test: Add some tests for logging

packages/go_router/test/logging_test.dart

@@ -2,17 +2,70 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:async';
+
+import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
+import 'package:go_router/go_router.dart';
 import 'package:go_router/src/logging.dart';
 import 'package:logging/logging.dart';
 
 void main() {
   test('setLogging does not clear listeners', () {
-    log.onRecord
-        .listen(expectAsync1<void, LogRecord>((LogRecord r) {}, count: 2));
+    final StreamSubscription<LogRecord> subscription = logger.onRecord.listen(
+      expectAsync1<void, LogRecord>((LogRecord r) {}, count: 2),
+    );
+    addTearDown(subscription.cancel);
+
     setLogging(enabled: true);
-    log.info('message');
+    logger.info('message');
     setLogging();
-    log.info('message');
+    logger.info('message');
   });
+
+  testWidgets(
+    'It should not log anything the if debugLogDiagnostics is false',
+    (WidgetTester tester) async {
+      final StreamSubscription<LogRecord> subscription =
+          Logger.root.onRecord.listen(
+        expectAsync1((LogRecord data) {}, count: 0),
+      );
+      addTearDown(subscription.cancel);
+      GoRouter(
+        routes: <RouteBase>[
+          GoRoute(
+            path: '/',
+            builder: (_, GoRouterState state) => const Text('home'),
+          ),
+        ],
+      );
+    },
+  );
+
+  testWidgets(
+    'It should not log the known routes and the initial route if debugLogDiagnostics is true',
+    (WidgetTester tester) async {
+      final List<String> logs = <String>[];
+      Logger.root.onRecord.listen(
+        (LogRecord event) => logs.add(event.message),
+      );
+      GoRouter(
+        debugLogDiagnostics: true,
+        routes: <RouteBase>[
+          GoRoute(
+            path: '/',
+            builder: (_, GoRouterState state) => const Text('home'),
+          ),
+        ],
+      );
+
+      expect(
+        logs,
+        const <String>[
+          'Full paths for routes:\n  => /\n',
+          'setting initial location null'
+        ],
+      );
+    },
+  );
 }