Merge pull request #341 from MojiMom/feature/untrackedValue

added untrackedValue

Author: rodydavis

packages/signals_flutter/lib/extended.dart

@@ -8,4 +8,5 @@ export 'src/flutter/scheduler_binding.dart';
 export 'src/flutter/inherited_widget/signal.dart';
 export 'src/flutter/inherited_widget/computed.dart';
 export 'src/flutter/inherited_widget/readonly.dart';
-export 'src/flutter/inherited_widget/provider.dart';
+export 'src/flutter/inherited_widget/provider.dart';
+export 'src/extensions/untracked_value.dart';

packages/signals_flutter/lib/src/extensions/untracked_value.dart

@@ -0,0 +1,13 @@
+import 'package:signals_core/signals_core.dart';
+
+/// Signal extensions
+extension ReadonlySignalUntrackedValueUtils<T> on ReadonlySignal<T> {
+  /// Runs a callback function that returns the signal value without
+  /// subscribing to the signal updates.
+  ///
+  /// ```dart
+  /// final counter = signal(0);
+  /// final untrackedValue = counter.untrackedValue;
+  /// ```
+  T get untrackedValue => untracked(() => value);
+}

packages/signals_flutter/test/extension/untracked_value_test.dart

@@ -0,0 +1,34 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:signals_flutter/extended.dart';
+import 'package:signals_flutter/signals_flutter.dart';
+
+void main() {
+  SignalsObserver.instance = null;
+  group('untrackedValue', () {
+    test('single', () {
+      final s = signal(0);
+      int calls = 0;
+      final dis = effect(() {
+        s.value;
+        s.untrackedValue + 1;
+        calls++;
+      });
+      dis();
+
+      expect(calls, 1);
+    });
+
+    test('nested', () {
+      final s = signal(0);
+      int calls = 0;
+      final dis = effect(() {
+        s.value;
+        untracked(() => s.untrackedValue + 1);
+        calls++;
+      });
+      dis();
+
+      expect(calls, 1);
+    });
+  });
+}