Lionel CommonJS Bundler

Common errors

• TypeError: commonJSBundler is not a function

  cause Attempting to call `commonJSBundler()` directly as a function, instead of accessing its methods like `makeCode` or `makeFile`.
  fix Ensure you are calling methods on the `commonJSBundler` object, e.g., `commonJSBundler.makeCode(content, dir)`.

• Error: Cannot find module 'lionel-commonjs-bundler'

  cause Incorrect import path or failure to specify the `index` entry point for the CommonJS module. Or, trying to use ESM `import` with a CJS-only package.
  fix Use the exact CommonJS `require` path as specified: `require('lionel-commonjs-bundler/index')`. If using `import`, it will not work as this package is CJS-only.

• Error: EACCES: permission denied, open 'output.js'

  cause The Node.js process does not have sufficient write permissions to create or modify the output file at the specified path.
  fix Check the permissions of the directory where the output file is being written. Run your script with appropriate permissions or choose an output path in a user-writable directory.

Warnings

• gotcha The package has not been updated in approximately three years. This may mean it lacks support for newer JavaScript language features (ESM, top-level await, etc.) or security patches for its dependencies, which could be critical for production use.
  Fix: Evaluate alternatives like Webpack, Rollup, or Esbuild for projects requiring active maintenance, modern features, or broader ecosystem compatibility.
• gotcha This bundler is specifically designed for CommonJS modules. It does not support ES Modules (ESM) syntax (`import`/`export`) as input. Attempting to bundle ESM will likely result in parsing errors or incorrect output.
  Fix: Ensure all input source code uses CommonJS `require()` and `module.exports` syntax. For projects requiring ESM, consider alternative bundlers that explicitly support it.
• gotcha The bundler emphasizes simplicity with 'not much configuration options'. This lack of advanced configuration (e.g., extensive plugin ecosystem, granular optimization, tree-shaking) might limit its applicability for complex bundling scenarios or custom requirements found in larger applications.
  Fix: For projects with complex needs, consider bundlers like Webpack, Rollup, or Parcel that offer extensive configuration and plugin capabilities. Understand the limitations before committing to this bundler.
• deprecated While CommonJS itself is not deprecated in Node.js, the shift towards ES Modules is significant, with tools and libraries increasingly adopting ESM. Using a bundler exclusively for CJS might lead to interoperability issues with newer dependencies.
  Fix: For new projects, strongly consider using bundlers and module systems (ESM) that align with current JavaScript ecosystem trends to ensure future compatibility and access to modern features.

Install

• npm install lionel-commonjs-bundler npm
• yarn add lionel-commonjs-bundler yarn
• pnpm add lionel-commonjs-bundler pnpm

Imports

• commonJSBundler
  wrong:

  import { commonJSBundler } from 'lionel-commonjs-bundler'; // ESM import will not work, also incorrect path

  correct:

  const { commonJSBundler } = require('lionel-commonjs-bundler/index');

  The library is exclusively CommonJS. Direct ESM `import` statements are not supported. The entry point is specifically `/index`.
• makeCode
  wrong:

  const bundle = require('lionel-commonjs-bundler').makeCode(content, dir); // May lead to undefined if `commonJSBundler` isn't the direct default export.

  correct:

  const { commonJSBundler } = require('lionel-commonjs-bundler/index');
  const bundle = commonJSBundler.makeCode(content, dir);

  Access `makeCode` as a method of the named export `commonJSBundler`.
• makeFile
  wrong:

  import { makeFile } from 'lionel-commonjs-bundler/index'; // ESM import will not work.

  correct:

  const { commonJSBundler } = require('lionel-commonjs-bundler/index');
  const bundle = commonJSBundler.makeFile(filePath, dir);

  Like `makeCode`, `makeFile` is a method accessed via the `commonJSBundler` named export.

Quickstart

Demonstrates how to use `makeFile` to bundle a CommonJS JavaScript file along with its local dependencies into a single browser-compatible string.

const { commonJSBundler } = require('lionel-commonjs-bundler/index');
const path = require('path');

const contentOfFile = `
  const dep = require('./dependency');
  module.exports = 'Hello ' + dep;
`;

const dependencyContent = `
  module.exports = 'World';
`;

// Create dummy files for demonstration
const fs = require('fs');
const tempDir = path.join(__dirname, 'temp_bundler_test');
if (!fs.existsSync(tempDir)) fs.mkdirSync(tempDir);
fs.writeFileSync(path.join(tempDir, 'main.js'), contentOfFile);
fs.writeFileSync(path.join(tempDir, 'dependency.js'), dependencyContent);

try {
  const bundle = commonJSBundler.makeFile(path.join(tempDir, 'main.js'), tempDir);
  console.log('Successfully bundled code:\n', bundle);
  // Expected output (minified): 'var dep=require("./dependency");module.exports="Hello "+dep;' (after resolution)
} catch (error) {
  console.error('Bundling failed:', error);
} finally {
  // Clean up dummy files
  fs.unlinkSync(path.join(tempDir, 'main.js'));
  fs.unlinkSync(path.join(tempDir, 'dependency.js'));
  fs.rmdirSync(tempDir);
}