fix: show short, accurate placeholders with a tooltip on the admin branding fields of a domain

app/(main)/admin/__tests__/branding-placeholders.test.tsx

@@ -0,0 +1,37 @@
+import { fireEvent, render, screen } from '@testing-library/react';
+import { afterEach, describe, expect, it, vi } from 'vitest';
+import { useAdminUnsavedStore } from '@/stores/admin-unsaved-store';
+
+// Branding per domain: the image fields said "Enter URL (uploads only for
+// default scope)", cut off in the field and wrong for a single domain, which
+// can upload. Only a wildcard domain takes a URL alone.
+
+vi.mock('@/lib/browser-navigation', () => ({
+  apiFetch: vi.fn(async () => new Response(JSON.stringify({
+    domainBranding: { source: 'admin', value: [{ host: 'mail.example.com' }, { host: '*.example.com' }] },
+  }), { status: 200, headers: { 'content-type': 'application/json' } })),
+  withBasePath: (p: string) => p,
+}));
+vi.mock('next/link', () => ({ default: ({ children }: { children: React.ReactNode }) => children }));
+
+import { BrandingPage } from '../_pages/branding';
+
+afterEach(() => {
+  useAdminUnsavedStore.setState({ dirty: {}, pendingLeave: null, pendingScope: null });
+});
+
+describe('admin branding image fields', () => {
+  it('offers upload for a single domain and a URL only for a wildcard, with the full hint as a title', async () => {
+    render(<BrandingPage />);
+
+    fireEvent.click(await screen.findByRole('button', { name: 'mail.example.com' }));
+    const favicon = screen.getByRole('textbox', { name: 'Favicon' });
+    expect(favicon.getAttribute('placeholder')).toBe('Enter URL or upload a file');
+    expect(favicon.getAttribute('title')).toBe('Enter URL or upload a file');
+
+    fireEvent.click(screen.getByRole('button', { name: '*.example.com' }));
+    const wildcardFavicon = screen.getByRole('textbox', { name: 'Favicon' });
+    expect(wildcardFavicon.getAttribute('placeholder')).toBe('Enter URL');
+    expect(wildcardFavicon.getAttribute('title')).toBe('Enter URL');
+  });
+});

app/(main)/admin/_pages/branding.tsx

@@ -396,7 +396,9 @@ export function BrandingPage() {
       accept={field.accept}
       value={currentValue(field.key)}
       badge={overrideBadge(field.key)}
-      placeholder={selectedHost ? 'Enter URL (uploads only for default scope)' : 'Enter URL or upload a file'}
+      // Files upload to the default scope and to exact hosts; a wildcard has
+      // no single host to serve them from (the scope line says so).
+      placeholder={wildcardScope ? 'Enter URL' : 'Enter URL or upload a file'}
       uploading={uploading === field.key}
       uploadDisabled={wildcardScope}
       uploaded={isUploadedFile(field.key)}
@@ -417,6 +419,7 @@ export function BrandingPage() {
           value={currentValue(field.key)}
           onChange={(e) => handleChange(field.key, e.target.value)}
           placeholder={placeholder}
+          title={placeholder}
           aria-label={field.label}
           autoComplete="off"
           spellCheck={false}
@@ -592,6 +595,7 @@ function ImageItem({ label, accept, value, badge, placeholder, uploading, upload
             value={value}
             onChange={(e) => onChange(e.target.value)}
             placeholder={placeholder}
+            title={placeholder}
             aria-label={label}
             autoComplete="off"
             spellCheck={false}