tighten_type_of_initializing_formals

Tighten type of initializing formal.

Tighten the type of an initializing formal if a non-null assert exists. This allows the type system to catch problems rather than have them only be caught at run-time.

BAD:

class A {
  A.c1(this.p) : assert(p != null);
  A.c2(this.p);
  final String? p;
}

GOOD:

class A {
  A.c1(String this.p);
  A.c2(this.p);
  final String? p;
}
​
class B {
  String? b;
  B(this.b);
}
​
class C extends B {
  B(String super.b);
}

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

linter:
  rules:
    - tighten_type_of_initializing_formals

If you're instead using the YAML map syntax to configure linter rules, add tighten_type_of_initializing_formals: true under linter > rules:

linter:
  rules:
    tighten_type_of_initializing_formals: true