See #432: enforce a maximum number of tags per entity

api/tests/tags/test_models.py

@@ -53,6 +53,24 @@ def test_set_tags(factories, existing, given, expected):
         assert match.content_object == obj
 
 
+@pytest.mark.parametrize(
+    "max, tags, expected",
+    [
+        (5, ["hello", "world"], ["hello", "world"]),
+        # we truncate extra tags
+        (1, ["hello", "world"], ["hello"]),
+        (2, ["hello", "world", "foo"], ["hello", "world"]),
+    ],
+)
+def test_set_tags_honor_TAGS_MAX_BY_OBJ(factories, max, tags, expected, settings):
+    settings.TAGS_MAX_BY_OBJ = max
+    obj = factories["music.Artist"]()
+
+    models.set_tags(obj, *tags)
+
+    assert sorted(obj.tagged_items.values_list("tag__name", flat=True)) == expected
+
+
 @pytest.mark.parametrize("factory_name", ["music.Track", "music.Album", "music.Artist"])
 def test_models_that_support_tags(factories, factory_name):
     tags = ["tag1", "tag2"]

api/tests/tags/test_serializers.py

@@ -29,3 +29,18 @@ def test_tag_name_field_validation(name):
     field = serializers.TagNameField()
     with pytest.raises(serializers.serializers.ValidationError):
         field.to_internal_value(name)
+
+
+@pytest.mark.parametrize(
+    "max, tags, expected",
+    [
+        (5, ["hello", "world"], ["hello", "world"]),
+        # we truncate extra tags
+        (1, ["hello", "world"], ["hello"]),
+        (2, ["hello", "world", "foo"], ["hello", "world"]),
+    ],
+)
+def test_tags_list_field_honor_TAGS_MAX_BY_OBJ(max, tags, expected, settings):
+    settings.TAGS_MAX_BY_OBJ = max
+    field = serializers.TagsListField()
+    assert field.to_internal_value(tags) == expected