const FileSpliterMerger = require('file-splitter-merger');

const fileSpliterMerger = new FileSpliterMerger();
const filePart = 1024 * 1024; // split file for 1 MB = 1024 * 1024
const format = '{file}.{index}'; // optional format default to "{file}.{index}"
const files = fileSpliterMerger.split('/path/file.zip', filePart, format);
// return files splitted

const fileSpliterMerger = new FileSpliterMerger();
const filePath = '/path/file.zip'; // file to search parts for
const format = '{file}.{index}'; // optional format default to "{file}.{index}"
const files = await fileSpliterMerger.findParts(filePath, format);
const destination = '/path/new-file.zip';
fileSpliterMerger.merge(files, destination);

FileSpliterMerger.defaultFormat = '{file}_{index}';