Implement Connection.isolation_level

Author: penberg

docs/api.md

@@ -123,15 +123,15 @@ Unimplemented.
 
 ### autocommit
 
-Unimplemented.
+The driver only supports the legacy `isolation_level`-based transaction mode control and does not implement the `autocommit` property yet (see issue [#30](https://github.com/libsql/libsql-experimental-python/issues/30) for details).
 
 ### in_transaction
 
 Returns `True` if there's an active transaction with uncommitted changes; otherwise returns `False`.
 
 ### isolation_level
 
-Unimplemented.
+Transaction handling mode configuration. If `isolation_level` is set to `"DEFERRED"`, `"IMMEDIATE"`, or `"EXCLUSIVE"`, transactions begin implicitly, but need to be committed manually. If `isolation_level` is set to `None`, then database is in auto-commit mode, executing each statement in its own transaction.
 
 ### row_factory
 

src/lib.rs

@@ -19,10 +19,10 @@ fn is_remote_path(path: &str) -> bool {
 }
 
 #[pyfunction]
-#[pyo3(signature = (database, isolation_level="DEFERRED", check_same_thread=true, uri=false, sync_url=None, auth_token=""))]
+#[pyo3(signature = (database, isolation_level="DEFERRED".to_string(), check_same_thread=true, uri=false, sync_url=None, auth_token=""))]
 fn connect(
     database: String,
-    isolation_level: Option<&str>,
+    isolation_level: Option<String>,
     check_same_thread: bool,
     uri: bool,
     sync_url: Option<String>,
@@ -56,6 +56,7 @@ fn connect(
         db,
         conn,
         rt,
+        isolation_level,
         autocommit,
     })
 }
@@ -65,6 +66,7 @@ pub struct Connection {
     db: libsql_core::Database,
     conn: Arc<libsql_core::Connection>,
     rt: tokio::runtime::Runtime,
+    isolation_level: Option<String>,
     autocommit: bool,
 }
 
@@ -139,6 +141,11 @@ impl Connection {
         Ok(cursor)
     }
 
+    #[getter]
+    fn isolation_level(self_: PyRef<'_, Self>) -> Option<String> {
+        self_.isolation_level.clone()
+    }
+
     #[getter]
     fn in_transaction(self_: PyRef<'_, Self>) -> PyResult<bool> {
         Ok(!self_.conn.is_autocommit())

tests/test_suite.py

@@ -116,6 +116,7 @@ def test_commit_and_rollback(provider):
 @pytest.mark.parametrize("provider", ["libsql", "sqlite"])
 def test_autocommit(provider):
     conn = connect(provider, ":memory:", None)
+    assert conn.isolation_level == None
     assert conn.in_transaction == False
     cur = conn.cursor()
     assert conn.in_transaction == False