unnecessary_const

Avoid const keyword.

This rule is available as of Dart 2.0.0.

Rule sets: recommended, flutter

This rule has a quick fix available.

AVOID repeating const keyword in a const context.

BAD:

class A { const A(); }
m(){
  const a = const A();
  final b = const [const A()];
}

GOOD:

class A { const A(); }
m(){
  const a = A();
  final b = const [A()];
}

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

linter:
  rules:
    - unnecessary_const