added test for case where no status

src/registrar/admin.py

@@ -267,11 +267,13 @@ class DomainApplicationAdminForm(forms.ModelForm):
         instance = kwargs.get("instance")
         if instance and instance.pk:
             current_state = instance.status
+
+            # first option in status transitions is current state
+            available_transitions = [(current_state, current_state)]
+
             transitions = get_available_FIELD_transitions(
                 instance, models.DomainApplication._meta.get_field("status")
             )
-            # first option in status transitions is current state
-            available_transitions = [(current_state, current_state)]
 
             for transition in transitions:
                 available_transitions.append((transition.target, transition.target))

src/registrar/tests/test_admin.py

@@ -106,6 +106,20 @@ class TestDomainApplicationAdminForm(TestCase):
         expected_choices = [("started", "started"), ("submitted", "submitted")]
         self.assertEqual(form.fields["status"].widget.choices, expected_choices)
 
+    def test_form_choices_when_no_instance(self):
+        # Create a form instance without an instance
+        form = DomainApplicationAdminForm()
+
+        # Verify that the form choices show all choices when no instance is provided;
+        # this is necessary to show all choices when creating a new domain
+        # application in django admin;
+        # note that FSM ensures that no domain application exists with invalid status,
+        # so don't need to test for invalid status
+        self.assertEqual(
+            form.fields["status"].widget.choices,
+            DomainApplication._meta.get_field("status").choices,
+        )
+
 
 class TestDomainApplicationAdmin(TestCase):
     def setUp(self):