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prefer-null-aware-spread

added in: 1.11.0
style
Pro+
preset: recommended

Warns when a null check inside a collection literal can be replaced with a null-aware spread (...?).

Example​

❌ Bad:

void fn() {
  final Set<String>? localSet = <String>{};

  final collection = [
    if (localSet != null) ...localSet, // LINT: Prefer null-aware spread (...?) instead of checking for a potential null value.
    ...localSet != null ? localSet : <String>{}, // LINT: Prefer null-aware spread (...?) with the then branch expression.
    ...localSet ?? {}, // LINT: Prefer null-aware spread (...?) instead of if-null (??).
  ];
}

✅ Good:

void fn() {
  final Set<String>? localSet = <String>{};

  final collection = [
    ...?localSet,
    ...?localSet,
    ...?localSet,
  ];
}