otel_bloc 0.1.0-beta.1

OpenTelemetry instrumentation for `package:bloc`. A `BlocObserver` subclass that emits short event spans on every bloc event / state change / error, turning your Tempo trace view into a state-machine [...]

Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

0.1.0-beta.1 - 2026-05-14

Renamed

• Renamed from dartastic_flutter_bloc_otel to dartastic_bloc_otel to match the riverpod core/overlay pattern. The package only ever depended on bloc (the pure-Dart core that flutter_bloc re-exports); the flutter_ prefix was misleading. A new slim Flutter overlay ships under the original dartastic_flutter_bloc_otel name for flutter_bloc-based apps.

Added

• OTelBlocObserver — a BlocObserver that emits one short span per Bloc/Cubit lifecycle event (onCreate, onTransition for Bloc, onChange for Cubit, onError, onClose). Each span carries the bloc.* semconv attributes (bloc name + kind, event type, state before/after).
• onChange is suppressed for Blocs because onTransition fires immediately after it with strictly more info. Cubits get their own onChange spans since they don't go through events.
• onError is recorded via recordException then setStatus(Error), in OTel-spec order.
• BlocSemantics — typed attribute-key enum implementing OTelSemantic, package-local because OTel has no upstream semantic convention for state-machine frameworks yet.
• Constructor flags: recordLifecycle (default true), recordTransitions (default true), recordEventValues (default false), recordStateValues (default false), valueAttributeMaxLength (default 256).
• Targets bloc: ^9.0.0. Works with both flutter_bloc apps (which re-export bloc) and pure-Dart bloc apps.
• 6 unit tests covering: Bloc add → onCreate + onTransition + onClose (with onChange correctly suppressed), Cubit emit → onChange (with onTransition correctly absent), onError → Error status + exception event, recordEventValues + recordStateValues clipping, recordLifecycle false, recordTransitions false.
• 1 LGTM integration test polls Tempo round-trip.
• Example app produces a single run-scenarios trace with 16 spans across a Bloc-happy-path, Cubit-happy-path, and a Bloc-error scenario.