Add clean method to ensure mixed static segments are valid

tests/unit/test_static_dynamic_segments.py

@@ -4,6 +4,7 @@ import datetime
 
 import pytest
 
+from django.core.exceptions import ValidationError
 from tests.factories.segment import SegmentFactory
 from wagtail_personalisation.models import Segment
 from wagtail_personalisation.rules import TimeRule, VisitCountRule
@@ -116,3 +117,39 @@ def test_does_not_calculate_the_segment_again(rf, site, client, mocker):
     mock_test_rule = mocker.patch('wagtail_personalisation.adapters.SessionSegmentsAdapter._test_rules')
     client.get(site.root_page.url)
     assert mock_test_rule.call_count == 0
+
+
+@pytest.mark.django_db
+def test_non_static_rules_have_a_count():
+    segment = SegmentFactory(type=Segment.TYPE_STATIC, count=0)
+    TimeRule.objects.create(
+        start_time=datetime.time(0, 0, 0),
+        end_time=datetime.time(23, 59, 59),
+        segment=segment,
+    )
+    with pytest.raises(ValidationError):
+        segment.clean()
+
+
+@pytest.mark.django_db
+def test_static_segment_with_static_rules_needs_no_count(site):
+    segment = SegmentFactory(type=Segment.TYPE_STATIC, count=0)
+    VisitCountRule.objects.create(counted_page=site.root_page, segment=segment)
+    try:
+        segment.clean()
+    except ValidationError:
+        pytest.fail('Should not raise ValidationError.')
+
+
+@pytest.mark.django_db
+def test_dynamic_segment_with_non_static_rules_have_a_count():
+    segment = SegmentFactory(type=Segment.TYPE_DYNAMIC, count=0)
+    TimeRule.objects.create(
+        start_time=datetime.time(0, 0, 0),
+        end_time=datetime.time(23, 59, 59),
+        segment=segment,
+    )
+    try:
+        segment.clean()
+    except ValidationError:
+        pytest.fail('Should not raise ValidationError.')