Refactor Jest configuration and enhance testing utilities

- Removed Node version checks and related module name mappings from jest.config.js to simplify configuration.
- Cleaned up jest.setup.js by removing the mock for fetch that converted Node's Readable stream to a web-standard ReadableStream.
- Introduced new utility functions in testUtils.js for creating Node.js Readable streams and retrieving the Node version.
- Added new tests for fetch functionality that validate streaming behavior with Readable streams.
- Created emptyForTesting.js to facilitate testing in environments where certain modules need to be mocked.

These changes improve the clarity and maintainability of the testing setup in the react-on-rails and react-on-rails-pro packages.

Author: AbanoubGhadban

packages/react-on-rails/tests/emptyForTesting.js renamed to packages/react-on-rails-pro/tests/emptyForTesting.js

@@ -1,8 +1,6 @@
 // eslint-disable-next-line import/no-relative-packages
 import rootConfig from '../../jest.config.base.js';
 
-const nodeVersion = parseInt(process.version.slice(1), 10);
-
 // Package-specific Jest configuration
 // Inherits from root jest.config.mjs and adds package-specific settings
 export default {
@@ -15,17 +13,6 @@ export default {
   // Package-specific: Jest setup files
   setupFiles: ['<rootDir>/tests/jest.setup.js'],
 
-  // Package-specific: Module name mapping for React Server Components
-  // Only mock modules on Node versions < 18 where RSC features aren't available
-  moduleNameMapper:
-    nodeVersion < 18
-      ? {
-          'react-on-rails-rsc/client': '<rootDir>/tests/emptyForTesting.js',
-          '^@testing-library/dom$': '<rootDir>/tests/emptyForTesting.js',
-          '^@testing-library/react$': '<rootDir>/tests/emptyForTesting.js',
-        }
-      : {},
-
   // Set root directory to current package
   rootDir: '.',
 };

packages/react-on-rails/tests/fixtures/rsc-payloads/simple-shell-with-async-component/chunk1.json renamed to packages/react-on-rails-pro/tests/fixtures/rsc-payloads/simple-shell-with-async-component/chunk1.json

@@ -14,32 +14,8 @@ if (typeof window !== 'undefined') {
   // eslint-disable-next-line global-require
   const { TextEncoder, TextDecoder } = require('util');
   // eslint-disable-next-line global-require
-  const { Readable } = require('stream');
-  // eslint-disable-next-line global-require
   const { ReadableStream, ReadableStreamDefaultReader } = require('stream/web');
 
-  // Mock the fetch function to return a ReadableStream instead of Node's Readable stream
-  // This matches browser behavior where fetch responses have ReadableStream bodies
-  // Node's fetch and polyfills like jest-fetch-mock return Node's Readable stream,
-  // so we convert it to a web-standard ReadableStream for consistency
-  // Note: Node's Readable stream exists in node 'stream' built-in module, can be imported as `import { Readable } from 'stream'`
-  jest.mock('../src/utils', () => ({
-    ...jest.requireActual('../src/utils'),
-    fetch: (...args) =>
-      jest
-        .requireActual('../src/utils')
-        .fetch(...args)
-        .then((res) => {
-          const originalBody = res.body;
-          if (originalBody instanceof Readable) {
-            Object.defineProperty(res, 'body', {
-              value: Readable.toWeb(originalBody),
-            });
-          }
-          return res;
-        }),
-  }));
-
   global.TextEncoder = TextEncoder;
   global.TextDecoder = TextDecoder;