Test fetch function only with node version 18+

Author: AbanoubGhadban

node_package/tests/RSCClientRoot.test.jsx

@@ -14,17 +14,15 @@ import { render, screen, act } from '@testing-library/react';
 import '@testing-library/jest-dom';
 import path from 'path';
 import fs from 'fs';
-import { createNodeReadableStream } from './testUtils';
+import { createNodeReadableStream, getNodeVersion } from './testUtils';
 
 import RSCClientRoot, { resetRenderCache } from '../src/RSCClientRoot';
 
 enableFetchMocks();
 
-const nodeVersion = parseInt(process.version.slice(1), 10);
-
 // React Server Components tests are not compatible with Experimental React 18 and React 19
 // That only run with node version 18 and above
-(nodeVersion >= 18 ? describe : describe.skip)('RSCClientRoot', () => {
+(getNodeVersion() >= 18 ? describe : describe.skip)('RSCClientRoot', () => {
   beforeEach(() => {
     jest.clearAllMocks();
 

node_package/tests/testUtils.js

@@ -8,7 +8,6 @@ import { Readable } from 'stream';
  *   push: (chunk: any) => void
  * }} Object containing the stream and push function
  */
-// eslint-disable-next-line import/prefer-default-export
 export const createNodeReadableStream = () => {
   const pendingChunks = [];
   let pushFn;
@@ -31,3 +30,5 @@ export const createNodeReadableStream = () => {
 
   return { stream, push };
 };
+
+export const getNodeVersion = () => parseInt(process.version.slice(1), 10);

node_package/tests/utils.test.js

@@ -1,11 +1,14 @@
 import { enableFetchMocks } from 'jest-fetch-mock';
 
 import { fetch } from '../src/utils';
-import { createNodeReadableStream } from './testUtils';
+import { createNodeReadableStream, getNodeVersion } from './testUtils';
 
 enableFetchMocks();
 
-describe('fetch', () => {
+// The fetch mock functionality that returns a ReadableStream is not supported in Node.js v16.
+// Additionally, fetch function is used in RSCClientRoot only that is compatible with Node.js v18+,
+// so these tests are conditionally skipped on older Node versions.
+(getNodeVersion() >= 18 ? describe : describe.skip)('fetch', () => {
   it('streams body as ReadableStream', async () => {
     // create Readable stream that emits 5 chunks with 10ms delay between each chunk
     const { stream, push } = createNodeReadableStream();