se agrego el metodo downloadFile

lib/request.js

@@ -1,4 +1,13 @@
-import {isString, URLMaker, parsePathParams} from './utils/helpers.js';
+import RNFS from 'react-native-fs';
+import {
+	isString,
+	URLMaker,
+	parsePathParams,
+	promiseWrapper,
+	isObject,
+	isFunction,
+	isNumber,
+} from './utils/helpers.js';
 import crashlytics from './utils/crashlytics.js';
 import updateHeaders from './utils/updateHeaders.js';
 import parseQueryParams from './utils/parseQueryParams.js';
@@ -381,6 +390,91 @@ class Request {
 			return Promise.reject(formattedError);
 		}
 	}
+
+	/**
+	* @name downloadFile
+	* @description Download a file and save it in the phone using react-native-fs package
+	* @param {string} fileName - File name for the document with its extension | .zip .pdf etc
+	* @param {string} folderPath - The path for folder where the document is stored
+	* @param {string} url - url where file is stored
+	* @param {object} headers - An object of headers to be passed to the server
+	* @param {function} begin - callback it is invoked once at the beginning of the process with the response headers and download data
+	* @param {function} progress - callback that receives the download trace
+	* @param {number} progressInterval - it will return progress events in the maximum frequency of progressInterval
+	* @param {number} progressDivider - it will return progress events that divided by progressDivider
+	* @returns {Promise} Response from package | {jobId: number, statusCode: number, bytesWritten: number}
+	* @example
+	* const request = new Request({JANIS_ENV: 'janis_dev'})
+	* const pdfFile = await request.downloadFile({
+					url: `https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf`,
+					fileName: `dummy.pdf`,
+					folderPath: `${RNFS.DocumentDirectoryPath}/pdfs`,
+					progress: ({jobId, contentLength, bytesWritten }) => {},
+					progressDivider: 10
+				})
+   */
+	async downloadFile({
+		fileName,
+		folderPath,
+		url,
+		headers,
+		begin,
+		progress,
+		progressInterval,
+		progressDivider,
+		...props
+	}) {
+		try {
+			if (!fileName || !isString(fileName)) throw new Error('fileName is not valid');
+			if (!folderPath || !isString(folderPath)) throw new Error('folderPath is not valid');
+			if (!url || !isString(url)) throw new Error('url is not valid');
+
+			const validHeaders = headers && isObject(headers);
+			const validBegin = begin && isFunction(begin);
+			const validProgress = progress && isFunction(progress);
+			const validProgressInterval = progressInterval && isNumber(progressInterval);
+			const validProgressDivider = progressDivider && isNumber(progressDivider);
+
+			const [downloadRes, downloadErr] = await promiseWrapper(
+				RNFS.downloadFile({
+					fromUrl: url,
+					toFile: `${folderPath}/${fileName}`,
+					...(validHeaders && {headers}),
+					...(validBegin && {begin}),
+					...(validProgress && {progress}),
+					...(validProgressInterval && {progressInterval}),
+					...(validProgressDivider && {progressDivider}),
+					...{...props},
+				}).promise,
+			);
+
+			if (downloadErr) throw new Error(downloadErr.message);
+			if (
+				!isObject(downloadRes) ||
+				!downloadRes ||
+				downloadRes.bytesWritten === 0 ||
+				downloadRes.statusCode !== 200
+			)
+				throw new Error('The file download did not complete');
+
+			return {
+				result: downloadRes,
+			};
+		} catch (error) {
+			const formattedError = {
+				result: {
+					message: error.message,
+				},
+			};
+
+			crashlytics.recordError(
+				error,
+				`Error at downloadAndFile: url: ${url} reason: ${error.message}`,
+			);
+
+			return Promise.reject(formattedError);
+		}
+	}
 }
 
 export default Request;

lib/utils/helpers.js

@@ -125,6 +125,8 @@ export const isArray = (arr) => !!(arr instanceof Array);
 
 export const isNumber = (num) => typeof num === 'number' && !Number.isNaN(Number(num));
 
+export const isFunction = (fn) => !!({}.toString.call(fn) === '[object Function]');
+
 export const promiseWrapper = (promise) =>
 	promise.then((data) => [data, null]).catch((error) => Promise.resolve([null, error]));