Add a test about selection score for jsonschema.item mappers for relations

test/test_mappers.py

@@ -34,6 +34,7 @@ from cubicweb.predicates import match_kwargs
 from cubicweb_jsonschema import CREATION_ROLE, EDITION_ROLE, VIEW_ROLE
 from cubicweb_jsonschema.mappers import (
     JSONSchemaDeserializer,
+    JSONSchemaMapper,
     JSONSchemaSerializer,
     CompoundMapper,
     yams_component_target,
@@ -394,6 +395,45 @@ class RelatedCollectionMapperTC(CubicWebTC):
         self.assertEqual(instance, expected)
         assert_jsonschema_validate(instance, schema)
 
+    def test_custom_mapper(self):
+        """Make sure a custom mapper with a yams_match selector wins selection
+        over default one.
+        """
+
+        class reverse_author_mapper(JSONSchemaMapper):
+            __regid__ = 'jsonschema.item'
+            __select__ = yams_match(rtype='author', role='object')
+
+            def schema_and_definitions(self, schema_role=None):
+                return {
+                    'type': 'object',
+                    'properties': {
+                        'name': {'type': 'string'},
+                    },
+                }, None
+
+            def serialize(self, entity):
+                return {
+                    'name': entity.name,
+                }
+
+        with self.admin_access.cnx() as cnx:
+            author = cnx.create_entity('Author', name=u'bob')
+            cnx.commit()
+            with self.temporary_appobjects(reverse_author_mapper):
+                item_mapper = cnx.vreg['mappers'].select(
+                    'jsonschema.item', cnx, entity=author,
+                    rtype='author', role='object')
+                collection_mapper = cnx.vreg['mappers'].select(
+                    'jsonschema.collection', cnx, etype='Author',
+                    rtype='author', role='object')
+                self.assertIsInstance(item_mapper, reverse_author_mapper)
+                self.assertEqual(item_mapper.serialize(author),
+                                 {'name': 'bob'})
+                authors = collection_mapper.serialize([author])
+                self.assertEqual(authors,
+                                 [{'name': 'bob'}])
+
 
 class RelationMapperTC(CubicWebTC):