ReactFreshBabelPlugin.js — react Source File

Source Code

/**
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

'use strict';

export default function (babel, opts = {}) {
  if (typeof babel.env === 'function') {
    // Only available in Babel 7.
    const env = babel.env();
    if (env !== 'development' && !opts.skipEnvCheck) {
      throw new Error(
        'React Refresh Babel transform should only be enabled in development environment. ' +
          'Instead, the environment is: "' +
          env +
          '". If you want to override this check, pass {skipEnvCheck: true} as plugin options.',
      );
    }
  }

  const {types: t} = babel;
  const refreshReg = t.identifier(opts.refreshReg || '$RefreshReg$');
  const refreshSig = t.identifier(opts.refreshSig || '$RefreshSig$');

  const registrationsByProgramPath = new Map();
  function createRegistration(programPath, persistentID) {
    const handle = programPath.scope.generateUidIdentifier('c');
    if (!registrationsByProgramPath.has(programPath)) {
      registrationsByProgramPath.set(programPath, []);
    }
    const registrations = registrationsByProgramPath.get(programPath);
    registrations.push({
      handle,
      persistentID,
    });
    return handle;
  }

  function isComponentishName(name) {
    return typeof name === 'string' && name[0] >= 'A' && name[0] <= 'Z';
  }

  function findInnerComponents(inferredName, path, callback) {
    const node = path.node;
    switch (node.type) {
      case 'Identifier': {
        if (!isComponentishName(node.name)) {
          return false;
        }
        // export default hoc(Foo)
        // const X = hoc(Foo)
        callback(inferredName, node, null);
        return true;
      }
      case 'FunctionDeclaration': {
        // function Foo() {}
        // export function Foo() {}
// ... (802 more lines)