refactor: improve requestWithURL

Author: pi0

src/utils/request.ts

@@ -11,25 +11,21 @@ import type { HTTPMethod } from "../types/h3.ts";
 import type { H3EventContext } from "../types/context.ts";
 import type { ServerRequest } from "srvx";
 
-const _urlOverrides = new WeakMap<Request, string>();
-
-const _proxyHandler: ProxyHandler<Request> = {
-  get(target, prop, receiver) {
-    if (prop === "url") return _urlOverrides.get(receiver);
-    const value = Reflect.get(target, prop);
-    return typeof value === "function" ? value.bind(target) : value;
-  },
-};
-
 /**
  * Create a lightweight request proxy that overrides only the URL.
  *
  * Avoids cloning the original request (no `new Request()` allocation).
  */
 export function requestWithURL(req: ServerRequest, url: string): ServerRequest {
-  const proxy = new Proxy(req, _proxyHandler);
-  _urlOverrides.set(proxy, url);
-  return proxy;
+  const cache: Record<string | symbol, unknown> = { url };
+  return new Proxy(req, {
+    get(target, prop) {
+      if (prop in cache) return cache[prop];
+      const value = Reflect.get(target, prop);
+      cache[prop] = typeof value === "function" ? value.bind(target) : value;
+      return cache[prop];
+    },
+  });
 }
 
 /**

test/bench/request-proxy.ts

@@ -0,0 +1,54 @@
+import { bench, summary, compact, run } from "mitata";
+import { requestWithURL } from "../../src/utils/request.ts";
+
+const req = new Request("http://localhost:3000/base/path?q=1", {
+  method: "POST",
+  headers: { "content-type": "application/json", "x-custom": "value" },
+  body: JSON.stringify({ hello: "world" }),
+});
+
+// Pre-warmed proxy (cache populated)
+const warmed = requestWithURL(req, "http://localhost:3000/path?q=1");
+warmed.method;
+warmed.headers;
+
+compact(() => {
+  summary(() => {
+    bench("new Request(url, req)", () => {
+      const url = new URL(req.url);
+      url.pathname = url.pathname.slice("/base".length) || "/";
+      return new Request(url, req);
+    });
+
+    bench("requestWithURL(req, url)", () => {
+      return requestWithURL(req, "http://localhost:3000/path?q=1");
+    });
+  });
+
+  summary(() => {
+    bench("req.url", () => req.url);
+    bench("proxied.url (cached)", () => warmed.url);
+  });
+
+  summary(() => {
+    bench("req.method", () => req.method);
+    bench("proxied.method (cold)", () => {
+      const p = requestWithURL(req, "http://localhost:3000/path?q=1");
+      return p.method;
+    });
+    bench("proxied.method (cached)", () => warmed.method);
+  });
+
+  summary(() => {
+    bench("req.headers.get()", () => req.headers.get("content-type"));
+    bench("proxied.headers.get() (cold)", () => {
+      const p = requestWithURL(req, "http://localhost:3000/path?q=1");
+      return p.headers.get("content-type");
+    });
+    bench("proxied.headers.get() (cached)", () =>
+      warmed.headers.get("content-type"),
+    );
+  });
+});
+
+await run({ throw: true });