(testAppender: StringAdd).self
(testAppender: StringFormat).self
(testAppender: ArrowAssoc[TestAppender]).x
(Since version 2.10.0) Use leftOfArrow
instead
(testAppender: Ensuring[TestAppender]).x
(Since version 2.10.0) Use resultOfEnsuring
instead
A custom appender for Logback that captures the events.
The test suite can use this to make sure all log events are recorded as expected.