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$ npm i savery --save


// ES2015+
import savery from 'savery';
// CommonJS
const savery = require('savery');
// script
const savery = window.savery;
// save the file immediately with a single line'.foo { display: block; }', 'foo.css');
// or create use the partial applcation function option with name and options
const saveCssFile = savery('foo.css', {
    onBeforeSave() {
// and then pass it the data
const file = saveCssFile('.foo { display: block; }');; // to execute the creation of the file from the data
file.abort(); // if you want to abort the request to create the file
// all save executions are chainable'.foo { display: block; }', 'foo.css')
    .then((saveryInstance) => {
        console.log('I am complete! Here is the instance to prove it: ', saveryInstance);
    .catch((saveryInstance) => {
        console.log('Oops, something went wrong. :(');
        throw saveryInstance.error;

As you can see, you can either call to immediately fire the save process, or you can create a partial function which accepts filename and saveryOptions but returns a function that accepts the data. The reason for the partial function is the ability for reuse. For example, if you know the file type and want a consistent filename from a remote download:

import axios from 'axios';
import savery from 'savery';
const PDF_NAME = 'my-consistently-named.pdf';
// save the consistent implementation
const pdfFileSavery = savery(PDF_NAME);
// create a function that accepts the data and calls the .save()
const savePdfFile = (data) => {
  return pdfFileSavery(data).save();
// in your API call, you can pass it as a simple method
const getPdf = () => {
    method: 'get',
    responseType: 'arraybuffer',
    uri: '/location/of/pdf'

Or if you needed to support a dynamic filename, it could still be a simple one-liner:

import axios from 'axios';
import savery from 'savery';
// create a function that accepts the data and calls the .save()
const savePdfFile = (name, options = {}) => {
  const saveryInstance = savery(name, options);
  return (data) => {
    return saveryInstance(data).save();
// in your API call, you can pass it as a simple method
const getPdf = (dynamicFilename) => {
    method: 'get',
    responseType: 'arraybuffer',
    uri: '/location/of/pdf'

With the partial applcation function usage, you have control over the execution while still maximizing code reuse and readability.


savery(filename: string = 'download.txt', saveryOptions: Object = {}): saveryInstance

The savery function accepts the filename and options parameter, both with defaults. It returns a saveryInstance that has the attributes passed applied.


  onAbort: ?Function,
  onAfterSave: ?Function,
  onBeforeSave: ?Function,
  onError: ?Function,
  onStartSave: ?Function,
  onEndSave: ?Function,
  shouldAutoBom: ?boolean = true,
  type: ?string

All saveryOptions properties are optional, and type specifically will default to being intuited from the filename extension and that extension's standard MIME type. The shouldAutoBom feature automatically provides Unicode text encoding hints (see byte-order mark for more details). Promise

This will execute the saving of the file, and return the Promise of the file's processing. This allows you to chain the results:

const saveryInstance = savery('foo.txt');
  .then((instance) => {
    console.log(instance); // instance after completion
  .catch((instance) => {
    console.log(instance); // instance after the error completion
    console.error(instance.error); // completion error

The lifecycle methods shown above in options are fired as part of the save process in the order expected:

  • onBeforeSave (before all other execution)
  • onStartSave (before blob is created)
  • onEndSave (after blob is created and save is attempted)
  • onAfterSave (after all other execution)

saveryInstance.abort(): void

This will abort the instance execution immediately. This fires two methods in the order shown:

  • onAbort (immediately upon aborting)
  • onError (once aborted, internally it fires the onError so that the .catch() in the chain is also called) any, filename: string = 'download.txt', saveryOptions: Object = {}): Promise

This will immediate trigger the save process with the data, filename, and saveryOptions passed, and will return the same Promise that calling save() on a saveryInstance will.

Advanced usage

savery uses a list of commonly-used MIME types which is intended to be comprehensive enough for most common use cases, however if you want to include the complete list of MIME types in your package you can do either of the following:

  • Build systems (webpack, browserify, etc.)
    • Add the SAVERY=full environment variable to the command that runs your build script
  • <script> tag
    • Use the savery-full script instead of the savery script

This will tell savery to use the mime-types package instead of the local list.

Supported browsers

  • Full support
    • Firefox 20+
    • Chrome
    • Edge
    • Internet Explorer 10+
    • Opera 15+
  • Partial support (filenames not supported)
    • Firefox <20
    • Safari
    • Opera <15
  • Requires Blob polyfill
    • Firefox <20
    • Opera <15
    • Safari <6

Please note that it is highly recommended to include a Promise polyfill, as it will be needed for savery to work in the following environments:

  • IE 10/11
  • IE Mobile 10/11
  • Safari <7.1
  • iOS Safari <8
  • Android browser <4.4.4

Additional information

The data property in savery will accept anything for use in the Blob construction, however canvas elements specifically need to have the data converted by the canvas.toBlob() method prior to calling via savery.


Standard stuff, clone the repo and npm install dependencies. The npm scripts available:

  • build => run webpack to build savery-full.js with NODE_ENV=development
  • build:lite => run webpack to build savery.js with NODE_ENV=development
  • build:minifed => run webpack to build savery-full.min.js with NODE_ENV=production
  • build:minifed:lite => run webpack to build savery.min.js with NODE_ENV=production
  • dev => run webpack dev server to run example app based on full MIME type map provided by mime-types package
  • dev:lite => run webpack dev server to run example app based on local lite MIME type map
  • flow => run flowtype analysis on src folder
  • lint => run ESLint against all files in the src folder
  • prepublish => run lint, test, transpile, build, and build-minified
  • test => run AVA test functions with NODE_ENV=test
  • test:watch => same as test, but runs persistent watcher
  • transpile => run babel against all files in src to create files in lib



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