Close write connection after read connections.

Author: rkistner

lib/src/connection_pool.dart

@@ -174,9 +174,12 @@ class SqliteConnectionPool with SqliteQueries implements SqliteConnection {
   @override
   Future<void> close() async {
     closed = true;
-    await _writeConnection?.close();
     for (var connection in _readConnections) {
       await connection.close();
     }
+    // Closing the write connection cleans up the journal files (-shm and -wal files).
+    // It can only do that if there are no other open connections, so we close the
+    // read-only connections first.
+    await _writeConnection?.close();
   }
 }

test/close_test.dart

@@ -0,0 +1,53 @@
+import 'dart:io';
+
+import 'package:sqlite_async/sqlite_async.dart';
+import 'package:test/test.dart';
+
+import 'util.dart';
+
+void main() {
+  group('Close Tests', () {
+    late String path;
+
+    setUp(() async {
+      path = dbPath();
+      await cleanDb(path: path);
+    });
+
+    tearDown(() async {
+      await cleanDb(path: path);
+    });
+
+    createTables(SqliteDatabase db) async {
+      await db.writeTransaction((tx) async {
+        await tx.execute(
+            'CREATE TABLE test_data(id INTEGER PRIMARY KEY AUTOINCREMENT, description TEXT)');
+      });
+    }
+
+    test('Open and close', () async {
+      // Test that that the journal files are properly deleted after closing.
+      // If the write connection is closed before the read connections, that is
+      // not the case.
+
+      final db = await setupDatabase(path: path);
+      await createTables(db);
+
+      await db.execute(
+          'INSERT INTO test_data(description) VALUES(?)', ['Test Data']);
+      await db.getAll('SELECT * FROM test_data');
+
+      expect(await File('$path-wal').exists(), equals(true));
+      expect(await File('$path-shm').exists(), equals(true));
+
+      await db.close();
+
+      expect(await File(path).exists(), equals(true));
+
+      expect(await File('$path-wal').exists(), equals(false));
+      expect(await File('$path-shm').exists(), equals(false));
+
+      expect(await File('$path-journal').exists(), equals(false));
+    });
+  });
+}