add name_parts_is_empty helper

src/tests/base/test_questions.py

@@ -0,0 +1,11 @@
+from pretix.base.forms.questions import name_parts_is_empty
+
+
+def test_name_parts_is_empty():
+    assert name_parts_is_empty({}) is True
+    assert name_parts_is_empty({"_scheme": "foo"}) is True
+    assert name_parts_is_empty({"_scheme": "foo", "full_name": ""}) is True
+    assert name_parts_is_empty({"full_name": None}) is True
+    assert name_parts_is_empty({"full_name": "Flora Nord"}) is False
+    assert name_parts_is_empty({"_scheme": "foo", "given_name": "Alice"}) is False
+    assert name_parts_is_empty({"_legacy": "Alice"}) is False