test(vendors): preserve draft on roster load failure

src/test/app/(protected)/vendors/use-vendor-roster-form.test.tsx

@@ -1,6 +1,7 @@
 import { act, renderHook, waitFor } from "@testing-library/react";
 import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 import type { ReactNode } from "react";
+import { useController } from "react-hook-form";
 import { beforeEach, describe, expect, it, vi } from "vitest";
 
 const rosterGet = vi.fn();
@@ -91,6 +92,32 @@ describe("useVendorRosterForm load-error handling", () => {
     expect(result.current.selectedCompanyId).toBeNull();
   });
 
+  it("preserves entered form data when selecting an existing company fetch is rejected", async () => {
+    rosterGet.mockRejectedValueOnce(new Error("Internal server error"));
+    const { result } = renderHook(
+      () => {
+        const form = useVendorRosterForm({ mode: "create" });
+        const name = useController({ control: form.control, name: "name" });
+        return { form, name };
+      },
+      { wrapper: makeWrapper(createClient()) },
+    );
+
+    await act(async () => {
+      result.current.name.field.onChange("Draft Vendor");
+    });
+    expect(result.current.name.field.value).toBe("Draft Vendor");
+
+    await act(async () => {
+      await result.current.form.selectCompany(company);
+    });
+
+    expect(result.current.name.field.value).toBe("Draft Vendor");
+    expect(result.current.form.loadErrorMessage).toBe(
+      "Couldn't load that company's roster. Try again.",
+    );
+  });
+
   it("recovers and populates the form on retry after a rejected fetch", async () => {
     rosterGet.mockRejectedValueOnce(new Error("boom"));
     const { result } = renderHook(() => useVendorRosterForm({ mode: "create" }), {