contains<T, E> static method

Rule<Iterable<T>, E> contains<T, E>(
  1. T item, {
  2. required E error,
})

Validates that the collection contains item.

CollectionRules.contains('admin', error: 'Must include admin')

Implementation

static Rule<Iterable<T>, E> contains<T, E>(T item, {required E error}) =>
    PredicateRule(
      predicate: (value) => value.contains(item),
      error: error,
    );