repl.builtinModules to module.builtinModules

Migrate from repl.builtinModules and repl._builtinLibs to module.builtinModules (DEP0191, DEP0142)

This recipe migrates code from the deprecated repl.builtinModules and repl._builtinLibs properties to the stable module.builtinModules API.

Deprecation

Node.js deprecated repl.builtinModules and repl._builtinLibs in favor of module.builtinModules.

See DEP0191 and DEP0142 for more details.

Usage

Run this codemod with:

npx codemod nodejs/repl-builtin-modules

Before/After

- import repl from 'node:repl';
+ import module from 'node:module';

- console.log(repl.builtinModules);
+ console.log(module.builtinModules);
- console.log(repl._builtinLibs);
+ console.log(module.builtinModules);

What It Does

• Replaces repl.builtinModules with module.builtinModules
• Replaces repl._builtinLibs with module.builtinModules
• Updates imports from node:repl to node:module when appropriate
• Works with both ESM and CommonJS patterns

Common Use Cases

Listing Built-in Modules

- const repl = require('node:repl');
+ const module = require('node:module');

- const builtins = repl.builtinModules;
+ const builtins = module.builtinModules;
  console.log(builtins);
  // ['fs', 'path', 'http', ...]

Checking if Module is Built-in

- import repl from 'node:repl';
+ import module from 'node:module';

  function isBuiltin(name) {
-   return repl.builtinModules.includes(name);
+   return module.builtinModules.includes(name);
  }

  console.log(isBuiltin('fs'));      // true
  console.log(isBuiltin('express')); // false

The property repl._builtinLibs was always a private API (prefixed with _). Always use module.builtinModules for stable, public access.

The module.builtinModules array includes all built-in Node.js modules like ‘fs’, ‘path’, ‘http’, ‘crypto’, etc. Use it to validate module names or build autocomplete features.