feat: support commit and rollback on connection

resolves #6

fakesnow/fakes.py

@@ -396,6 +396,9 @@ def __exit__(
     ) -> bool:
         return False
 
+    def commit(self) -> None:
+        self.cursor().execute("COMMIT")
+
     def cursor(self, cursor_class: Type[SnowflakeCursor] = SnowflakeCursor) -> FakeSnowflakeCursor:
         return FakeSnowflakeCursor(conn=self, duck_conn=self._duck_conn, use_dict_result=cursor_class == DictCursor)
 
@@ -414,6 +417,9 @@ def execute_string(
         ]
         return cursors if return_cursors else []
 
+    def rollback(self) -> None:
+        self.cursor().execute("ROLLBACK")
+
     def _insert_df(
         self, df: pd.DataFrame, table_name: str, database: str | None = None, schema: str | None = None
     ) -> int:

tests/test_fakes.py

@@ -462,6 +462,23 @@ def test_timestamp_to_date(cur: snowflake.connector.cursor.SnowflakeCursor):
     assert cur.fetchall() == [(datetime.date(1970, 1, 1), datetime.date(1970, 1, 1))]
 
 
+def test_transactions(conn: snowflake.connector.SnowflakeConnection):
+    conn.execute_string(
+        """CREATE TABLE table1 (i int);
+            BEGIN TRANSACTION;
+            INSERT INTO table1 (i) VALUES (1);"""
+    )
+    conn.rollback()
+    conn.execute_string(
+        """BEGIN TRANSACTION;
+            INSERT INTO table1 (i) VALUES (2);"""
+    )
+    conn.commit()
+    with conn.cursor() as cur:
+        cur.execute("SELECT * FROM table1")
+        assert cur.fetchall() == [(2,)]
+
+
 def test_unquoted_identifiers_are_upper_cased(conn: snowflake.connector.SnowflakeConnection):
     with conn.cursor(snowflake.connector.cursor.DictCursor) as cur:
         cur.execute("create table customers (id int, first_name varchar, last_name varchar)")