[tests] Validate missing body return code in registration

tests/unit/test_api_register.py

@@ -0,0 +1,15 @@
+from fastapi import FastAPI, status
+from fastapi.testclient import TestClient
+from kibicara.model import Mapping
+from kibicara.webapi import router
+
+
+app = FastAPI()
+app.include_router(router, prefix='/api')
+client = TestClient(app)
+Mapping.create_all()
+
+
+def test_register_missing_body():
+    response = client.post('/api/admin/register/')
+    assert response.status_code == status.HTTP_422_UNPROCESSABLE_ENTITY