avoid-substring

added in: 1.6.0

warning

Free+

Warns when a String.substring method is used.

String.substring does not support UTF-16 which can result in unexpected output when a string contains emojis.

Use package:characters and characters.getRange instead.

Additional resources:

• https://github.com/dart-lang/sdk/issues/35798

Example

❌ Bad:

String someValue = '🙂';

someValue.substring(0, 1); // LINT

✅ Good:

String someValue = '🙂';

someValue.characters.getRange(0, 1);