enhance(fets/internal): use the same EMPTY_OBJECT for proxies

Author: ardatan

.changeset/shiny-planets-do.md

@@ -0,0 +1,5 @@
+---
+"fets": patch
+---
+
+Use the same EMPTY_OBJECT for proxies

packages/fets/src/client/createClient.ts

@@ -1,6 +1,7 @@
 import { stringify as qsStringify, type IStringifyOptions } from 'qs';
 import { fetch, FormData } from '@whatwg-node/fetch';
 import { iterateAsyncVoid } from '@whatwg-node/server';
+import { EMPTY_OBJECT } from '../plugins/utils.js';
 import { HTTPMethod } from '../typed-fetch.js';
 import { OpenAPIDocument, Router, SecurityScheme } from '../types.js';
 import { createClientTypedResponsePromise } from './clientResponse.js';
@@ -54,8 +55,6 @@ function useValidationErrors(): ClientPlugin {
   };
 }
 
-const EMPTY_OBJECT = {};
-
 /**
  * Create a client for an OpenAPI document
  * You need to pass the imported OpenAPI document as a generic

packages/fets/src/createRouter.ts

@@ -5,6 +5,7 @@ import landingPageRaw from './landing-page.js';
 import { useDefineRoutes } from './plugins/define-routes.js';
 import { useOpenAPI } from './plugins/openapi.js';
 import { useTypeBox } from './plugins/typebox.js';
+import { EMPTY_OBJECT } from './plugins/utils.js';
 import { HTTPMethod, TypedRequest, TypedResponse } from './typed-fetch.js';
 import type {
   OnRouteHandleHook,
@@ -23,8 +24,6 @@ import type {
 } from './types.js';
 import { asyncIterationUntilReturn } from './utils.js';
 
-const EMPTY_OBJECT = {};
-
 export function createRouterBase(
   {
     fetchAPI: givenFetchAPI,

packages/fets/src/plugins/utils.ts

@@ -1,30 +1,29 @@
+export const EMPTY_OBJECT = Object.freeze({});
+
 export function getHeadersObj(headers: Headers): Record<string, string> {
-  return new Proxy(
-    {},
-    {
-      get(_target, prop: string) {
-        return headers.get(prop) || undefined;
-      },
-      set(_target, prop: string, value) {
-        headers.set(prop, value);
-        return true;
-      },
-      has(_target, prop: string) {
-        return headers.has(prop);
-      },
-      deleteProperty(_target, prop: string) {
-        headers.delete(prop);
-        return true;
-      },
-      ownKeys() {
-        return [...headers.keys()];
-      },
-      getOwnPropertyDescriptor() {
-        return {
-          enumerable: true,
-          configurable: true,
-        };
-      },
+  return new Proxy(EMPTY_OBJECT, {
+    get(_target, prop: string) {
+      return headers.get(prop) || undefined;
     },
-  );
+    set(_target, prop: string, value) {
+      headers.set(prop, value);
+      return true;
+    },
+    has(_target, prop: string) {
+      return headers.has(prop);
+    },
+    deleteProperty(_target, prop: string) {
+      headers.delete(prop);
+      return true;
+    },
+    ownKeys() {
+      return [...headers.keys()];
+    },
+    getOwnPropertyDescriptor() {
+      return {
+        enumerable: true,
+        configurable: true,
+      };
+    },
+  });
 }