Java – assertj asserts on the cause message

Is there any way to throw a method again when using assertj to check whether the message in the reason is equal to a string

I am currently doing something similar:

assertThatThrownBy(() -> SUT.method())
            .isExactlyInstanceOf(IllegalStateException.class)
            .hasRootCauseExactlyInstanceOf(Exception.class);

And I want to add an assertion to check the message in the root cause

Solution

Not exactly. At present, the best you can do is to use hasstacktracecontainer, for example

Throwable runtime = new RuntimeException("no way",new Exception("you shall not pass"));

assertThat(runtime).hasCauseInstanceOf(Exception.class)
                   .hasStackTraceContaining("no way")
                   .hasStackTraceContaining("you shall not pass");