В
$this->expectExeption(RuntimeException::class);приходится писать
$dispatcher->expectEvent(EventClass::class, 1);
doStuff();
$exception = null;
try {
doStuff();
} catch (RuntimeException $exception) {
} finally {
$this->assertInstanceOf($exception, RuntimeException::class);
$dispatcher->isInstanceOfTriggered(EventClass::class, 1);
}