always_put_required_named_parameters_first     
            
            Put required named parameters first.
This rule is available as of Dart 2.0.0.
This rule has a quick fix available.
Details
DO specify required on named parameter before other named parameters.
BAD:
m({b, c, required a}) ;
GOOD:
m({required a, b, c}) ;
BAD:
m({b, c, @required a}) ;
GOOD:
m({@required a, b, c}) ;
Usage
To enable the always_put_required_named_parameters_first rule,
add always_put_required_named_parameters_first under linter > rules in your
analysis_options.yaml
file:
linter:
  rules:
    - always_put_required_named_parameters_first