Fix SesstionTransaction._connection_for_bind call. Fixes #53

pytest_flask_sqlalchemy/fixtures.py

@@ -1,5 +1,5 @@
-import os
 import contextlib
+import os
 
 import pytest
 import sqlalchemy as sa
@@ -144,6 +144,12 @@ def raw_connection():
 
     engine.raw_connection = raw_connection
 
+    # Fix SessionTransaction._connection_for_bind caching
+    @sa.event.listens_for(session, 'after_begin')
+    def after_begin(session, transaction, conn):
+        if engine not in transaction._connections:
+            transaction._connections[engine] = transaction._connections[conn]
+
     for mocked_engine in pytestconfig._mocked_engines:
         mocker.patch(mocked_engine, new=engine)
 

tests/test_fixtures.py

@@ -336,3 +336,32 @@ def test_delete_message(account_address, db_session):
 
     result = db_testdir.runpytest()
     result.assert_outcomes(passed=1)
+
+
+def test_rollback_nested(db_testdir):
+    '''
+    Test that creating objects and emitting SQL in the ORM won't bleed into
+    other tests.
+    '''
+    # Load tests from file
+    db_testdir.makepyfile("""
+        def test_rollback_nested(person, db_session, caplog):
+            assert db_session.query(person).count() == 0
+            n1 = db_session.begin_nested()
+            db_session.add(person())
+            assert db_session.query(person).count() == 1
+
+            n2 = db_session.begin_nested()
+            db_session.add(person())
+            assert db_session.query(person).count() == 2
+
+            n2.rollback()
+            print(db_session.bind.mock_calls)
+            assert db_session.query(person).count() == 1
+            n1.rollback()
+            assert db_session.query(person).count() == 0
+    """)
+
+    # Run tests
+    result = db_testdir.runpytest()
+    result.assert_outcomes(passed=1)