Node.js Core Libraries for Browsers

Common errors

• Module not found: Error: Can't resolve 'fs' in '/path/to/your/project'

  cause Attempting to import a Node.js core module (like `fs`, `net`, `child_process`) that `node-libs-browser-okam` does not provide a browser polyfill for (its entry in the exported object is `null`).
  fix Remove the problematic import from your browser-side code. These modules are fundamentally tied to the Node.js environment and typically cannot be replicated in a browser. Re-evaluate your architecture if such functionality is critical for the client.

• TypeError: Buffer.from is not a function

  cause Code expects the `Buffer.from()` static method, but `node-libs-browser-okam` uses an older `feross/buffer@4.x` polyfill which predates this API, primarily supporting `new Buffer()`.
  fix Refactor your code to use `new Buffer(array)` or `new Buffer(string, encoding)` instead of `Buffer.from()`. Alternatively, you can configure your bundler to alias `buffer` to a different, more modern polyfill that supports `Buffer.from()`.

• ReferenceError: process is not defined

  cause The global `process` object, expected by some Node.js modules, is not correctly aliased to its browser polyfill by the bundler, or accessed in a context where the polyfill isn't available.
  fix Ensure your bundler (e.g., Webpack, Rollup, Browserify) has `node-libs-browser-okam` or a similar polyfill configured to correctly alias the global `process` object. For Webpack, this often involves configuring `resolve.fallback` or `ProvidePlugin` for older versions.

• Uncaught TypeError: crypto.createHash is not a function

  cause While `crypto` has a browser polyfill, it may not implement all functions available in Node.js's native `crypto` module, leading to runtime errors for unsupported APIs.
  fix Review the specific `crypto` function being called. If it's not implemented, you'll need to find a dedicated browser-compatible cryptography library that provides the required functionality, or refactor your code to avoid the unsupported API.

Warnings

• deprecated The `node-libs-browser` project is officially deprecated and only accepts bug fixes. No new features or breaking changes will be introduced. Users should consider modern alternatives for polyfilling Node.js built-ins in browser environments, or ensure their bundler explicitly handles these.
  Fix: Review your project's dependency on `node-libs-browser-okam` and explore more actively maintained polyfills or ensure your bundler (e.g., Webpack 5+) has native fallbacks or custom resolutions configured.
• gotcha The `buffer` implementation uses `feross/buffer@4.x` instead of the newer `5.x` version. This is due to a deliberate choice to support older browsers (like IE9) by avoiding reliance on typed arrays. Consequently, `Buffer.from()` and other modern `Buffer` static methods are not available.
  Fix: If your code requires `Buffer.from()` or other modern `Buffer` APIs, you may need to explicitly import a newer `buffer` polyfill or use an alternative method like `new Buffer()` (which is deprecated in Node.js itself but works with this polyfill).
• gotcha The `punycode` implementation uses `bestiejs/punycode.js@1.x`, which requires older JavaScript engines. This means it may not be compatible with newer `punycode` APIs or expectations of modern JavaScript syntax.
  Fix: If specific modern `punycode` functionalities are required, consider importing a more up-to-date `punycode` polyfill directly rather than relying on the one provided by `node-libs-browser-okam`.
• gotcha Many Node.js core modules, such as `child_process`, `cluster`, `dgram`, `fs`, `module`, `net`, `readline`, `repl`, `tls`, do not have browser-compatible implementations within this package. Their entries in the exported object are `null`.
  Fix: Avoid importing these Node.js-specific modules in browser code. If their functionality is critical, you must find entirely different browser-native solutions or refactor your application logic.

Install

• npm install node-libs-browser-okam npm
• yarn add node-libs-browser-okam yarn
• pnpm add node-libs-browser-okam pnpm

Imports

• nodeLibs
  wrong:

  import { nodeLibs } from 'node-libs-browser-okam';

  correct:

  import nodeLibs from 'node-libs-browser-okam';

  The package exports a default object containing paths to browser polyfills. Named imports are incorrect.
• nodeLibs

  const nodeLibs = require('node-libs-browser-okam');

  CommonJS `require` is the most common way to import this package due to its age and common usage in bundler configurations.
• bufferPath
  wrong:

  import { buffer } from 'node-libs-browser-okam';

  correct:

  const bufferPath = require('node-libs-browser-okam').buffer;

  Individual module paths are accessed as properties on the default exported object.

Quickstart

Demonstrates importing the object of Node.js browser libraries and iterating through the available polyfill paths, highlighting how a bundler might resolve a module like 'buffer'.

import nodeLibs from 'node-libs-browser-okam';

console.log('Available Node.js browser libs:');

for (const libName in nodeLibs) {
  const libPath = nodeLibs[libName];
  if (libPath) {
    console.log(`- ${libName}: ${libPath}`);
  } else {
    console.log(`- ${libName}: (No browser implementation available)`);
  }
}

// Example: How a bundler might use it to resolve 'buffer'
const resolvedBufferPath = nodeLibs.buffer;
if (resolvedBufferPath) {
  console.log(`\nPath to buffer polyfill: ${resolvedBufferPath}`);
} else {
  console.log('\nBuffer polyfill not found.');
}

// This package is primarily used by bundlers like Webpack for automatic aliasing.
// For direct usage, you would typically configure a bundler to use these paths.