viacep': {
			uri: (cep) => ('http://viacep.com.br/ws/' + cep + '/json/'),
			mapper: (response) => {
				return {
					address: response.logradouro,
					neighborhood: response.bairro,
					city: response.localidade,
					uf: response.uf,
				}
			}
		},

		'postmon': {
			uri: (cep) => ('http://api.postmon.com.br/v1/cep/' + cep),
			mapper: (response) => {
				return {
					address: response.logradouro,
					neighborhood: response.bairro,
					city: response.cidade,
					uf: response.estado,
				}
			}
		}
	},

	priority: ['viacep', 'postmon'],

	lookup: function (cep, providerIndex = 0) {

		let provider = this.providers[this.priority[providerIndex]];

		return this.fetch(provider, cep, (res) => {
			if(providerIndex >= this.priority.length) throw res;
			return this.lookup(cep, ++providerIndex);
		})

	},

	fetch: function (provider, cep, onFailure) {
		return axios
			.get(provider.uri(cep))
			.then((response) => provider.mapper(response.data), onFailure);
	}

}