cjs-faker
v0.1.0
Published
Fakes commonJS boilerplate to allow importing legacy code as an ES6 module
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cjs-faker fakes commonJS and AMD boilerplate to allow importing legacy code via ES6 modules.
This is implemented by providing fake exports
/module.exports
, require()
and define()
calls that are used by the commonJS or AMD code being included.
You must shim all modules that you depend on.
Rationale
This approach is mostly a thought experiment in evaluating legacy code at runtime, rather than requiring a build step (as require()
and define()
are not supported natively by browsers).
For most practical purposes, you'll be better off using Rollup with its commonJS plugin. Using Rollup requires a build step before you can import legacy code as an ES6 module, but doesn't require a shim per module in the dependency tree.
Usage
Usage requires providing a shim around all commonJS or AMD modules:
// wrap_base64.js
import faker from './node_modules/cjs-faker/cjs-faker.js';
import 'https://cdn.rawgit.com/mathiasbynens/base64/a8d7cabd/base64.js';
export default faker('base64');
Now you can just use the base64
module inside ES6:
import base64 from './wrap_base64.js';
console.info(base64.encode('Hello!'));
// or use require() itself for already wrapped modules
const base64 = require('base64');
No build steps are required.
Dependency Tree
If you depend on commonJS module A, which depends on commonJS module B etc, you must provide the shim for B first, then A.
The default faker
method in the examples fills a registry that is available via the global require()
call, so B has to be shimmed first for A's require('a')
call to succeed.
See file B:
// wrap_b.js
import faker from './node_modules/cjs-faker/cjs-faker.js';
import './path/to/b.js';
export default faker('b');
And file A:
// wrap_a.js
import faker from './node_modules/cjs-faker/cjs-faker.js';
import './path/to/a.js';
export default faker('a');