test(web): assert partial-create passes fieldsError state to the edit route

web/src/objects/object-new-page.test.tsx

@@ -2,17 +2,23 @@ import { expect, test } from "vitest";
 import { screen, waitFor } from "@testing-library/react";
 import userEvent from "@testing-library/user-event";
 import { http, HttpResponse } from "msw";
-import { Routes, Route } from "react-router-dom";
+import { Routes, Route, useLocation } from "react-router-dom";
 import { server } from "../test/server";
 import { renderApp } from "../test/render";
 import { ObjectNewPage } from "./object-new-page";
 
+function EditStub() {
+  const location = useLocation();
+  const flagged = (location.state as { fieldsError?: boolean } | null)?.fieldsError === true;
+  return <div>edit page{flagged ? " (fields error)" : ""}</div>;
+}
+
 function tree() {
   return (
     <Routes>
       <Route path="/objects/new" element={<ObjectNewPage />} />
       <Route path="/objects/:id" element={<div>detail view</div>} />
-      <Route path="/objects/:id/edit" element={<div>edit page</div>} />
+      <Route path="/objects/:id/edit" element={<EditStub />} />
     </Routes>
   );
 }
@@ -61,5 +67,5 @@ test("partial create: fields PUT fails -> navigate to edit with an error banner"
   await userEvent.type(screen.getByLabelText(/inscription/i), "x");
   await userEvent.click(screen.getByRole("button", { name: /create object/i }));
 
-  await waitFor(() => expect(screen.getByText("edit page")).toBeInTheDocument());
+  await waitFor(() => expect(screen.getByText(/edit page \(fields error\)/i)).toBeInTheDocument());
 });