add test to validate that foreach throws on a dictionary (#5467)

integration-tests/tests/src/tests/dictionary.ts

@@ -199,6 +199,14 @@ describe("Dictionary", () => {
       });
     }
 
+    it("iterating with forEach() throws", function (this: RealmContext) {
+      const item = this.realm.write(() => {
+        return this.realm.create<Item>("Item", {});
+      });
+      //@ts-expect-error accesses forEach on a dictionary which should not exist.
+      expect(() => item.dict.forEach()).throws(TypeError, "item.dict.forEach is not a function");
+    });
+
     it("can store string values using string keys", function (this: RealmContext) {
       const item = this.realm.write(() => {
         const item = this.realm.create<Item>("Item", {});