test: smoke test repeated Wallet.keychains() calls across wallet lifecycle

test/keychains_lifecycle_smoke_test.dart

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+import 'dart:io';
+
+import 'package:bdk_dart/bdk.dart';
+import 'package:test/test.dart';
+
+import 'test_constants.dart';
+
+Future<void> _deleteDirectoryWithRetry(Directory dir) async {
+  for (var attempt = 0; attempt < 10; attempt++) {
+    try {
+      if (dir.existsSync()) {
+        await dir.delete(recursive: true);
+      }
+      return;
+    } on PathAccessException {
+      await Future<void>.delayed(const Duration(milliseconds: 100));
+    }
+  }
+  if (dir.existsSync()) {
+    await dir.delete(recursive: true);
+  }
+}
+
+String _createTempSqlitePath() {
+  final tempDir = Directory.systemTemp.createTempSync(
+    'bdk_dart_keychains_lifecycle_',
+  );
+  addTearDown(() => _deleteDirectoryWithRetry(tempDir));
+  return '${tempDir.path}/wallet.sqlite';
+}
+
+Wallet _reloadWallet(
+  Wallet current,
+  Descriptor descriptor,
+  Descriptor changeDescriptor,
+  Persister persister,
+) {
+  current.dispose();
+  return Wallet.load(
+    descriptor: descriptor,
+    changeDescriptor: changeDescriptor,
+    persister: persister,
+    lookahead: defaultLookahead,
+  );
+}
+
+void _expectUsableKeychains(List<WalletKeychain> keychains) {
+  expect(keychains, isA<List<WalletKeychain>>());
+  expect(keychains.length, greaterThanOrEqualTo(2));
+
+  for (final entry in keychains) {
+    expect(
+      entry.keychain,
+      isIn([KeychainKind.external_, KeychainKind.internal]),
+    );
+    expect(entry.publicDescriptor, isA<Descriptor>());
+    entry.publicDescriptor.descType();
+    entry.publicDescriptor.descriptorId();
+    entry.publicDescriptor.hasWildcard();
+  }
+}
+
+void main() {
+  group('Wallet keychains lifecycle smoke', () {
+    test(
+      'keychains() remains callable before and after sqlite persist/reload',
+      () {
+        final descriptor = buildBip84Descriptor(Network.testnet);
+        final changeDescriptor = buildBip84ChangeDescriptor(Network.testnet);
+        final sqlitePath = _createTempSqlitePath();
+        final persister = Persister.newSqlite(path: sqlitePath);
+        late Wallet wallet;
+        var walletInitialized = false;
+
+        try {
+          wallet = Wallet(
+            descriptor: descriptor,
+            changeDescriptor: changeDescriptor,
+            network: Network.testnet,
+            persister: persister,
+            lookahead: defaultLookahead,
+          );
+          walletInitialized = true;
+
+          _expectUsableKeychains(wallet.keychains());
+
+          wallet.persist(persister: persister);
+
+          wallet = _reloadWallet(
+            wallet,
+            descriptor,
+            changeDescriptor,
+            persister,
+          );
+
+          _expectUsableKeychains(wallet.keychains());
+        } finally {
+          if (walletInitialized) {
+            wallet.dispose();
+          }
+          persister.dispose();
+          descriptor.dispose();
+          changeDescriptor.dispose();
+        }
+      },
+    );
+  });
+}