See https://pekko.apache.org/docs/pekko/current/typed/testing-async.html#silence-logging-output-from-tests

JUnit Jupiter extension to make log lines appear only when the test failed.

Use this in test by adding @ExtendWith annotation:

@ExtendWith(LogCapturingExtension.class)

Requires Logback and configuration like the following the logback-test.xml:

<appender name="CapturingAppender" class="org.apache.pekko.actor.testkit.typed.internal.CapturingAppender" />

<logger name="org.apache.pekko.actor.testkit.typed.internal.CapturingAppenderDelegate" >
  <appender-ref ref="STDOUT"/>
</logger>

<root level="DEBUG">
    <appender-ref ref="CapturingAppender"/>
</root>

See https://pekko.apache.org/docs/pekko/current/typed/testing-async.html#silence-logging-output-from-tests

JUnit TestRule to make log lines appear only when the test failed.

Use this in test by adding a public field annotated with @Rule:

@Rule public final LogCapturingJunit4 logCapturing = new LogCapturingJunit4();

Requires Logback and configuration like the following the logback-test.xml:

<appender name="CapturingAppender" class="org.apache.pekko.actor.testkit.typed.internal.CapturingAppender" />

<logger name="org.apache.pekko.actor.testkit.typed.internal.CapturingAppenderDelegate" >
  <appender-ref ref="STDOUT"/>
</logger>

<root level="DEBUG">
    <appender-ref ref="CapturingAppender"/>
</root>