avoid-missing-interpolation

added in: 1.9.0

warning

⚙️

Pro+

Warns when a string is equal to a variable name that is available in the current scope but is not wrapped into an interpolation.

⚙️ Config

Set ignore-non-string-types (default is true) to ignore variables with non-string type.

dart_code_metrics:
  ...
  rules:
    ...
    - avoid-missing-interpolation:
        ignore-non-string-types: true

Example

❌ Bad:

void main() {
  final someClass = SomeClass('hello');

  print('someClass'); // LINT
  print('value: $someClass.value'); // LINT
  print('isNotEmpty: $someClass.value.isNotEmpty'); // LINT

  print('$function(value)'); // LINT
}

String function(String value) {
  print('value'); // LINT

  return 'result value';
}

class SomeClass {
  final String value;

  const SomeClass(this.value);
}

✅ Good:

void main() {
  final someClass = SomeClass('hello');

  print(someClass);
  print('value: ${someClass.value}');
  print('isNotEmpty: ${someClass.value.isNotEmpty}');

  print('${function(value)}');
}

String function(String value) {
  print(value);

  return 'result value';
}

class SomeClass {
  final String value;

  const SomeClass(this.value);
}