Contents

avoid_returning_this

Contents

Avoid returning this from methods just to enable a fluent interface.

This rule is available as of Dart 2.0.

Details

#

From Effective Dart:

AVOID returning this from methods just to enable a fluent interface.

Returning this from a method is redundant; Dart has a cascade operator which allows method chaining universally.

Returning this is allowed for:

  • operators
  • methods with a return type different of the current class
  • methods defined in parent classes / mixins or interfaces
  • methods defined in extensions

BAD:

dart
var buffer = StringBuffer()
  .write('one')
  .write('two')
  .write('three');

GOOD:

dart
var buffer = StringBuffer()
  ..write('one')
  ..write('two')
  ..write('three');

Usage

#

To enable the avoid_returning_this rule, add avoid_returning_this under linter > rules in your analysis_options.yaml file:

analysis_options.yaml
yaml
linter:
  rules:
    - avoid_returning_this