git:20260822.e519e06 to git:20260823.5691dc4

2 added, 1 removed. Audit A to A.

---

name: dart-language

description: Apply modern Dart language and API patterns in non-concurrency code. Use for types, records, patterns, sealed classes, extensions, constructors, null safety, collections, and package APIs; route async and isolate work to dart-concurrency.

---

# Dart Language

Write clear Dart that fits the project's SDK constraint and established style.

## Decisions

- Read the SDK constraint in `pubspec.yaml` before using newer syntax.

- Prefer simple types and direct control flow over abstractions with no demonstrated reuse.

- Model closed variants with sealed types when exhaustive switching improves correctness.

- Use records for small structural values; use named domain types when identity, validation, documentation, or evolution matters.

- Use pattern matching when it makes branching or destructuring clearer, not as a novelty.

- Preserve public API compatibility unless a breaking change is requested.

- Keep mutable state private and expose the smallest useful surface.

Follow Effective Dart naming, documentation, usage, and design guidance. Match repository lint rules rather than adding conflicting style policy.

## Verification

- Run formatting, static analysis, and the narrowest relevant tests. When changing a public package API, check examples and downstream call sites.

+ Use Dart MCP semantic lookup and analysis when the current environment exposes them; otherwise inspect source and use the project CLI. Run formatting, static analysis, and the narrowest relevant tests. When changing a public package API, check examples and downstream call sites.

## Boundaries

- Async, streams, cancellation, and isolates: use `dart-concurrency`.

- Flutter widget composition or state ownership: use the relevant Flutter skill.

- JSON and persistence schema behavior belongs to the corresponding data skill.

## Sources

- [Dart language](https://dart.dev/language)

- [Effective Dart](https://dart.dev/effective-dart)

+ - [Dart and Flutter MCP server](https://docs.flutter.dev/ai/mcp-server)