Bloc Signals

BlocSignal

Start from installed source

BlocSignal is young and its API may change between releases. Inspect the consumer project's pubspec.yaml, lockfile, imports, and installed package source before editing code. Use this repository only when the project follows its current branch or the task concerns the repository itself.

Do not infer API parity from package:bloc, package:flutter_bloc, or Riverpod. BlocSignal uses signals, has no state stream or provider dependency graph, and does not implement every source package lifecycle, predicate, or widget API.

Related Signals skills

This plugin is self-contained for BlocSignal work. When the agent already has skills from rodydavis/signals.dart, use these optional companions for lower-level Signals tasks:

• signals-dart for signals_core primitives and utilities.
• signals-flutter for Flutter bindings and signal-aware widgets.
• signals-hooks for flutter_hooks integration.
• signals-lint for analyzer rules and quick fixes.
• signals-migration-6-to-7 for Signals 6 to 7 migrations.

Do not assume these skills are installed. If they are unavailable, inspect the consumer project's installed Signals source before changing code.

Route the task

• Read decision_matrix.md for the architectural decision rubric comparing raw Signals, CubitSignal, BlocSignal, Hydrate, and Replay.
• Read core.md for event dispatch, equality, errors, closure, observers, and reactive ownership.
• Read flutter.md for providers, builders, listeners, multi-listeners, consumers, selectors, context extensions, infinite scroll pagination recipes, flutter_hooks integration (signals_hooks), widget ownership, and derived UI state.
• Read testing.md for synchronous assertions, deterministic async tests, zones, and widget tests.
• Read migration.md before replacing bloc, flutter_bloc, bloc_concurrency, hydrated_bloc, replay_bloc, or bloc_test.
• Read migration_bridge.md for Stream and Listenable interop bridges.
• Read riverpod_migration.md before replacing Riverpod providers, consumers, families, scopes, or generated declarations.
• Read interoperability.md for the universal state bridge across BLoC, Riverpod, and Provider ecosystems.
• Read hydration.md for persistent state storage (bloc_signals_hydrate).
• Read replay.md for undo and redo state tracking (bloc_signals_replay).
• Read jaspr.md for Jaspr web component integration (bloc_signals_jaspr).
• Read devtools.md for VM Service RPC extensions & DevTools UI (bloc_signals_devtools).
• Read lint.md for analyzer rules and IDE diagnostics (bloc_signals_lint).
• Read otel.md for OtelBlocSignalObserver, span completion gaps, and telemetry data choices.

Load only the references needed for the task.

Workflow

1. Identify the exact package versions and target platform.
2. Trace the current event, state, ownership, and disposal path before changing it.
3. Check the installed public API for every type or member you plan to use.
4. Make the smallest coherent change that preserves existing user behavior.
5. Format changed Dart files and run scoped analysis plus the nearest tests.
6. Report the versions inspected, checks run, and any unsupported source behavior that remains.

Contracts to preserve

• BlocSignalBase<State> owns state and lifecycle. Use CubitSignal<State> for public methods and BlocSignal<Event, State> for event dispatch. Use CubitSignalMixin<State> or BlocSignalMixin<Event, State> when a class already extends an existing superclass (such as ChangeNotifier, TextEditingController, or BaseRepository) and invoke initCubitSignal(initialState: ...) in the constructor.
• Constructors require named parameter initialState: (for example : super(initialState: initial)), NOT positional super(initial).
• Use stateValue to read raw StateType values inside methods/handlers (such as emit(stateValue + 1)). state returns ReadonlySignal<StateType> for reactive signal subscriptions.
• emit changes state synchronously and skips a value equal to the current state.
• BlocSignal.add returns void. Synchronous handlers finish before it returns. Async handler futures are observed for errors but are not returned or cancelled by close.
• on<E> registration is runtime routing. Duplicate exact types throw StateError; registration does not give sealed-class exhaustiveness. An onEvent override must call super.onEvent.
• close returns Future<void>, disposes effects registered through createEffect, and disposes the internal model. New events are dropped after closure. A post-close emit asserts in debug mode and returns without updating state in release mode.
• A non-equal event transition runs before state mutation. onChange runs after mutation. Both local hooks require super; equal emits run neither hook.
• BlocSignalProvider(create:) is lazy by default, owns its bloc, and closes it. Use lazy: false for eager creation. BlocSignalProvider.value does not own its bloc. Both BlocSignalProvider and BlocSignalListener support an optional child parameter (defaulting to const SizedBox.shrink() in Flutter and const _NullComponent() in Jaspr), eliminating placeholder child arguments inside MultiBlocSignalProvider or MultiBlocSignalListener.
• context.watch<T>() tracks provider replacement, not state changes. Use BlocSignalBuilder or a signals widget to rebuild for state.
• BlocSignalListener suppresses its initial effect run and supports listenWhen(previous, current). It passes only the current state to the listener callback.
• A global BlocSignalObserver is a single slot. Installing a telemetry observer can replace an existing logger unless the application composes them.
• BlocSignalBase overrides toString() to output $runtimeType($stateValue), providing immediate diagnostic visibility across all CubitSignal and BlocSignal subclasses.
• Prefer inline late final field declarations with type inference for computed properties (for example late final itemCount = computed(() => stateValue.items.length);) rather than uninitialized field declarations with constructor-body assignments.

Never create an effect or computed during a Flutter build method. Keep its owner and disposal path explicit.