the reason for 0 as return is within a CI environment, those tools most of the time expect an external tool triggered to return an error code, where 0 is the universal indicator for ERROR_SUCCESS (no errors). So your CI server would with that know that the step succeeded and continue with the next step or end the pipeline run successfully.
By default Webtestit just creates JUnit files as a result. You can find these in the /reports folder. The reason for that is that most CI servers (Jenkins, TFS, …) have means to interpret JUnit files and create their dashboards from it. Alternatively tools like Allure Report also make use of JUnit as the format to generate HTML reports. So as you can see we picked that as it is kinda the most used generic data format for test results.
Now as @smatijas explained we’re already investigating a solution to create PDFs along the XML as an output. That has impacts on the CLI though as it requires UI access (even if hidden) which is fine with the current approach of how our CLI works by being part of the whole IDE. Splitting things up though would create troubles for that feature.
So long story short, we’re on it but it’ll might take a bit longer to find the best way forward.