test_types_in_equals

Test type of argument in operator ==(Object other).

DO test type of argument in operator ==(Object other).

Not testing the type might result in runtime type errors which will be unexpected for consumers of your class.

BAD:

class Field {
}
​
class Bad {
  final Field someField;
​
  Bad(this.someField);
​
  @override
  bool operator ==(Object other) {
    Bad otherBad = other as Bad; // LINT
    bool areEqual = otherBad != null && otherBad.someField == someField;
    return areEqual;
  }
​
  @override
  int get hashCode {
    return someField.hashCode;
  }
}

GOOD:

class Field {
}
​
class Good {
  final Field someField;
​
  Good(this.someField);
​
  @override
  bool operator ==(Object other) {
    if (identical(this, other)) {
      return true;
    }
    return other is Good &&
        this.someField == other.someField;
  }
​
  @override
  int get hashCode {
    return someField.hashCode;
  }
}

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

linter:
  rules:
    - test_types_in_equals

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

linter:
  rules:
    test_types_in_equals: true