Add Store.isOpen.

Author: greenrobot-team

objectbox/lib/src/native/store.dart

@@ -266,6 +266,17 @@ class Store {
     }
   }
 
+  /// Returns if an open store was found for the given directory
+  /// (i.e. opened before and not yet closed).
+  static bool isOpen(String directory) {
+    final cStr = directory.toNativeUtf8();
+    try {
+      return C.store_is_open(cStr.cast());
+    } finally {
+      malloc.free(cStr);
+    }
+  }
+
   /// Returns a store reference you can use to create a new store instance with
   /// a single underlying native store. See [Store.fromReference] for more details.
   ByteData get reference => _reference;

objectbox/test/basics_test.dart

@@ -77,6 +77,15 @@ void main() {
     env.close();
   });
 
+  test('store is open', () {
+    expect(false, Store.isOpen(''));
+    expect(false, Store.isOpen('testdata-basics'));
+    final env = TestEnv('basics');
+    expect(true, Store.isOpen('testdata-basics'));
+    env.close();
+    expect(false, Store.isOpen('testdata-basics'));
+  });
+
   test('transactions', () {
     final env = TestEnv('basics');
     expect(TxMode.values.length, 2);