Fix ResourceWarning: unclosed database in SqliteReader and unit tests

- SqliteReader was missing a close() method
- sqlite3.Connection as a context manager does NOT close the connection
it only commits or rolls back the transaction.

Author: yunzheng

flow/record/adapter/sqlite.py

@@ -204,6 +204,11 @@ def __iter__(self) -> Iterator[Record]:
                 if match_record_with_context(record, selector, ctx):
                     yield record
 
+    def close(self) -> None:
+        if self.con:
+            self.con.close()
+        self.con = None
+
 
 class SqliteWriter(AbstractWriter):
     """SQLite writer."""

tests/adapter/test_sqlite_duckdb.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import sqlite3
+from contextlib import closing
 from datetime import datetime, timezone
 from typing import TYPE_CHECKING, Any, NamedTuple
 
@@ -136,7 +137,7 @@ def test_write_to_sqlite(tmp_path: Path, count: int, db: Database) -> None:
             writer.write(record)
 
     record_count = 0
-    with db.connector.connect(str(db_path)) as con:
+    with closing(db.connector.connect(str(db_path))) as con:
         cursor = con.execute("SELECT COUNT(*) FROM 'test/record'")
         record_count = cursor.fetchone()[0]
 
@@ -157,7 +158,7 @@ def test_read_from_sqlite(tmp_path: Path, db: Database) -> None:
     """Tests basic reading from a SQLite database."""
     # Generate a SQLite database
     db_path = tmp_path / "records.db"
-    with db.connector.connect(str(db_path)) as con:
+    with closing(db.connector.connect(str(db_path))) as con:
         con.execute(
             """
             CREATE TABLE 'test/record' (
@@ -176,6 +177,7 @@ def test_read_from_sqlite(tmp_path: Path, db: Database) -> None:
                 """,
                 (f"record{i}", f"foobar{i}".encode(), dt_isoformat, 3.14 + i),
             )
+        con.commit()
 
     # Read the SQLite database using flow.record
     with RecordReader(f"{db.scheme}://{db_path}") as reader:
@@ -251,7 +253,7 @@ def test_write_zero_records(tmp_path: Path, db: Database) -> None:
         assert writer
 
     # test if it's a valid database
-    with db.connector.connect(str(db_path)) as con:
+    with closing(db.connector.connect(str(db_path))) as con:
         assert con.execute("SELECT * FROM sqlite_master").fetchall() == []
 
 
@@ -272,9 +274,10 @@ def test_write_zero_records(tmp_path: Path, db: Database) -> None:
 def test_non_strict_sqlite_fields(tmp_path: Path, sqlite_coltype: str, sqlite_value: Any, expected_value: Any) -> None:
     """SQLite by default is non strict, meaning that the value could be of different type than the column type."""
     db = tmp_path / "records.db"
-    with sqlite3.connect(db) as con:
+    with closing(sqlite3.connect(db)) as con:
         con.execute(f"CREATE TABLE 'strict-test' (field {sqlite_coltype})")
         con.execute("INSERT INTO 'strict-test' VALUES(?)", (sqlite_value,))
+        con.commit()
 
     with RecordReader(f"sqlite://{db}") as reader:
         record = next(iter(reader))
@@ -294,10 +297,11 @@ def test_invalid_table_names_quoting(tmp_path: Path, invalid_table_name: str) ->
 
     # Creating the tables with these invalid_table_names in SQLite is no problem
     db = tmp_path / "records.db"
-    with sqlite3.connect(db) as con:
+    with closing(sqlite3.connect(db)) as con:
         con.execute(f"CREATE TABLE [{invalid_table_name}] (field TEXT, field2 TEXT)")
         con.execute(f"INSERT INTO [{invalid_table_name}] VALUES(?, ?)", ("hello", "world"))
         con.execute(f"INSERT INTO [{invalid_table_name}] VALUES(?, ?)", ("goodbye", "planet"))
+        con.commit()
 
     # However, these invalid_table_names should raise an exception when reading
     with (
@@ -320,10 +324,11 @@ def test_invalid_field_names_quoting(tmp_path: Path, invalid_field_name: str) ->
 
     # Creating the table with invalid field name in SQLite is no problem
     db = tmp_path / "records.db"
-    with sqlite3.connect(db) as con:
+    with closing(sqlite3.connect(db)) as con:
         con.execute(f"CREATE TABLE [test] (field TEXT, [{invalid_field_name}] TEXT)")
         con.execute("INSERT INTO [test] VALUES(?, ?)", ("hello", "world"))
         con.execute("INSERT INTO [test] VALUES(?, ?)", ("goodbye", "planet"))
+        con.commit()
 
     # However, these field names are invalid in flow.record and should raise an exception
     with (
@@ -365,7 +370,7 @@ def test_batch_size(
         writer.write(next(records))
 
         # test count of records in table (no flush yet if batch_size > 1)
-        with db.connector.connect(str(db_path)) as con:
+        with closing(db.connector.connect(str(db_path))) as con:
             x = con.execute('SELECT COUNT(*) FROM "test/record"')
             assert x.fetchone()[0] is expected_first
 
@@ -374,7 +379,7 @@ def test_batch_size(
             writer.write(next(records))
 
         # test count of records in table after flush
-        with db.connector.connect(str(db_path)) as con:
+        with closing(db.connector.connect(str(db_path))) as con:
             x = con.execute('SELECT COUNT(*) FROM "test/record"')
             assert x.fetchone()[0] == expected_second