test: SearchableField.has_changed() should handle non-list initial val

ietf/utils/tests.py

@@ -25,6 +25,7 @@
 from django.apps import apps
 from django.contrib.auth.models import User
 from django.conf import settings
+from django.forms import Form
 from django.template import Context
 from django.template import Template    # pyflakes:ignore
 from django.template.defaulttags import URLNode
@@ -37,6 +38,7 @@
 from ietf.person.name import name_parts, unidecode_name
 from ietf.submit.tests import submission_file
 from ietf.utils.draft import PlaintextDraft, getmeta
+from ietf.utils.fields import SearchableField
 from ietf.utils.log import unreachable, assertion
 from ietf.utils.mail import send_mail_preformatted, send_mail_text, send_mail_mime, outbox, get_payload_text
 from ietf.utils.test_runner import get_template_paths, set_coverage_checking
@@ -517,3 +519,25 @@ def test_timezone_not_near_midnight(self, mock):
         ):
             with self.assertRaises(RuntimeError):
                 timezone_not_near_midnight()
+
+
+class SearchableFieldTests(TestCase):
+    def test_has_changed_single_value(self):
+        """Should work with initial as a single value or list when max_entries == 1"""
+        class TestSearchableField(SearchableField):
+            model = "fake model"  # needs to be not-None to allow field init
+
+        class TestForm(Form):
+            test_field = TestSearchableField(max_entries=1)
+
+        # single value in initial (e.g., when used as a single-valued field in a formset)
+        changed_form = TestForm(initial={'test_field': 1}, data={'test_field': [2]})
+        self.assertTrue(changed_form.has_changed())
+        unchanged_form = TestForm(initial={'test_field': 1}, data={'test_field': [1]})
+        self.assertFalse(unchanged_form.has_changed())
+
+        # list value in initial (usual situation for a MultipleChoiceField subclass like SearchableField)
+        changed_form = TestForm(initial={'test_field': [1]}, data={'test_field': [2]})
+        self.assertTrue(changed_form.has_changed())
+        unchanged_form = TestForm(initial={'test_field': [1]}, data={'test_field': [1]})
+        self.assertFalse(unchanged_form.has_changed())