package-exports-test.js

/**
 * 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.
 *
 * @flow strict-local
 * @format
 * @oncall react_native
 */

import Resolver from '../index';
import {createResolutionContext} from './utils';

describe('with package exports resolution disabled', () => {
  test('should ignore "exports" field', () => {
    const context = {
      ...createResolutionContext({
        '/root/src/main.js': '',
        '/root/node_modules/test-pkg/package.json': JSON.stringify({
          main: 'index.js',
          exports: './index-exports.js',
        }),
        '/root/node_modules/test-pkg/index.js': '',
        '/root/node_modules/test-pkg/index-exports.js': '',
      }),
      originModulePath: '/root/src/main.js',
      unstable_enablePackageExports: false,
      unstable_realPath: null,
    };

    expect(Resolver.resolve(context, 'test-pkg', null)).toEqual({
      type: 'sourceFile',
      filePath: '/root/node_modules/test-pkg/index.js',
    });
  });
});

describe('with package exports resolution enabled', () => {
  describe('main entry point', () => {
    const baseContext = {
      ...createResolutionContext({
        '/root/src/main.js': '',
        '/root/node_modules/test-pkg/package.json': '',
        '/root/node_modules/test-pkg/index.js': '',
        '/root/node_modules/test-pkg/index-main.js': '',
        '/root/node_modules/test-pkg/index-exports.js.js': '',
        '/root/node_modules/test-pkg/index-exports.android.js': '',
      }),
      originModulePath: '/root/src/main.js',
      unstable_enablePackageExports: true,
    };

    test('should resolve package using "exports" field', () => {
      const context = {
        ...baseContext,
        getPackage: () => ({
          main: 'index-main.js',
          exports: {
            '.': './index.js',
          },
        }),
      };

      expect(Resolver.resolve(context, 'test-pkg', null)).toEqual({
        type: 'sourceFile',
        filePath: '/root/node_modules/test-pkg/index.js',
      });
    });

    test('should resolve package using "exports" field (shorthand)', () => {
      const context = {
        ...baseContext,
        getPackage: () => ({
          main: 'index-main.js',
          exports: './index.js',
        }),
      };

      expect(Resolver.resolve(context, 'test-pkg', null)).toEqual({
        type: 'sourceFile',
        filePath: '/root/node_modules/test-pkg/index.js',
      });
    });

    test('should fall back to "main" field resolution when file does not exist', () => {
      const context = {
        ...baseContext,
        getPackage: () => ({
          main: 'index-main.js',
          exports: './foo.js',
        }),
      };

      expect(Resolver.resolve(context, 'test-pkg', null)).toEqual({
        type: 'sourceFile',
        filePath: '/root/node_modules/test-pkg/index-main.js',
      });
      // TODO(T142200031): Assert that an invalid package warning is logged with
      // file missing message
    });

    test('should fall back to "main" field resolution when "exports" is an invalid subpath', () => {
      const context = {
        ...baseContext,
        getPackage: () => ({
          main: 'index-main.js',
          exports: 'index.js',
        }),
      };

      expect(Resolver.resolve(context, 'test-pkg', null)).toEqual({
        type: 'sourceFile',
        filePath: '/root/node_modules/test-pkg/index-main.js',
      });
      // TODO(T142200031): Assert that an invalid package warning is logged with
      // invalid subpath value message
    });

    describe('should resolve "exports" target directly', () => {
      const context = {
        ...baseContext,
        getPackage: () => ({
          main: 'index-main.js',
          exports: './index-exports.js',
        }),
      };

      test('without expanding `sourceExts`', () => {
        expect(Resolver.resolve(context, 'test-pkg', null)).toEqual({
          type: 'sourceFile',
          filePath: '/root/node_modules/test-pkg/index-main.js',
        });
      });

      test('without expanding platform-specific extensions', () => {
        expect(Resolver.resolve(context, 'test-pkg', 'android')).toEqual({
          type: 'sourceFile',
          filePath: '/root/node_modules/test-pkg/index-main.js',
        });
      });
    });
  });

  describe('conditional exports', () => {
    describe('main entry point', () => {
      const baseContext = {
        ...createResolutionContext({
          '/root/src/main.js': '',
          '/root/node_modules/test-pkg/package.json': '',
          '/root/node_modules/test-pkg/index.js': '',
          '/root/node_modules/test-pkg/index-browser.js': '',
        }),
        originModulePath: '/root/src/main.js',
        unstable_enablePackageExports: true,
      };

      test('should resolve main entry point using conditional exports', () => {
        const context = {
          ...baseContext,
          unstable_conditionNames: ['browser', 'import', 'require'],
          getPackage: () => ({
            main: 'index-main.js',
            exports: {
              '.': {
                browser: './index-browser.js',
                default: './index.js',
              },
            },
          }),
        };

        expect(Resolver.resolve(context, 'test-pkg', null)).toEqual({
          type: 'sourceFile',
          filePath: '/root/node_modules/test-pkg/index-browser.js',
        });
      });

      test('should resolve main entry point when root keys are a condition mapping (shorthand)', () => {
        const context = {
          ...baseContext,
          unstable_conditionNames: ['browser', 'import', 'require'],
          getPackage: () => ({
            main: 'index-main.js',
            exports: {
              browser: './index-browser.js',
              default: './index.js',
            },
          }),
        };

        expect(Resolver.resolve(context, 'test-pkg', null)).toEqual({
          type: 'sourceFile',
          filePath: '/root/node_modules/test-pkg/index-browser.js',
        });
      });
    });
  });
});