Add before_insert decorator shortcut

src/sqlalchemy_events.py

@@ -44,3 +44,13 @@ def wrapper(fn):
         return fn
 
     return wrapper
+
+
+def before_insert(*args):
+    def wrapper(fn):
+        setattr(fn, _EventObject.ATTR, _EventObject(None, "before_insert"))
+        return fn
+
+    if args and callable(args[0]):
+        return wrapper(args[0])
+    return wrapper

tests/orm/mapper_event_test.py

@@ -3,7 +3,7 @@
 from sqlalchemy.orm import sessionmaker
 from sqlalchemy import Column, Integer, String
 from sqlalchemy.ext.declarative import declarative_base
-from src.sqlalchemy_events import listen_events, on
+from src.sqlalchemy_events import listen_events, on, before_insert
 
 Base = declarative_base()
 
@@ -28,7 +28,7 @@ def setup_database():
     session.close()
 
 
-def test_before_commit(setup_database):
+def test_before_insert(setup_database):
     @listen_events
     class User(BaseModel):
         @on("before_insert")
@@ -47,3 +47,20 @@ def lowercase_username(mapper, conn, self):
     mary = session.query(User).filter(User.username == "mary").first()
     assert john.username == "john"
     assert mary.username == "mary"
+
+
+def test_before_insert_decorator(setup_database):
+    @listen_events
+    class User(BaseModel):
+        @before_insert
+        def lowercase_username(mapper, conn, self):
+            self.username = self.username.lower()
+
+    session = setup_database
+    user_1 = User(username="John")
+
+    session.add(user_1)
+    session.commit()
+
+    john = session.query(User).filter(User.username == "john").first()
+    assert john.username == "john"