fix(react-integration-tester): remove Yarn Classic flags from yarn install command

Author: mainframev

tools/react-integration-tester/src/__tests__/cli.e2e.test.ts

@@ -133,7 +133,6 @@ describe('rit CLI e2e', () => {
     expect(yarn).toBeTruthy();
     expect(yarn?.cwd).toContain('tmp/rit/react-18');
 
-    expect(existsSync(join(fs.tempDir, 'tmp/rit/.yarn-cache'))).toBeTruthy();
     expect(readJSON(join(fs.tempDir, 'tmp/rit/react-18/package.json'))).toMatchInlineSnapshot(`
       Object {
         "dependencies": Object {

tools/react-integration-tester/src/setup.ts

@@ -272,22 +272,18 @@ function prepareTsConfigTemplate(options: {
   };
 }
 
-async function installDependenciesAtReactRoot(reactVersionRootPath: string, opts: { scaffoldRoot: string }) {
-  // Use a scoped global yarn cache and a global mutex to avoid concurrent cache corruption on CI
-  const yarnCacheFolder = join(opts.scaffoldRoot, '.yarn-cache');
-
+async function installDependenciesAtReactRoot(reactVersionRootPath: string) {
   if (!existsSync(join(reactVersionRootPath, 'package.json'))) {
     throw new Error(`Missing package.json at react root: ${reactVersionRootPath}`);
   }
 
-  mkdirSync(yarnCacheFolder, { recursive: true });
   // small retry loop
   const maxAttempts = 3;
   let attempt = 0;
   while (true) {
     try {
       attempt += 1;
-      await runCmd(`yarn install --mutex network --network-timeout 60000 --cache-folder ${yarnCacheFolder}`, {
+      await runCmd(`yarn install`, {
         cwd: reactVersionRootPath,
       });
       break;
@@ -334,7 +330,7 @@ async function ensureDependencies(params: {
 
     case 'run-install': {
       params.logger.verbose(`Installing dependencies for React ${params.react}...`);
-      await installDependenciesAtReactRoot(params.reactRootPath, { scaffoldRoot: params.mode.scaffoldRoot });
+      await installDependenciesAtReactRoot(params.reactRootPath);
       return;
     }
   }
@@ -527,7 +523,7 @@ export async function installDepsForReactVersion(
 
   logger.verbose(`Installing dependencies under: ${reactRootPath}`);
 
-  await installDependenciesAtReactRoot(reactRootPath, { scaffoldRoot });
+  await installDependenciesAtReactRoot(reactRootPath);
 
   logger.log(`Dependencies installed under shared react root -> ${reactRootPath}.`);
 }