browserify

What is browserify?

Browserify is a tool for Node.js that enables developers to use the require() function from Node in the browser. It bundles up all of your JavaScript files and dependencies into a single file that can be served to the browser. It allows for modular code in the client-side environment by leveraging the CommonJS module pattern.

What are browserify's main functionalities?

Bundle modules for the browser

This feature allows you to bundle all your JavaScript files and dependencies into a single file. The code sample demonstrates how to create a bundle starting with 'main.js' and output it to 'bundle.js'.

const browserify = require('browserify');
const fs = require('fs');

let b = browserify();
b.add('main.js');
b.bundle().pipe(fs.createWriteStream('bundle.js'));

Transformations

Browserify can apply transformations to the files as they are added to the bundle. This is useful for tasks like compiling ES6 syntax to ES5 using Babel, as shown in the code sample.

const browserify = require('browserify');
const babelify = require('babelify');

browserify('./src/app.js')
  .transform(babelify, { presets: ['@babel/preset-env'] })
  .bundle()
  .pipe(process.stdout);

Plugins

Browserify can be extended with plugins that can add additional functionality. In the code sample, the watchify plugin is used to automatically re-bundle the file whenever changes are detected.

const browserify = require('browserify');
const watchify = require('watchify');

const b = browserify('./src/app.js', { plugin: [watchify] });
b.on('update', bundle);
function bundle() {
  b.bundle().pipe(fs.createWriteStream('bundle.js'));
}

Other packages similar to browserify

webpack

Webpack is a powerful module bundler that can transform front-end assets like HTML, CSS, and images where Browserify is strictly for JavaScript. Webpack also has a larger plugin ecosystem and can split bundles more efficiently.

parcel

Parcel is a web application bundler that offers a zero-configuration setup. It is faster than Browserify due to its multi-core processing capability and it also handles a variety of assets like HTML, CSS, and images out of the box.

rollup

Rollup is a module bundler for JavaScript which uses the new standardized format for code modules included in the ES6 revision. It is known for its efficient bundling, as it generates a smaller bundle by eliminating unused code (tree shaking).

README

Browserify

Make node-style require() work in the browser, as if by magic!

Just write an entry.js to start with some require()s in it:

var foo = require('./foo');

window.onload = function () {
    document.getElementById('result').innerHTML = foo(100);
};

and then a foo.js:

var bar = require('./bar');

module.exports = function (x) {
    return x * bar.coeff(x) + (x * 3 - 2)
};

and then a bar.js:

exports.coeff = function (x) {
    return Math.log(x) / Math.log(2) + 1;
};

Now you need to build this. You can either:

• use the browserify CLI tool
• use the middleware
• use the API

using the CLI tool

browserify entry.js -o browserify.js

Then just throw a <script src="/browserify.js"></script> into your HTML!

using the middleware

var express = require('express');
var app = express.createServer();
app.listen(8080);

var bundle = require('browserify')(__dirname + '/entry.js');
app.use(bundle);

Then just throw a <script src="/browserify.js"></script> into your HTML!

using the API

See below.

features at a glance

• use npm modules in the browser

• require()s work browser-side just as they do in node

• coffee script just works™ — just require('./beans.coffee') or whichever

• lots of node builtins just work™:

  • require('events')
  • require('path')
  • require('vm')
  • require('querystring')

• lots of ways to compile

• watch mode automatically recompiles your bundle when files change

command-line usage

Usage: browserify [entry files] {OPTIONS}

Options:
  --outfile, -o  Write the browserify bundle to this file.
                 If unspecified, browserify prints to stdout.                   
  --require, -r  A module name or file to bundle.require()
                 Optionally use a colon separator to set the target.            
  --entry, -e    An entry point of your app                                     
  --ignore, -i   Ignore a file                                                  
  --alias, -a    Register an alias with a colon separator: "to:from"
                 Example: --alias 'jquery:jquery-browserify'                    
  --cache, -c    Turn on caching at $HOME/.config/browserling/cache.json or use
                 a file for caching.
                                                                 [default: true]
  --plugin, -p   Use a plugin. Use a colon separator to specify additional
                 plugin arguments as a JSON string.
                 Example: --plugin 'fileify:["files","."]'                      
  --prelude      Include the code that defines require() in this bundle.
                                                      [boolean]  [default: true]
  --watch, -w    Watch for changes. The script will stay open and write updates
                 to the output every time any of the bundled files change.
                 This option only works in tandem with -o.                      
  --verbose, -v  Write out how many bytes were written in -o mode. This is
                 especially useful with --watch.                                
  --help, -h     Show this message                                              

Specify a parameter.

methods

var browserify = require('browserify');

var b = browserify(opts={})

Return a middleware with attached methods that will host up a browserified script at opts.mount or "/browserify.js" if unspecified.

opts may also contain these fields:

• require - calls b.require()
• ignore - calls b.ignore()
• entry - calls b.addEntry()
• filter - registers a "post" extension using b.register()
• watch - set watches on files, see below
• cache - turn on caching for AST traversals, see below

If opts is a string, it is interpreted as a require value.

Any query string after opts.mount will be ignored.

watch :: Boolean or Object

Set watches on files and automatically rebundle when a file changes.

This option defaults to false. If opts.watch is set to true, default watch arguments are assumed or you can pass in an object to pass along as the second parameter to fs.watchFile().

cache :: Boolean or String

If cache is a boolean, turn on caching at $HOME/.config/browserify/cache.json.

If cache is a string, turn on caching at the filename specified by cache.

bundle events

b bundles will also emit events.

'syntaxError', err

This event gets emitted when there is a syntax error somewhere in the build process. If you don't listen for this event, the error will be printed to stderr.

'bundle'

In watch mode, this event is emitted when a new bundle has been generated.

b.bundle()

Return the bundled source as a string.

b.require(file)

Require a file or files for inclusion in the bundle.

If file is an array, require each element in it.

If file is a non-array object, map an alias to a package name. For instance to be able to map require('jquery') to the jquery-browserify package, you can do:

b.require({ jquery : 'jquery-browserify' })

and the same thing in middleware-form:

browserify({ require : { jquery : 'jquery-browserify' } })

To mix alias objects with regular requires you could do:

browserify({ require : [ 'seq', { jquery : 'jquery-browserify' }, 'traverse' ])

In practice you won't need to b.require() very many files since all the require()s are read from each file that you require and automatically included.

b.ignore(file)

Omit a file or files from being included by the AST walk to hunt down require() statements.

b.addEntry(file)

Append a file to the end of the bundle and execute it without having to require() it.

Specifying an entry point will let you require() other modules without having to load the entry point in a <script> tag yourself.

If entry is an Array, concatenate these files together and append to the end of the bundle.

b.filter(fn)

Transform the source using the filter function fn(src). The return value of fn should be the new source.

b.register(ext, fn)

Register a handler to wrap extensions.

Wrap every file matching the extension ext with the function fn.

For every file included into the bundle fn gets called for matching file types as fn.call(b, body, file) for the bundle instance b and the file content string body. fn should return the new wrapped contents.

If ext is unspecified, execute the wrapper for every file.

If ext is 'post', execute the wrapper on the entire bundle.

If ext is 'pre', call the wrapper function with the bundle object before the source is generated.

If ext is an object, pull the extension from ext.extension and the wrapper function fn from ext.wrapper. This makes it easy to write plugins like fileify.

Coffee script support is just implemented internally as a .register() extension:

b.register('.coffee', function (body) {
    return coffee.compile(body);
});

b.use(fn)

Use a middleware plugin, fn. fn is called with the instance object b.

b.prepend(content)

Prepend unwrapped content to the beginning of the bundle.

b.append(content)

Append unwrapped content to the end of the bundle.

b.alias(to, from)

Alias a package name from another package name.

b.modified

Contains a Date object with the time the bundle was last modified. This field is useful in conjunction with the watch field described in the browserify() to generate unique <script> src values to force script reloading.

package.json

In order to resolve main files for projects, the package.json "main" field is read.

If a package.json has a "browserify" field, you can override the standard "main" behavior with something special just for browsers.

The "browserify" field can be a string that points to the browser-specific "main" file or it can be an object with a "main" field in it.

compatability

process

Browserify exports a faux process object with these attributes:

• nextTick(fn) - does setTimeout(fn, 0)
• title - set to 'browser' for browser code, 'node' in regular node code

require('events')

You can require('events').EventEmitter just like in node.js code.

require('vm')

All the goodness of node's require('vm') has been emulated with iframe trickery and eval() hacks.

require('path')

The posix functions from the path module have been included except for exists() and existsSync(). Just require('path')!

__dirname

The faux directory name, scrubbed of true directory information so as not to expose your filesystem organization.

__filename

The faux file path, scrubbed of true path information so as not to expose your filesystem organization.

recipes

use an npm module in the browser

First install a module:

npm install traverse

Then write an entry.js:

var traverse = require('traverse');
var obj = traverse({ a : 3, b : [ 4, 5 ] }).map(function (x) {
    if (typeof x === 'number') this.update(x * 100)
});
console.dir(obj);

then build it!

browserify entry.js -o bundle.js

then put it in your html

<script src="bundle.js"></script>

and the entry.js will just run and require('traverse') will just work™.

convert a node module into a browser require-able standalone file

Using npm >= 1.0 from the commandz line: Install the traverse package locally (into the node_modules folder)

npm install traverse

Utilize browserify to... browserify the package

npm install -g browserify
browserify --require traverse -o bundle.js

Look at the files! There is a new one: bundle.js. Now go into HTML land:

<script src="bundle.js"></script>
<script> 
   var traverse = require('traverse');
</script>

read more

browserify: browser-side require() for your node.js

ad-hoc browserify CDN!

jquery-browserify

install

Using npm just do:

npm install browserify

to install into your project's node_modules directory, or if you want to use the command-line tool, install globally with:

npm install -g browserify