effective-dart

Effective Dart Skill

This skill defines how to write idiomatic, high-quality Dart and Flutter code following Effective Dart guidelines.

---

1. Naming Conventions

Kind	Convention	Example
Classes, enums, typedefs, type parameters, extensions	UpperCamelCase	MyWidget, UserState
Packages, directories, source files	lowercase_with_underscores	user_profile.dart
Import prefixes	lowercase_with_underscores	import '...' as my_prefix;
Variables, parameters, named parameters, functions	lowerCamelCase	userName, fetchData()

• Capitalize acronyms and abbreviations longer than two letters like words: HttpRequest, not HTTPRequest.
• Avoid abbreviations unless the abbreviation is more common than the full term.
• Prefer putting the most descriptive noun last in names.
• Use terms consistently throughout your code.
• Follow mnemonic conventions for type parameters: E (element), K/V (key/value), T/S/U (generic types).
• Consider making code read like a sentence when designing APIs.
• Prefer a noun phrase for non-boolean properties or variables.
• Prefer a non-imperative verb phrase for boolean properties or variables; prefer the positive form.
• Consider omitting the verb for named boolean parameters.
• Avoid starting a function or method name with get; prefer removing get and using a getter when the API conceptually exposes a property.

---

2. Types and Functions

• Use class modifiers (final, sealed, interface, base, mixin) to control whether a class can be extended or implemented.
• Type annotate variables without initializers.
• Type annotate fields and top-level variables if the type isn't obvious.
• Annotate return types on function declarations.
• Annotate parameter types on function declarations.
• Write type arguments on generic invocations that aren't inferred.
• Annotate with dynamic instead of letting inference fail.
• Use Future<void> as the return type of async members that do not produce values.
• Use getters for operations that conceptually access properties.
• Use setters for operations that conceptually change properties.
• Use a function declaration to bind a function to a name.
• Use inclusive start and exclusive end parameters to accept a range.