WaitFor* command currently only result in a warning (https://github.com/vmi/selenese-runner-java/blob/master/src/main/java/jp/vmi/selenium/selenese/command/Assertion.java#L145). With Selenium IDE, they result in an error:

When these commands fail, they usually represent a test failure (element not present that was expected etc.). I'm using the this library programatically to integrate side tests in JUnit. When these commands only result in a warning, the test does not fail as it should. As a workaround, I'm now checking whether the result message contains the text "Assertion failed".

Can this be changed to an error?