pleasefixai/dart-flutter

Write and organize unit tests for functions, methods, and classes using package:test. Use when creating new logic or fixing bugs to ensure code remains correct and regression-free.

Architectural patterns, entrypoint structure, exit codes, stream routing, and subprocess spawning for Dart command-line interface (CLI) applications. Use when building CLI tools, console utilities, scripts, argument parsing with package:args (ArgParser or CommandRunner), handling exit codes, configuring executables in pubspec.yaml, spawning Dart subprocesses, or compiling native CLI binaries. Don't use for Flutter UI widgets, web applications, or standalone HTTP backend servers.

Collect coverage using the coverage packge and create an LCOV report

Uses get_runtime_errors and lsp to fetch an active stack trace, locate the failing line, apply a fix, and verify resolution via hot_reload.

Define and generate mock objects for external dependencies using package:mockito and build_runner. Use when unit testing classes that depend on complex external services like APIs or databases.

Replace the usage of expect and similar functions from package:matcher to package:checks equivalents.

Workflow for fixing package version conflicts. Use this when pub get fails due to incompatible package versions.

Execute dart analyze to identify warnings and errors, and use dart fix --apply to automatically resolve mechanical lint issues. Use during development to ensure code quality and before committing changes.

Guides agents in compiling and packaging C/C++ source code into dynamic or static libraries (Code Assets) using Dart's Native Assets hook system (via hook/build.dart and hook/link.dart utilizing package:hooks and package:native_toolchain_c). Use when a user asks to: 'setup native assets', 'compile C/C++ source code', 'bundle dynamic libraries', 'build native C code', 'link native assets', 'implement build.dart or link.dart hooks', or 'integrate C/C++ interop in Dart/Flutter'. Helps agents avoid manual toolchain orchestration and configures secure hash-validated binary downloads or advanced linker tree-shaking with package:record_use mapping.

How to inject external code examples into Dartdoc using the {@example} directive, and how to filter those files using #hide, #region, and #endregion tags.

Guide agents to use package:ffigen to automatically generate FFI bindings instead of writing them manually. Use this skill when a task involves writing new FFI bindings, extending C/Objective-C/Swift integrations, or replacing hand-crafted dart:ffi setups.

Cross-platform file and directory path manipulation, segment splitting, extension extraction, and context conversion using package:path and package:file. Use when writing, inspecting, joining, splitting, or refactoring file paths, directory names, or extensions, or replacing raw string path operations (.split('/'), '$dir/$file', .endsWith('.ext'), .replaceAll('\\', '/')). Don't use for HTTP network URI routing, database query strings, or non-path string processing.

Applies Dart 3 pattern matching, switch expressions, and destructuring idiomatically to validate data schemas, handle algebraic data types, and decompose control flow. Use when refactoring complex if-else chains, parsing polymorphic JSON or API responses, destructuring Lists, URI/path segments, String.split() tokens, Records, or Maps, or enforcing exhaustiveness on sealed classes. Don't use for simple boolean conditions, single-variable type promotion (use is), or basic collection filtering.

Help users write syntactically and semantically correct primary constructors in Dart, and migrate/use the new constructor syntax, empty-body semicolon syntax, in-body initializer list syntax, and abbreviated concise constructor syntax.

Rules and formatting guidelines for writing Dart /// API documentation and doc comments. Use when documenting Dart code, writing doc comments for any Dart declaration (libraries, classes, methods, variables, etc.), or when instructed to follow the Effective Dart documentation guidelines.

Configures Flutter Driver for app interaction and converts MCP actions into permanent integration tests. Use when adding integration testing to a project, exploring UI components via MCP, or automating user flows with the integration_test package.

Adds interactive widget previews to the project using the previews.dart system. Use when creating new UI components or updating existing screens to ensure consistent design and interactive testing.

Implement a component-level test using WidgetTester to verify UI rendering and user interactions (tapping, scrolling, entering text). Use when validating that a specific widget displays correct data and responds to events as expected.

Architects a Flutter application using the recommended layered approach (UI, Logic, Data). Use when structuring a new project or refactoring for scalability.

Use LayoutBuilder, MediaQuery, or Expanded/Flexible to create a layout that adapts to different screen sizes. Use when you need the UI to look good on both mobile and tablet/desktop form factors.

Fixes Flutter layout errors (overflows, unbounded constraints). Use when addressing "RenderFlex overflowed", "Vertical viewport was given unbounded height", or similar layout issues.

Create model classes with fromJson and toJson methods using dart:convert. Use when manually mapping JSON keys to class properties for simple data structures.

Configure MaterialApp.router using a package like go_router for advanced URL-based navigation. Use when developing web applications or mobile apps that require specific deep linking and browser history support.

Add flutter_localizations and intl dependencies, enable "generate true" in pubspec.yaml, and create an l10n.yaml configuration file. Use when initializing localization support for a new Flutter project.

Use the http package to execute GET, POST, PUT, or DELETE requests. Use when you need to fetch from or send data to a REST API.