Merge pull request #13924 from edx/adam/neo4j-lists

only pass lists of text as iterable neo4j values

openedx/core/djangoapps/coursegraph/management/commands/dump_to_neo4j.py

@@ -27,7 +27,6 @@ log = logging.getLogger(__name__)
 bolt_log = logging.getLogger('neo4j.bolt')  # pylint: disable=invalid-name
 bolt_log.setLevel(logging.ERROR)
 
-ITERABLE_NEO4J_TYPES = (tuple, list, set, frozenset)
 PRIMITIVE_NEO4J_TYPES = (integer, string, neo4j_unicode, float, bool)
 
 COMMAND_LAST_RUN_CACHE = CommandLastRunCache()
@@ -140,16 +139,11 @@ class ModuleStoreSerializer(object):
             value: the value of an xblock's field
 
         Returns: either the value, a text version of the value, or, if the
-        value is iterable, the value with each element being converted to text
+        value is a list, a list where each element is converted to text.
         """
-
         coerced_value = value
-        if isinstance(value, ITERABLE_NEO4J_TYPES):
-            coerced_value = []
-            for element in value:
-                coerced_value.append(six.text_type(element))
-            # convert coerced_value back to its original type
-            coerced_value = type(value)(coerced_value)
+        if isinstance(value, list):
+            coerced_value = [six.text_type(element) for element in coerced_value]
 
         # if it's not one of the types that neo4j accepts,
         # just convert it to text

openedx/core/djangoapps/coursegraph/management/commands/tests/test_dump_to_neo4j.py

@@ -15,7 +15,6 @@ from xmodule.modulestore.tests.factories import CourseFactory, ItemFactory
 
 from openedx.core.djangoapps.coursegraph.management.commands.dump_to_neo4j import (
     ModuleStoreSerializer,
-    ITERABLE_NEO4J_TYPES,
 )
 from openedx.core.djangoapps.coursegraph.signals import _listen_for_course_publish
 
@@ -131,21 +130,6 @@ class TestModuleStoreSerializer(TestDumpToNeo4jCommandBase):
         self.assertEqual(len(nodes), 9)
         self.assertEqual(len(relationships), 7)
 
-    @ddt.data(*ITERABLE_NEO4J_TYPES)
-    def test_coerce_types_iterable(self, iterable_type):
-        """
-        Tests the coerce_types helper method for iterable types
-        """
-        example_iterable = iterable_type([object, object, object])
-
-        # each element in the iterable is not unicode:
-        self.assertFalse(any(isinstance(tab, six.text_type) for tab in example_iterable))
-        # but after they are coerced, they are:
-        coerced = ModuleStoreSerializer().coerce_types(example_iterable)
-        self.assertTrue(all(isinstance(tab, six.text_type) for tab in coerced))
-        # finally, make sure we haven't changed the type:
-        self.assertEqual(type(coerced), iterable_type)
-
     @ddt.data(
         (1, 1),
         (object, "<type 'object'>"),
@@ -154,11 +138,15 @@ class TestModuleStoreSerializer(TestDumpToNeo4jCommandBase):
         (b"plain string", b"plain string"),
         (True, True),
         (None, "None"),
+        ((1,), "(1,)"),
+        # list of elements should be coerced into a list of the
+        # string representations of those elements
+        ([object, object], ["<type 'object'>", "<type 'object'>"])
     )
     @ddt.unpack
-    def test_coerce_types_base(self, original_value, coerced_expected):
+    def test_coerce_types(self, original_value, coerced_expected):
         """
-        Tests the coerce_types helper for the neo4j base types
+        Tests the coerce_types helper
         """
         coerced_value = self.mss.coerce_types(original_value)
         self.assertEqual(coerced_value, coerced_expected)