prefer_is_not_empty

Use isNotEmpty for Iterables and Maps.

This rule is available as of Dart 2.0.0.

Rule sets: core, recommended, flutter

This rule has a quick fix available.

PREFER x.isNotEmpty to !x.isEmpty for Iterable and Map instances.

When testing whether an iterable or map is empty, prefer isNotEmpty over !isEmpty to improve code readability.

BAD:

if (!sources.isEmpty) {
  process(sources);
}

GOOD:

if (todo.isNotEmpty) {
  sendResults(request, todo.isEmpty);
}

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

linter:
  rules:
    - prefer_is_not_empty