flutter-fvm

name	flutter-fvm
version	2.3.0
description	Skill for professional Flutter development with FVM. Includes Dart 3+ patterns, optimized performance, mandatory accessibility, OWASP security, and resilience management (Error Handling).
category	development-workflow

Flutter with FVM & Modern Patterns

Flutter version manager combined with modern architecture, performance, and accessibility patterns for high-fidelity applications.

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🔒 Prerequisites (Mandatory)

This skill operates WITHIN the SDD framework. Before starting any technical execution: 0. Mode Check: Verify .hub-mode and apply token-distiller guidelines.

1. Context Check: Rehydrate state by reading .specs/project/STATE.md, .specs/project/MEMORY.md, and .specs/project/LEARNINGS.md.
2. Spec Check: Does the spec.md file exist with clear requirements and Acceptance Criteria (ACs)? (BDD mandatory for Medium+).
3. Plan Check: Does the plan.md file define the architecture and schemas, and include Mermaid diagrams?
4. Contract Check: Was the contract.md file established with validation sensors?
5. Task Check: Is the task list in .specs/project/tasks.md (or feature-specific) detailed and atomized?

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Goal

FVM ensures the environment. This skill ensures Technical Excellence through:

Pillar	Main Focus
Dart 3+	Sealed classes, Pattern Matching, and Records for type safety.
Performance	Rebuild optimization (MediaQuery.sizeOf), RepaintBoundaries, and Decomposition.
UX/Accessibility	Semantics, touch targets (48x48), and dynamic contrast.
Resilience	Global error capture and graceful failure handling.
Security	OWASP Mobile Top 10 and secure Secrets management (--dart-define).

Version Awareness

Recommended Version: Flutter Stable (latest available via FVM)

Check the installed and active project versions:

fvm list
fvm current

When to Use This Skill

Use this skill when:

• Initializing a new Flutter project or migrating to Dart 3+.
• Implementing complex business logic with State Management (Riverpod/Bloc).
• Optimizing screen performance with complex lists or animations.
• Ensuring the app is accessible via screen readers (TalkBack/VoiceOver).
• Setting up robust error handling and crash reporting.
• Managing secrets and API keys securely.
• Performing OWASP Mobile Top 10 security analysis.

Skip this skill when:

• The project does NOT use Flutter/Dart.

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Workflow (4 Phases)

Phase 1: ENVIRONMENT — Configuration and Alignment

1. SDK Version: Set with fvm use stable.
2. Rigorous Linting: Configure analysis_options.yaml with strict-casts: true, strict-inference: true, and strict-raw-types: true.

Phase 2: PROJECT — Structure and Modernization

1. State Modeling: Use sealed class to represent states (Initial, Loading, Data, Error).
2. Secrets Management: Create structure to receive keys via --dart-define or .env (excluded from git).
3. Error Boundaries: Configure FlutterError.onError in main.dart.

Phase 3: DEVELOP — Quality and Performance

1. Decomposition: Keep build() methods under 100 lines.
2. Selective Rebuilds: Prefer MediaQuery.sizeOf(context) over MediaQuery.of(context).
3. Accessibility: Add semanticLabel to all critical visual elements.
4. Testing: Cover sealed state transitions and error flows.

Phase 4: DEPLOY — Security and Resilience

1. Crash Reporting: Ensure integration with Sentry/Crashlytics.
2. Hardening: Run builds with --obfuscate --split-debug-info.
3. Validation: Verify that no print statements remain (use debugPrint or log).

Output Structure

The execution of this skill results in the generation or update of the following artifacts:

Artifact	Location	Description
FVM Config	.fvm/fvm_config.json	Definition of the SDK version for the team.
Analysis Options	analysis_options.yaml	Linting and static analysis rules.
Sealed States	lib/features/*/domain/	Exhaustive state modeling.
Secure Secrets	.env / main.dart	Key management via environment.

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Quality Rules

DO:

• Use sealed classes to ensure exhaustiveness in state handling.
• Use const constructors aggressively to reduce GC pressure.
• Ensure touch targets are at least 48x48 dp.
• Use RepaintBoundary on animations or heavy drawing widgets.
• Validate context.mounted after any await.

DON'T:

• Do not use multiple booleans (isLoading, hasError) for screen states.
• Do not use print() in production; use the logging package or dart:developer.
• Do not ignore errors from fvm flutter analyze.
• Do not store secrets directly in Dart code (hardcoded).

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Reference Documentation

1. Modern Dart Patterns — Sealed classes, Records, and Pattern Matching.
2. Performance & Optimization — Rebuilds, RepaintBoundaries, and GC.
3. Accessibility Guide — Semantics, Hit Targets, and Inclusive UX.
4. Environment Setup — FVM and Strict Analyzer.
5. Flutter Security Guide — OWASP and Secrets.
6. Testing & Quality — State and Logic testing.

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Prohibited

• Do Not Skip Accessibility: Features without semantic labels or small targets are considered incomplete.
• Do Not Ignore the Analyzer: Analysis errors prevent deployment.
• Do Not Use Global Flutter: Maintain project isolation via FVM.

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version: "2.3.0"
feature_id: "HUB-ALIGNMENT"
phase: "VERIFY"
status: "COMPLETED"
last_update: "2026-05-06T13:16:19.364145Z"
evidence_checksum: "8e52f6a"