fixup! dont if cant

Author: erights

packages/non-trapping-shim/shim.js

@@ -2,21 +2,25 @@
 import { getEnvironmentOption } from '@endo/env-options';
 import { ReflectPlus, ObjectPlus, ProxyPlus } from './src/non-trapping-pony.js';
 
+const { isFrozen } = Object;
+
 const nonTrappingShimOption = getEnvironmentOption(
   'SES_NON_TRAPPING_SHIM',
   'disabled',
   ['enabled'],
 );
 
 if (nonTrappingShimOption === 'enabled') {
-  // TODO figure this out, either remove directive or change to
-  // at-ts-expect-error.
-  // @ts-ignore type of ReflectPlus vs Reflect, I think
-  globalThis.Reflect = ReflectPlus;
+  if (![Reflect, Object, Object.prototype, Proxy].some(isFrozen)) {
+    // TODO figure this out, either remove directive or change to
+    // at-ts-expect-error.
+    // @ts-ignore type of ReflectPlus vs Reflect, I think
+    globalThis.Reflect = ReflectPlus;
 
-  globalThis.Object = ObjectPlus;
-  // eslint-disable-next-line no-extend-native
-  Object.prototype.constructor = ObjectPlus;
+    globalThis.Object = ObjectPlus;
+    // eslint-disable-next-line no-extend-native
+    Object.prototype.constructor = ObjectPlus;
 
-  globalThis.Proxy = ProxyPlus;
+    globalThis.Proxy = ProxyPlus;
+  }
 }