process.getBuiltinModule

process.getBuiltinModule(id): Object | undefined

process.getBuiltinModule(id) provides a way to load built-in modules in a globally available function. ES Modules that need to support other environments can use it to conditionally load a Node.js built-in when it is run in Node.js, without having to deal with the resolution error that can be thrown by import in a non-Node.js environment or having to use dynamic import() which either turns the module into an asynchronous module, or turns a synchronous API into an asynchronous one.

if (globalThis.process?.getBuiltinModule) {
  // Run in Node.js, use the Node.js fs module.
  const fs = globalThis.process.getBuiltinModule('fs');
  // If `require()` is needed to load user-modules, use createRequire()
  const module = globalThis.process.getBuiltinModule('module');
  const require = module.createRequire(import.meta.url);
  const foo = require('foo');
}

If id specifies a built-in module available in the current Node.js process, process.getBuiltinModule(id) method returns the corresponding built-in module. If id does not correspond to any built-in module, undefined is returned.

process.getBuiltinModule(id) accepts built-in module IDs that are recognized by module.isBuiltin(id). Some built-in modules must be loaded with the node: prefix, see built-in modules with mandatory node: prefix. The references returned by process.getBuiltinModule(id) always point to the built-in module corresponding to id even if users modify require.cache so that require(id) returns something else.