enable_null_safety

Do use sound null safety.

NOTE: This rule is removed in Dart 3.0.0; it is no longer functional.

DO use sound null safety, by not specifying a dart version lower than 2.12.

BAD:

// @dart=2.8
a() {
}

GOOD:

b() {
}

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

linter:
  rules:
    - enable_null_safety

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

linter:
  rules:
    enable_null_safety: true