Switch back to Node's url.parse for cleaner handling of partial URLs.

packages/dev-middleware/src/inspector-proxy/InspectorProxy.js

@@ -94,15 +94,7 @@ export default class InspectorProxy implements InspectorProxyQueries {
     response: ServerResponse,
     next: (?Error) => mixed,
   ) {
-    // When request.url is a relative path, the WHATWG URL constructor will require
-    // the second "base" param otherwise an exception will be thrown.
-    // We could use `http://${request.headers.host}` here instead however:
-    //  - We are forced to make an assumption about the scheme so if someone is running
-    //    Metro over https it could cause confusion.
-    //
-    //  - We are only extracting pathname from the parsed URL so the host portion is
-    //    irrelevant.
-    const pathname = new URL(request.url, 'http://example').pathname;
+    const pathname = url.parse(request.url).pathname;
     if (
       pathname === PAGES_LIST_JSON_URL ||
       pathname === PAGES_LIST_JSON_URL_2