When a test is failing we get the last-page.html and a heap-dump.log to ease debugging and we put them under target/diagnostic/failed-test-name

FailureDiagnostics class is responsible for adding every file under target/diagnostic/failed-test-name as a junit attachment using failed() method from TestWatcher.

The issue os that this failed() method is called before the last-page.html and heap-dump.log are generated so they are not added as attachment.