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browserify
Advanced tools
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.
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'));
}
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 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 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).
require('modules')
in the browser
Use a node-style require()
to organize your browser code
and load modules installed by npm.
browserify will recursively analyze all the require()
calls in your app in
order to build a bundle you can serve up to the browser in a single <script>
tag.
If you're new to browserify, check out the browserify handbook and the resources on browserify.org.
Whip up a file, main.js
with some require()
s in it. You can use relative
paths like './foo.js'
and '../lib/bar.js'
or module paths like 'gamma'
that will search node_modules/
using
node's module lookup algorithm.
var foo = require('./foo.js');
var bar = require('../lib/bar.js');
var gamma = require('gamma');
var elem = document.getElementById('result');
var x = foo(100) + bar('baz');
elem.textContent = gamma(x);
Export functionality by assigning onto module.exports
or exports
:
module.exports = function (n) { return n * 111 }
Now just use the browserify
command to build a bundle starting at main.js
:
$ browserify main.js > bundle.js
All of the modules that main.js
needs are included in the bundle.js
from a
recursive walk of the require()
graph using
required.
To use this bundle, just toss a <script src="bundle.js"></script>
into your
html!
With npm do:
npm install browserify
Usage: browserify [entry files] {OPTIONS}
Standard 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 Replace a file with an empty stub. Files can be globs.
--exclude, -u Omit a file from the output bundle. Files can be globs.
--external, -x Reference a file from another bundle. Files can be globs.
--transform, -t Use a transform module on top-level files.
--command, -c Use a transform command on top-level files.
--standalone -s Generate a UMD bundle for the supplied export name.
This bundle works with other module systems and sets the name
given as a window global if no module system is found.
--debug -d Enable source maps that allow you to debug your files
separately.
--help, -h Show this message
For advanced options, type `browserify --help advanced`.
Specify a parameter.
Advanced Options:
--insert-globals, --ig, --fast [default: false]
Skip detection and always insert definitions for process, global,
__filename, and __dirname.
benefit: faster builds
cost: extra bytes
--insert-global-vars, --igv
Comma-separated list of global variables to detect and define.
Default: __filename,__dirname,process,Buffer,global
--detect-globals, --dg [default: true]
Detect the presence of process, global, __filename, and __dirname and define
these values when present.
benefit: npm modules more likely to work
cost: slower builds
--ignore-missing, --im [default: false]
Ignore `require()` statements that don't resolve to anything.
--noparse=FILE
Don't parse FILE at all. This will make bundling much, much faster for giant
libs like jquery or threejs.
--no-builtins
Turn off builtins. This is handy when you want to run a bundle in node which
provides the core builtins.
--no-commondir
Turn off setting a commondir. This is useful if you want to preserve the
original paths that a bundle was generated with.
--no-bundle-external
Turn off bundling of all external modules. This is useful if you only want
to bundle your local files.
--bare
Alias for both --no-builtins, --no-commondir, and sets --insert-global-vars
to just "__filename,__dirname". This is handy if you want to run bundles in
node.
--no-browser-field, --no-bf
Turn off package.json browser field resolution. This is also handy if you
need to run a bundle in node.
--transform-key
Instead of the default package.json#browserify#transform field to list
all transforms to apply when running browserify, a custom field, like, e.g.
package.json#browserify#production or package.json#browserify#staging
can be used, by for example running:
* `browserify index.js --transform-key=production > bundle.js`
* `browserify index.js --transform-key=staging > bundle.js`
--node
Alias for --bare and --no-browser-field.
--full-paths
Turn off converting module ids into numerical indexes. This is useful for
preserving the original paths that a bundle was generated with.
--deps
Instead of standard bundle output, print the dependency array generated by
module-deps.
--no-dedupe
Turn off deduping.
--list
Print each file in the dependency graph. Useful for makefiles.
--extension=EXTENSION
Consider files with specified EXTENSION as modules, this option can used
multiple times.
--global-transform=MODULE, -g MODULE
Use a transform module on all files after any ordinary transforms have run.
--ignore-transform=MODULE, -it MODULE
Do not run certain transformations, even if specified elsewhere.
--plugin=MODULE, -p MODULE
Register MODULE as a plugin.
Passing arguments to transforms and plugins:
For -t, -g, and -p, you may use subarg syntax to pass options to the
transforms or plugin function as the second parameter. For example:
-t [ foo -x 3 --beep ]
will call the `foo` transform for each applicable file by calling:
foo(file, { x: 3, beep: true })
Many npm modules that don't do IO will just work after being browserified. Others take more work.
Many node built-in modules have been wrapped to work in the browser, but only
when you explicitly require()
or use their functionality.
When you require()
any of these modules, you will get a browser-specific shim:
Additionally, if you use any of these variables, they will be defined in the bundled output in a browser-appropriate way:
You can just as easily create a bundle that will export a require()
function so
you can require()
modules from another script tag. Here we'll create a
bundle.js
with the through
and duplexer modules.
$ browserify -r through -r duplexer -r ./my-file.js:my-module > bundle.js
Then in your page you can do:
<script src="bundle.js"></script>
<script>
var through = require('through');
var duplexer = require('duplexer');
var myModule = require('my-module');
/* ... */
</script>
If you prefer the source maps be saved to a separate .js.map
source map file, you may use
exorcist in order to achieve that. It's as simple as:
$ browserify main.js --debug | exorcist bundle.js.map > bundle.js
Learn about additional options here.
If browserify finds a require
d function already defined in the page scope, it
will fall back to that function if it didn't find any matches in its own set of
bundled modules.
In this way, you can use browserify to split up bundles among multiple pages to
get the benefit of caching for shared, infrequently-changing modules, while
still being able to use require()
. Just use a combination of --external
and
--require
to factor out common dependencies.
For example, if a website with 2 pages, beep.js
:
var robot = require('./robot.js');
console.log(robot('beep'));
and boop.js
:
var robot = require('./robot.js');
console.log(robot('boop'));
both depend on robot.js
:
module.exports = function (s) { return s.toUpperCase() + '!' };
$ browserify -r ./robot.js > static/common.js
$ browserify -x ./robot.js beep.js > static/beep.js
$ browserify -x ./robot.js boop.js > static/boop.js
Then on the beep page you can have:
<script src="common.js"></script>
<script src="beep.js"></script>
while the boop page can have:
<script src="common.js"></script>
<script src="boop.js"></script>
This approach using -r
and -x
works fine for a small number of split assets,
but there are plugins for automatically factoring out components which are
described in the
partitioning section of the browserify handbook.
You can use the API directly too:
var browserify = require('browserify');
var b = browserify();
b.add('./browser/main.js');
b.bundle().pipe(process.stdout);
var browserify = require('browserify')
browserify([files] [, opts])
Returns a new browserify instance.
files
and opts
are both optional, but must be in the order shown if both are
passed.
Entry files may be passed in files
and / or opts.entries
.
External requires may be specified in opts.require
, accepting the same formats
that the files
argument does.
If an entry file is a stream, its contents will be used. You should pass
opts.basedir
when using streaming files so that relative requires can be
resolved.
opts.entries
has the same definition as files
.
opts.noParse
is an array which will skip all require() and global parsing for
each file in the array. Use this for giant libs like jquery or threejs that
don't have any requires or node-style globals but take forever to parse.
opts.transform
is an array of transform functions or modules names which will
transform the source code before the parsing.
opts.ignoreTransform
is an array of transformations that will not be run,
even if specified elsewhere.
opts.plugin
is an array of plugin functions or module names to use. See the
plugins section below for details.
opts.extensions
is an array of optional extra extensions for the module lookup
machinery to use when the extension has not been specified.
By default browserify considers only .js
and .json
files in such cases.
opts.basedir
is the directory that browserify starts bundling from for
filenames that start with .
.
opts.paths
is an array of directories that browserify searches when looking
for modules which are not referenced using relative path. Can be absolute or
relative to basedir
. Equivalent of setting NODE_PATH
environmental variable
when calling browserify
command.
opts.commondir
sets the algorithm used to parse out the common paths. Use
false
to turn this off, otherwise it uses the
commondir module.
opts.fullPaths
disables converting module ids into numerical indexes. This is
useful for preserving the original paths that a bundle was generated with.
opts.builtins
sets the list of built-ins to use, which by default is set in
lib/builtins.js
in this distribution.
opts.bundleExternal
boolean option to set if external modules should be
bundled. Defaults to true.
When opts.browserField
is false, the package.json browser field will be
ignored. When opts.browserField
is set to a string
, then a custom field name
can be used instead of the default "browser"
field.
When opts.insertGlobals
is true, always insert process
, global
,
__filename
, and __dirname
without analyzing the AST for faster builds but
larger output bundles. Default false.
When opts.detectGlobals
is true, scan all files for process
, global
,
__filename
, and __dirname
, defining as necessary. With this option npm
modules are more likely to work but bundling takes longer. Default true.
When opts.ignoreMissing
is true, ignore require()
statements that don't
resolve to anything.
When opts.debug
is true, add a source map inline to the end of the bundle.
This makes debugging easier because you can see all the original files if
you are in a modern enough browser.
When opts.standalone
is a non-empty string, a standalone module is created
with that name and a umd wrapper.
You can use namespaces in the standalone global export using a .
in the string
name as a separator, for example 'A.B.C'
. The global export will be sanitized
and camel cased.
Note that in standalone mode the require()
calls from the original source will
still be around, which may trip up AMD loaders scanning for require()
calls.
You can remove these calls with
derequire:
$ npm install derequire
$ browserify main.js --standalone Foo | derequire > bundle.js
opts.insertGlobalVars
will be passed to
insert-module-globals
as the opts.vars
parameter.
opts.externalRequireName
defaults to 'require'
in expose
mode but you can
use another name.
opts.bare
creates a bundle that does not include Node builtins, and does not
replace global Node variables except for __dirname
and __filename
.
opts.node
creates a bundle that runs in Node and does not use the browser
versions of dependencies. Same as passing { bare: true, browserField: false }
.
Note that if files do not contain javascript source code then you also need to specify a corresponding transform for them.
All other options are forwarded along to module-deps and browser-pack directly.
Add an entry file from file
that will be executed when the bundle loads.
If file
is an array, each item in file
will be added as an entry file.
Make file
available from outside the bundle with require(file)
.
The file
param is anything that can be resolved by require.resolve()
,
including files from node_modules
. Like with require.resolve()
, you must
prefix file
with ./
to require a local file (not in node_modules
).
file
can also be a stream, but you should also use opts.basedir
so that
relative requires will be resolvable.
If file
is an array, each item in file
will be required.
In file
array form, you can use a string or object for each item. Object items
should have a file
property and the rest of the parameters will be used for
the opts
.
Use the expose
property of opts to specify a custom dependency name.
require('./vendor/angular/angular.js', {expose: 'angular'})
enables require('angular')
Bundle the files and their dependencies into a single javascript file.
Return a readable stream with the javascript file contents or
optionally specify a cb(err, buf)
to get the buffered results.
Prevent file
from being loaded into the current bundle, instead referencing
from another bundle.
If file
is an array, each item in file
will be externalized.
If file
is another bundle, that bundle's contents will be read and excluded
from the current bundle as the bundle in file
gets bundled.
Prevent the module name or file at file
from showing up in the output bundle.
If file
is an array, each item in file
will be ignored.
Instead you will get a file with module.exports = {}
.
Prevent the module name or file at file
from showing up in the output bundle.
If file
is an array, each item in file
will be excluded.
If your code tries to require()
that file it will throw unless you've provided
another mechanism for loading it.
Transform source code before parsing it for require()
calls with the transform
function or module name tr
.
If tr
is a function, it will be called with tr(file)
and it should return a
through-stream
that takes the raw file contents and produces the transformed source.
If tr
is a string, it should be a module name or file path of a
transform module
with a signature of:
var through = require('through');
module.exports = function (file) { return through() };
You don't need to necessarily use the through module. Browserify is compatible with the newer, more verbose Transform streams built into Node v0.10.
Here's how you might compile coffee script on the fly using .transform()
:
var coffee = require('coffee-script');
var through = require('through');
b.transform(function (file) {
var data = '';
return through(write, end);
function write (buf) { data += buf }
function end () {
this.queue(coffee.compile(data));
this.queue(null);
}
});
Note that on the command-line with the -c
flag you can just do:
$ browserify -c 'coffee -sc' main.coffee > bundle.js
Or better still, use the coffeeify module:
$ npm install coffeeify
$ browserify -t coffeeify main.coffee > bundle.js
If opts.global
is true
, the transform will operate on ALL files, despite
whether they exist up a level in a node_modules/
directory. Use global
transforms cautiously and sparingly, since most of the time an ordinary
transform will suffice. You can also not configure global transforms in a
package.json
like you can with ordinary transforms.
Global transforms always run after any ordinary transforms have run.
Transforms may obtain options from the command-line with subarg syntax:
$ browserify -t [ foo --bar=555 ] main.js
or from the api:
b.transform('foo', { bar: 555 })
In both cases, these options are provided as the second argument to the transform function:
module.exports = function (file, opts) { /* opts.bar === 555 */ }
Options sent to the browserify constructor are also provided under
opts._flags
. These browserify options are sometimes required if your transform
needs to do something different when browserify is run in debug mode, for
example.
Register a plugin
with opts
. Plugins can be a string module name or a
function the same as transforms.
plugin(b, opts)
is called with the browserify instance b
.
For more information, consult the plugins section below.
There is an internal labeled-stream-splicer pipeline with these labels:
'record'
- save inputs to play back later on subsequent bundle()
calls'deps'
- module-deps'json'
- adds module.exports=
to the beginning of json files'unbom'
- remove byte-order markers'unshebang'
- remove #! labels on the first line'syntax'
- check for syntax errors'sort'
- sort the dependencies for deterministic bundles'dedupe'
- remove duplicate source contents'label'
- apply integer labels to files'emit-deps'
- emit 'dep'
event'debug'
- apply source maps'pack'
- browser-pack'wrap'
- apply final wrapping, require=
and a newline and semicolonYou can call b.pipeline.get()
with a label name to get a handle on a stream pipeline
that you can push()
, unshift()
, or splice()
to insert your own transform
streams.
Reset the pipeline back to a normal state. This function is called automatically
when bundle()
is called multiple times.
This function triggers a 'reset' event.
browserify uses the package.json
in its module resolution algorithm, just like
node. If there is a "main"
field, browserify will start resolving the package
at that point. If there is no "main"
field, browserify will look for an
"index.js"
file in the module root directory. Here are some more
sophisticated things you can do in the package.json:
There is a special "browser" field you can set in your package.json on a per-module basis to override file resolution for browser-specific versions of files.
For example, if you want to have a browser-specific module entry point for your
"main"
field you can just set the "browser"
field to a string:
"browser": "./browser.js"
or you can have overrides on a per-file basis:
"browser": {
"fs": "level-fs",
"./lib/ops.js": "./browser/opts.js"
}
Note that the browser field only applies to files in the local module, and like
transforms, it doesn't apply into node_modules
directories.
You can specify source transforms in the package.json in the
browserify.transform
field. There is more information about how source
transforms work in package.json on the
module-deps readme.
For example, if your module requires brfs, you can add
"browserify": { "transform": [ "brfs" ] }
to your package.json. Now when somebody require()
s your module, brfs will
automatically be applied to the files in your module without explicit
intervention by the person using your module. Make sure to add transforms to
your package.json dependencies field.
When a file is resolved for the bundle, the bundle emits a 'file'
event with
the full file
path, the id
string passed to require()
, and the parent
object used by
browser-resolve.
You could use the file
event to implement a file watcher to regenerate bundles
when files change.
When a package file is read, this event fires with the contents. The package
directory is available at pkg.__dirname
.
When .bundle()
is called, this event fires with the bundle
output stream.
When the .reset()
method is called or implicitly called by another call to
.bundle()
, this event fires.
When a transform is applied to a file, the 'transform'
event fires on the
bundle stream with the transform stream tr
and the file
that the transform
is being applied to.
For some more advanced use-cases, a transform is not sufficiently extensible. Plugins are modules that take the bundle instance as their first parameter and an option hash as their second.
Plugins can be used to do perform some fancy features that transforms can't do.
For example, factor-bundle is a
plugin that can factor out common dependencies from multiple entry-points into a
common bundle. Use plugins with -p
and pass options to plugins with
subarg syntax:
browserify x.js y.js -p [ factor-bundle -o bundle/x.js -o bundle/y.js ] \
> bundle/common.js
For a list of plugins, consult the browserify-plugin tag on npm.
There is a wiki page that lists the known browserify transforms.
If you write a transform, make sure to add your transform to that wiki page and
add a package.json keyword of browserify-transform
so that
people can browse for all the browserify
transforms on npmjs.org.
There is a wiki page that lists the known browserify tools.
If you write a tool, make sure to add it to that wiki page and
add a package.json keyword of browserify-tool
so that
people can browse for all the browserify
tools on npmjs.org.
Releases are documented in changelog.markdown and on the browserify twitter feed.
FAQs
browser-side require() the node way
The npm package browserify receives a total of 994,025 weekly downloads. As such, browserify popularity was classified as popular.
We found that browserify demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 40 open source maintainers collaborating on the project.
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Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.
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