### Bug fixes

* [#296](https://github.com/rubocop/rubocop-performance/pull/296): Fix a false negative for `Performance/StringIdentifierArgument` when using `instance_variable_defined?`. ([@koic][])
* [#294](https://github.com/rubocop/rubocop-performance/pull/294): Fix a false negative for `Performance/ChainArrayAllocation` when using `array.first(do_something).uniq`. ([@koic][])

[@koic]: https://github.com/koic
