diff --git a/frontend/vitest.setup.ts b/frontend/vitest.setup.ts
index 7a7a6f7b..507ae012 100644
--- a/frontend/vitest.setup.ts
+++ b/frontend/vitest.setup.ts
@@ -2,7 +2,7 @@ import '@testing-library/jest-dom';
 
 function createStorageMock() {
   const store = new Map<string, string>();
-  return {
+  const handler = {
     getItem: (key: string) => (store.has(key) ? store.get(key)! : null),
     setItem: (key: string, value: string) => {
       store.set(key, String(value));
@@ -18,6 +18,37 @@ function createStorageMock() {
       return store.size;
     },
   };
+
+  return new Proxy(handler, {
+    get(target, prop) {
+      if (prop === 'length') {
+        return store.size;
+      }
+      if (typeof prop === 'string' && !isNaN(Number(prop))) {
+        return Array.from(store.entries())[Number(prop)]?.[1] ?? null;
+      }
+      if (prop in target) {
+        return (target as any)[prop];
+      }
+      return store.get(String(prop)) ?? null;
+    },
+    ownKeys() {
+      return Array.from(store.keys());
+    },
+    getOwnPropertyDescriptor(target, prop) {
+      if (store.has(String(prop))) {
+        return {
+          configurable: true,
+          enumerable: true,
+          value: store.get(String(prop)),
+        };
+      }
+      if (prop in target) {
+        return Object.getOwnPropertyDescriptor(target, prop);
+      }
+      return undefined;
+    },
+  });
 }
 
 if (!window.localStorage || typeof window.localStorage.getItem !== 'function') {
diff --git a/testing/backend/test_crawler_plugin.py b/testing/backend/test_crawler_plugin.py
index 70419e84..93ef65d9 100644
--- a/testing/backend/test_crawler_plugin.py
+++ b/testing/backend/test_crawler_plugin.py
@@ -87,11 +87,10 @@ def test_crawler_target_field_requires_http_url():
     data = json.loads((PLUGIN_DIR / "metadata.json").read_text(encoding="utf-8"))
     fields = {f["id"]: f for f in data["fields"]}
     target_validation = fields["target"].get("validation", {})
-    uses_preset = target_validation.get("validation_type") == "url"
-    uses_pattern = "https?" in target_validation.get("pattern", "") or \
-                   "http" in target_validation.get("pattern", "")
-    assert uses_preset or uses_pattern, \
+    pattern = target_validation.get("pattern", "")
+    assert "https?" in pattern or "http" in pattern, (
         "target field must validate for HTTP(S) URL format"
+    )
 
 
 def test_crawler_has_optional_depth_field_with_default():