Flutter Idiomatic FlutterSAFE

A collection of Agent Skills Standard and Best Practice for Programming Languages, Frameworks that help our AI Agent follow best practies on frameworks and programming laguages

The instruction file, verbatim from the audited commit — this is the text the model reads, and the surface the audit's instruction layer examines. Quoted here so you can judge it without cloning anything.

---
name: flutter-idiomatic-flutter
description: Compose modern Flutter layouts and widgets idiomatically. Use for widget trees, layout constraints, mounted safety, and UI composition—not BLoC state management, routing, dependency injection, or tests.
metadata:
  triggers:
    files:
    - 'lib/presentation/**/*.dart'
    - 'context.mounted'
    keywords:
    - SizedBox
    - Gap
    - composition
    - shrink
---
# Idiomatic Flutter

## **Priority: P1 (HIGH)**

- **Async Gaps**: Check `if (context.mounted)` before using `BuildContext` after `await`.
- **Composition**: Extract complex UI into small widgets. Avoid deep nesting or large helper methods.
- **Layout**:
  - Spacing: Prefer `spacing` parameter on `Row`/`Column` (Flutter 3.27+) over inserting `SizedBox`/`Gap` between children. On earlier Flutter versions, use `Gap(n)` instead — `spacing` will not compile.
  - Fallback: Use `Gap(n)` or `SizedBox` only when `spacing` cannot express the layout (e.g., conditional gaps).
  - Empty UI: Use `const SizedBox.shrink()`.
  - Intrinsic: Avoid `IntrinsicWidth/Height`; use `Stack` + `FractionallySizedBox` for overlays.
  - Spacing: Use `Gap(n)` or `SizedBox` over `Padding` for simple gaps.
  - Optimization: Use `ColoredBox`/`Padding`/`DecoratedBox` instead of `Container` when possible.
  - Themes: Use extensions for `Theme.of(context)` access.

## Anti-Patterns

- **No BuildContext after await without mounted check**: Check `context.mounted` to prevent crashes across async gaps.
- **No _buildXxx() helper methods**: Extract to `const StatelessWidget` for proper rebuild control.
- **No direct controller access in widget**: Use BLoC or Riverpod to decouple UI from state.
- **No Container for empty space**: Use `const SizedBox.shrink()`.

SAFEgrade B · trust 89/100 Nothing in the source contradicts what it says it does. Grade A is reserved for packages that have also passed the behavioural sandbox.

What the source does

Filesystem

none-observed

Network

none-observed

Shell

none-observed

Dependencies

pinned

Secrets in source

none-found

Findings (0)

No findings outside the package's declared scope.

Gates applied: no_behavioural_pass.