🐛 support/fixed signal when using @transaction because of session.beg…

…in_nested

docs/changelog.rst

@@ -1,6 +1,11 @@
 Change history
 ==============
 
+2.2.3 (2022-05-18)
+******************
+
+* Support use nested=None(`@transaction(db.session, nested=None)`) to avoid bug from `flask_sqlalchemy.models_committed` signal.
+
 2.2.2 (2022-02-17)
 ******************
 

hobbit_core/db.py

@@ -312,6 +312,9 @@ def transaction(session: Session, nested: bool = False):
     or ``session.autocommit=True``.
     See more: http://flask-sqlalchemy.pocoo.org/2.3/api/#sessions
 
+    2022-05-18 Updated: Use `nested=None` to prevent signal bug, See more:
+    https://github.com/pallets-eco/flask-sqlalchemy/issues/645
+
     Tips:
         * **Can't** do ``session.commit()`` **in func**, **otherwise raise**
           ``sqlalchemy.exc.ResourceClosedError``: `This transaction is closed`.
@@ -361,8 +364,11 @@ def inner(*args, **kwargs):
             if session.autocommit is True and nested is False:
                 session.begin()  # start a transaction
             try:
-                with session.begin_nested():
+                if nested is None:
                     resp = func(*args, **kwargs)
+                else:
+                    with session.begin_nested():
+                        resp = func(*args, **kwargs)
                 if not nested:
                     # commit - begin(), transaction finished
                     session.commit()

setup.py

@@ -32,7 +32,7 @@ def gen_data(data_root='static'):
 
 setup(
     name='hobbit-core',
-    version='2.2.2',
+    version='2.2.3',
     python_requires='>=3.6, <4',
     description='Hobbit - A flask project generator.',
     long_description=long_description,

tests/test_app/models.py

@@ -1,5 +1,6 @@
 # -*- encoding: utf-8 -*-
 from sqlalchemy import UniqueConstraint, func, DateTime, BigInteger
+from flask_sqlalchemy import models_committed
 
 from hobbit_core.db import Column, BaseModel, EnumExt
 
@@ -18,6 +19,22 @@ class User(BaseModel):
     role = Column(db.Enum(RoleEnum), doc='角色', default=RoleEnum.admin)
 
 
+@models_committed.connect
+def signalling(app, changes, **kwargs):
+    for instance, operation in changes:
+        if instance.__tablename__ in [i.__tablename__ for i in [User]]:
+            models_committed.disconnect(signalling)
+            session = db.create_scoped_session()
+            user = session.query(User).first()
+            if user and user.username == 'signalling_test':
+                user.username = 'signalling_ok'
+                session.merge(user)
+                session.commit()
+            session.remove()
+            models_committed.connect(signalling)
+            break
+
+
 class Role(BaseModel):  # just for assert multi model worked
     name = Column(db.String(50), nullable=False, unique=True)
 

tests/test_app/run.py

@@ -15,7 +15,7 @@ class ConfigClass:
         'oracle': 'oracle://scott:tiger@localhost/test',
         'mysql': 'mysql+pymysql://root:root@localhost/hobbit_core',
     }
-    SQLALCHEMY_TRACK_MODIFICATIONS = False
+    SQLALCHEMY_TRACK_MODIFICATIONS = True
     # SQLALCHEMY_ECHO = True
     TESTING = True
 

tests/test_app/views.py

@@ -4,8 +4,11 @@
 from webargs.flaskparser import use_kwargs as base_use_kwargs
 
 from hobbit_core.utils import use_kwargs
+from hobbit_core.db import transaction
 
 from .schemas import UserSchema
+from .exts import db
+from .models import User
 
 bp = Blueprint('test', __name__)
 
@@ -48,3 +51,27 @@ def use_kwargs_dictargmap_partial(**kwargs):
 })
 def base_use_kwargs_dictargmap_partial(**kwargs):
     return jsonify(wrapper_kwargs(kwargs))
+
+
+@bp.route('/create_user/success/', methods=['POST'])
+@base_use_kwargs({'email': fields.Str()})
+def create_user_success(email):
+    @transaction(db.session, nested=None)
+    def create_user():
+        user1 = User(username='signalling_test', email=email, password='1')
+        db.session.add(user1)
+
+    create_user()
+    return jsonify({})
+
+
+@bp.route('/create_user/failed/', methods=['POST'])
+@base_use_kwargs({'email': fields.Str()})
+def create_user_failed(email):
+    @transaction(db.session)
+    def create_user():
+        user1 = User(username='signalling_test', email=email, password='1')
+        db.session.add(user1)
+
+    create_user()
+    return jsonify({})

tests/test_db.py

@@ -301,3 +301,22 @@ def test_autocommittrue_not_excepted(self, auto_session, assert_session):
 
         # assert not rollback. Be very careful when using commit. 😒😒😒😒
         assert len(assert_session.query(User).all()) == 1
+
+
+class TestNestedSessionSignal(BaseTest):
+
+    def test_transaction_signal_success(self, client, assert_session):
+        email = "[email protected]"
+        resp = client.post('/create_user/success/', json={"email": email})
+        assert resp.status_code == 200
+
+        user = assert_session.query(User).filter(User.email == email).first()
+        assert user and user.username == "signalling_ok"
+
+    def test_transaction_signal_dailed(self, client, assert_session):
+        email = "[email protected]"
+        resp = client.post('/create_user/failed/', json={"email": email})
+        assert resp.status_code == 200
+
+        user = assert_session.query(User).filter(User.email == email).first()
+        assert user and user.username != "signalling_ok"