worker.js

/**
 * Copyright (c) 2014-present, Facebook, Inc. All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 *
 * @flow
 */

import type {SerializableError} from 'types/TestResult';
import type {HasteImpl, WorkerMessage, WorkerCallback} from './types';

import path from 'path';
import docblock from 'jest-docblock';
import fs from 'graceful-fs';
import H from './constants';
import extractRequires from './lib/extract_requires';

const JSON_EXTENSION = '.json';
const PACKAGE_JSON = path.sep + 'package' + JSON_EXTENSION;

let hasteImpl: ?HasteImpl = null;
let hasteImplModulePath: ?string = null;

const formatError = (error: string | Error): SerializableError => {
  if (typeof error === 'string') {
    return {
      message: error,
      stack: null,
      type: 'Error',
    };
  }

  return {
    code: error.code || undefined,
    message: error.message,
    stack: error.stack,
    type: 'Error',
  };
};

// Cannot be ESM export or worker-farm is confused
module.exports = (data: WorkerMessage, callback: WorkerCallback): void => {
  if (
    data.hasteImplModulePath &&
    data.hasteImplModulePath !== hasteImplModulePath
  ) {
    if (hasteImpl) {
      throw new Error('jest-haste-map: hasteImplModulePath changed');
    }
    hasteImplModulePath = data.hasteImplModulePath;
    hasteImpl =
      // $FlowFixMe: dynamic require
      (require(hasteImplModulePath): HasteImpl);
  }

  try {
    const filePath = data.filePath;
    const content = fs.readFileSync(filePath, 'utf8');
    let module;
    let id;
    let dependencies;

    if (filePath.endsWith(PACKAGE_JSON)) {
      const fileData = JSON.parse(content);
      if (fileData.name) {
        id = fileData.name;
        module = [filePath, H.PACKAGE];
      }
    } else if (!filePath.endsWith(JSON_EXTENSION)) {
      if (hasteImpl) {
        id = hasteImpl.getHasteName(filePath);
      } else {
        const doc = docblock.parse(docblock.extract(content));
        id = doc.providesModule || doc.provides;
      }
      dependencies = extractRequires(content);
      if (id) {
        module = [filePath, H.MODULE];
      }
    }

    callback(null, {dependencies, id, module});
  } catch (error) {
    callback(formatError(error));
  }
};