Removed at_end; summary returns None if not available

Author: technige

examples/test_examples.py

@@ -159,7 +159,6 @@ def test_transaction_commit(self):
         result = session.run("MATCH (p:Person {name: 'Guinevere'}) RETURN count(p)")
         record = next(result)
         assert record["count(p)"] == 1
-        assert result.at_end
         session.close()
 
     def test_transaction_rollback(self):
@@ -173,7 +172,6 @@ def test_transaction_rollback(self):
         result = session.run("MATCH (p:Person {name: 'Merlin'}) RETURN count(p)")
         record = next(result)
         assert record["count(p)"] == 0
-        assert result.at_end
         session.close()
 
     def test_result_summary_query_profile(self):

neo4j/v1/exceptions.py

@@ -38,10 +38,3 @@ def __init__(self, data):
         for key, value in data.items():
             if not key.startswith("_"):
                 setattr(self, key, value)
-
-
-class ResultError(Exception):
-    """ Raised when the cursor encounters a problem.
-    """
-
-    pass

neo4j/v1/session.py

@@ -34,7 +34,7 @@ class which can be used to obtain `Driver` instances that are used for
 from .compat import integer, string, urlparse
 from .connection import connect, Response, RUN, PULL_ALL
 from .constants import ENCRYPTED_DEFAULT, TRUST_DEFAULT, TRUST_SIGNED_CERTIFICATES
-from .exceptions import CypherError, ResultError
+from .exceptions import CypherError
 from .typesystem import hydrated
 
 
@@ -198,19 +198,6 @@ def close(self):
             self._consume()
             self._connection = None
 
-    @property
-    def at_end(self):
-        """ Return ``True`` if at the end of the record stream, ``False``
-        otherwise.
-        """
-        if self._record_buffer:
-            return False
-        elif self._consumed:
-            return True
-        else:
-            self._connection.fetch()
-            return self.at_end
-
     def keys(self):
         """ Return the keys for the records.
         """
@@ -223,15 +210,14 @@ def keys(self):
     def summary(self):
         """ Return the summary from the trailing metadata. Note that this is
         only available once the entire result stream has been consumed.
-        Attempting to access the summary before then will raise an error.
+        Accessing the summary before then will return :py:const:`None`.
 
-        :rtype: ResultSummary
-        :raises ResultError: if the entire result has not yet been consumed
+        :rtype: ResultSummary or :py:const:`None`
         """
         if self._consumed:
             return self._summary
         else:
-            raise ResultError("Summary not available until the entire result has been consumed")
+            return None
 
     def _consume(self):
         # Consume the remainder of this result, triggering all appropriate callback functions.

test/test_session.py

@@ -24,7 +24,7 @@
 
 from mock import patch
 from neo4j.v1.constants import TRUST_ON_FIRST_USE
-from neo4j.v1.exceptions import CypherError, ResultError
+from neo4j.v1.exceptions import CypherError
 from neo4j.v1.session import GraphDatabase, basic_auth, Record
 from neo4j.v1.typesystem import Node, Relationship, Path
 
@@ -258,20 +258,19 @@ def test_can_obtain_summary_after_consuming_result(self):
     def test_cannot_obtain_summary_without_consuming_result(self):
         with GraphDatabase.driver("bolt://localhost", auth=auth_token).session() as session:
             result = session.run("CREATE (n) RETURN n")
-            with self.assertRaises(ResultError):
-                _ = result.summary
+            assert result.summary is None
 
     def test_no_plan_info(self):
         with GraphDatabase.driver("bolt://localhost", auth=auth_token).session() as session:
-            cursor = session.run("CREATE (n) RETURN n")
-            list(cursor)
-            assert cursor.summary.plan is None
-            assert cursor.summary.profile is None
+            result = session.run("CREATE (n) RETURN n")
+            list(result)  # consume the result
+            assert result.summary.plan is None
+            assert result.summary.profile is None
 
     def test_can_obtain_plan_info(self):
         with GraphDatabase.driver("bolt://localhost", auth=auth_token).session() as session:
             result = session.run("EXPLAIN CREATE (n) RETURN n")
-            list(result)
+            list(result)  # consume the result
             plan = result.summary.plan
             assert plan.operator_type == "ProduceResults"
             assert plan.identifiers == ["n"]
@@ -283,7 +282,7 @@ def test_can_obtain_plan_info(self):
     def test_can_obtain_profile_info(self):
         with GraphDatabase.driver("bolt://localhost", auth=auth_token).session() as session:
             result = session.run("PROFILE CREATE (n) RETURN n")
-            list(result)
+            list(result)  # consume the result
             profile = result.summary.profile
             assert profile.db_hits == 0
             assert profile.rows == 1
@@ -297,14 +296,14 @@ def test_can_obtain_profile_info(self):
     def test_no_notification_info(self):
         with GraphDatabase.driver("bolt://localhost", auth=auth_token).session() as session:
             result = session.run("CREATE (n) RETURN n")
-            list(result)
+            list(result)  # consume the result
             notifications = result.summary.notifications
             assert notifications == []
 
     def test_can_obtain_notification_info(self):
         with GraphDatabase.driver("bolt://localhost", auth=auth_token).session() as session:
             result = session.run("EXPLAIN MATCH (n), (m) RETURN n, m")
-            list(result)
+            list(result)  # consume the result
             notifications = result.summary.notifications
 
             assert len(notifications) == 1