resolve-test.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.
 *
 * @emails oncall+jsinfra
 */

'use strict';

const fs = require('fs');
const path = require('path');
const ModuleMap = require('jest-haste-map').ModuleMap;
const Resolver = require('../');

describe('isCoreModule', () => {
  it('returns false if `hasCoreModules` is false.', () => {
    const moduleMap = new ModuleMap();
    const resolver = new Resolver(moduleMap, {
      hasCoreModules: false,
    });
    const isCore = resolver.isCoreModule('assert');
    expect(isCore).toEqual(false);
  });

  it('returns true if `hasCoreModules` is true and `moduleName` is a core module.', () => {
    const moduleMap = new ModuleMap();
    const resolver = new Resolver(moduleMap, {});
    const isCore = resolver.isCoreModule('assert');
    expect(isCore).toEqual(true);
  });

  it('returns false if `hasCoreModules` is true and `moduleName` is not a core module.', () => {
    const moduleMap = new ModuleMap();
    const resolver = new Resolver(moduleMap, {});
    const isCore = resolver.isCoreModule('not-a-core-module');
    expect(isCore).toEqual(false);
  });
});

describe('findNodeModule', () => {
  it('is possible to override the default resolver', () => {
    const cwd = process.cwd();
    const resolvedCwd = fs.realpathSync(cwd) || cwd;
    const nodePaths = process.env.NODE_PATH
      ? process.env.NODE_PATH
          .split(path.delimiter)
          .filter(Boolean)
          .map(p => path.resolve(resolvedCwd, p))
      : null;

    jest.mock('../__mocks__/userResolver');
    const userResolver = require('../__mocks__/userResolver');
    userResolver.mockImplementation(() => 'module');

    const newPath = Resolver.findNodeModule('test', {
      basedir: '/',
      browser: true,
      extensions: ['js'],
      moduleDirectory: ['node_modules'],
      paths: ['/something'],
      resolver: require.resolve('../__mocks__/userResolver'),
    });

    expect(newPath).toBe('module');
    expect(userResolver.mock.calls[0][0]).toBe('test');
    expect(userResolver.mock.calls[0][1]).toEqual({
      basedir: '/',
      browser: true,
      extensions: ['js'],
      moduleDirectory: ['node_modules'],
      paths: (nodePaths || []).concat(['/something']),
    });
  });
});