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prefer_is_not_empty

Use 'isNotEmpty' rather than negating the result of 'isEmpty'.

Description

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The analyzer produces this diagnostic when the result of invoking Iterable.isEmpty or Map.isEmpty is negated.

Example

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The following code produces this diagnostic because the result of invoking Iterable.isEmpty is negated:

dart
void f(Iterable<int> p) => !p.isEmpty ? p.first : 0;

Common fixes

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Rewrite the code to use isNotEmpty:

dart
void f(Iterable<int> p) => p.isNotEmpty ? p.first : 0;