nodeWrapper.ts

/**
 * This file wraps the implementation of register so all modules `require()`-ed
 * internally within register are stored in a separate module cache.
 * This prevents un-transformed modules being stored in global module cache,
 * and allows register to transform these modules if they are loaded externally.
 */

// @ts-ignore todo(flow->ts) convert to esm
const Module = require("module");

const globalModuleCache = Module._cache;
const internalModuleCache = Object.create(null);

Module._cache = internalModuleCache;
const node = require("./node");

// NOTE: This Module._cache set is intercepted by the beforeEach hook in
// packages/babel-register/test/index.js to install dependencies mocks.
Module._cache = globalModuleCache;

// Add source-map-support to global cache as it's stateful
const smsPath = require.resolve("source-map-support");
globalModuleCache[smsPath] = internalModuleCache[smsPath];

const register = node.default;
register();

module.exports = node;