fix architecture and write new tests

apps/admin/src/app/favicon.ico/route.test.ts

@@ -0,0 +1,30 @@
+import { describe, expect, it, vi } from 'vitest'
+
+const nextServer = vi.hoisted(() => ({
+  redirect: vi.fn((url: URL) => ({ kind: 'redirect', url: url.toString() })),
+}))
+
+vi.mock('next/server', () => ({
+  NextResponse: {
+    redirect: nextServer.redirect,
+  },
+}))
+
+describe('admin favicon route', () => {
+  it('redirects favicon requests to the generated icon route on the same origin', async () => {
+    const { GET } = await import('./route')
+
+    const response = GET(new Request('https://admin.example.com/favicon.ico'))
+
+    expect(response).toEqual({ kind: 'redirect', url: 'https://admin.example.com/icon' })
+    expect(nextServer.redirect).toHaveBeenCalledTimes(1)
+  })
+
+  it('preserves forwarded path base through the request URL origin only', async () => {
+    const { GET } = await import('./route')
+
+    const response = GET(new Request('https://admin.example.com/admin/favicon.ico'))
+
+    expect(response).toEqual({ kind: 'redirect', url: 'https://admin.example.com/icon' })
+  })
+})