Fixed the change to switch to the fallback

manangarg21 · manangarg21 · commit a3417b54ff93 · 2025-10-16T19:46:22.000+05:30
diff --git a/packages/jest-util/src/__tests__/installCommonGlobals.test.ts b/packages/jest-util/src/__tests__/installCommonGlobals.test.ts
@@ -48,3 +48,13 @@ it('turns a V8 global object into a Node global object', () => {
 
   expect(fake).toHaveBeenCalledTimes(1);
 });
+
+it('overrides process.features.require_module to false when present', () => {
+  const myGlobal = installCommonGlobals(getGlobal(), {});
+
+  // Some Node versions may not expose the flag; only assert if present
+  const features = (myGlobal.process as any).features;
+  if (features && Object.prototype.hasOwnProperty.call(features, 'require_module')) {
+    expect(features.require_module).toBe(false);
+  }
+});
diff --git a/packages/jest-util/src/createProcessObject.ts b/packages/jest-util/src/createProcessObject.ts
@@ -117,5 +117,32 @@ export default function createProcessObject(): typeof Process {
     },
   });
 
+  // Ensure feature flags reflect Jest's capabilities inside the VM.
+  // Node may expose `process.features.require_module` which signals that
+  // requiring ESM via `require()` is supported. Jest's runtime does not
+  // support requiring ESM modules through CJS `require`, so we override
+  // the flag to false to allow defensive code paths to behave correctly.
+  //
+  const features: unknown = (newProcess as any).features;
+  if (features && typeof features === 'object') {
+    // Only override if the host process exposes the flag
+    if ('require_module' in (features as Record<string, unknown>)) {
+      try {
+        Object.defineProperty(features as object, 'require_module', {
+          configurable: true,
+          enumerable: true,
+          get: () => false,
+        });
+      } catch {
+        // If redefining fails for any reason, fall back to direct assignment
+        try {
+          (features as any).require_module = false;
+        } catch {
+          // ignore if we cannot override
+        }
+      }
+    }
+  }
+
   return newProcess;
 }
