esbuild-plugin-polyfill-node

ESBuild plugin to polyfill Node.js built-ins and globals, geared towards edge environments and Deno (including Deno Deploy). It consists of two plugins: polyfillNode, which should work for most cases, and polyfillNodeForDeno which targets Deno and Deno Deploy specifically.

Installation

npm install esbuild-plugin-polyfill-node

polyfillNode

Usage

import { build } from "esbuild";
import { polyfillNode } from "esbuild-plugin-polyfill-node";

build({
	entryPoints: ["src/index.js"],
	bundle: true,
	outfile: "dist/bundle.js",
	plugins: [
		polyfillNode({
			// Options (optional)
		}),
	],
});

Options

• globals.buffer: Whether to inject the Buffer global. Disable it to prevent code like if (typeof Buffer !== "undefined") from pulling in the (quite large) buffer-es6 polyfill. Default: true.
• globals.process: Whether to inject the process global. Disable it to prevent process.env.NODE_ENV from pulling in the process-es6 polyfill. You can use the define option to replace process.env.NODE_ENV instead. Default: true.
• polyfills: Polyfills to inject. It's an object where the keys are the names of the polyfills and the values are false, true, or "empty". false disables the polyfill, true enables it, and "empty" injects an empty polyfill.

Implemented polyfills

• _buffer_list as implemented in readable-stream
• _stream_passthrough as implemented in readable-stream
• _stream_readable as implemented in readable-stream
• _stream_transform as implemented in readable-stream
• _stream_writable as implemented in readable-stream
• assert as implemented in assert
• buffer as implemented in buffer-es6
• console as implemented in console-browserify
• crypto¹ as implemented in crypto-browserify
• domain as implemented in domain-browser
• events as implemented in events
• fs¹ as implemented in browserify-fs
• http as implemented in stream-http
• https as implemented in stream-http
• os as implemented in os
• path as implemented in path
• process as implemented in process-es6
• punycode as implemented in punycode
• querystring as implemented in querystring
• stream as implemented in stream
• string_decoder as implemented in string_decoder
• sys as implemented in util
• timers as implemented in timers-browserify
• tty as implemented in tty-browserify
• url as implemented in url
• util as implemented in util
• vm as implemented in vm-browserify
• zlib as implemented in browserify-zlib

¹ All except crypto and fs polyfills are on by default. crypto and fs have to be explicitly enabled. Otherwise, they will be replaced with empty stubs.

Empty stubs

The followings modules are only provided as empty stubs. It is illegal to pass true for them.

• dns
• dgram
• child_process
• cluster
• module
• net
• readline
• repl
• tls

Globals

• global (aliased to globalThis)
• process¹ (imports the process module)
• Buffer¹ (imports the buffer module)
• __dirname (always "/")
• __filename (always "/index.js")

¹ process and Buffer shims can be disabled by passing globals.process: false and globals.buffer: false to the plugin options.

polyfillNodeForDeno

This plugin uses Deno's std/node library to polyfill Node builtins and globals. Optionally, it can use polyfills from NPM instead.

Usage

import { build } from "esbuild";
import { polyfillNodeForDeno } from "esbuild-plugin-polyfill-node";

build({
	entryPoints: ["src/index.js"],
	bundle: true,
	outfile: "dist/bundle.js",
	plugins: [
		polyfillNodeForDeno({
			// Options (optional)
		}),
	],
});

Options

• stdVersion: Version of the Deno standard library to use. Default: "0.160.0".
• globals: Whether to inject global polyfills (process, Buffer, setImmediate, clearImmediate, __dirname, and __filename). Default: true.
• polyfills: Polyfills to inject. It's an object where the keys are the names of the polyfills and the values are false, true, "npm" or "empty". false disables the polyfill, true enables it (default where exists), "npm" injects a polyfill from the NPM (default for "domain", "punycode", "vm", and "zlib"), and "empty" injects an empty polyfill (default for missing polyfills).

Credits

• Fatih Aygün, under the MIT license
• Loosely based on rollup-plugin-polyfill-node