specify_parameter_names

Description

Specify names for the parameters of Function types.

Details

Dart allows omitting the name of parameters in function types:

class LayoutBuilder {
  LayoutBuilder({this.builder});

  final Widget Function(BuildContext, ConstraintType) builder;
}

While that is legal, it degrades the experience of anyone using this widget with code completion in IDEs:

Since no names were given, unhelpful names are generated. This can be avoided by giving the parameters proper names:

class LayoutBuilder {
  LayoutBuilder({this.builder});

  final Widget Function(BuildContext context, ConstraintType constraints) builder;
}

The proposed lint would enforce that function types must always contain names for the parameters to improve the experience for anyone using IDE and code completion.

See also flutter/flutter#119877.

Kind

Maybe style? It's kinda a usability thing when people work with IDEs, though.

Bad Examples

Widget Function(BuildContext, ConstraintType) builder;
typedef BuilderCallback = Widget Function(BuildContext, ConstraintType);

Good Examples

Widget Function(BuildContext context, ConstraintType constraints) builder;
typedef BuilderCallback = Widget Function(BuildContext context, ConstraintType constraints);