Our FR5 mock accepts a call the real interface does not have

Developer replaced the catch-all behaviour with the documented methods we actually use. The misspelled call now fails. Response parsing is still barely tested.

Give it representative documented success, failure and incomplete replies, then check what the application does with each. Returning a convenient true value bypasses the parser you are trying to exercise.

What happens if you remove the result-read call entirely? Does opening the screen still count as a pass?

Yes. That test still passes without a read. I have added that as a known failing case for the developer.

Our display retained a previous result after the next read failed. Sequence tests caught it; separate screenshots of success and failure did not.

Liam's sequence is worth adding. Also start with no successful reading, so an old default cannot pretend to be the last known result.

And distinguish a failed read from an actual inspection rejection. They can both be non-successful outcomes for the software, but the person at the bench needs different explanations.

The success-then-failure sequence exposed a stale accepted colour. Developer fixed it and added current-read validity. Missing and incomplete replies now show no usable result, not rejected bracket.

Did the no-read test get fixed as well, Sara? Easy to lose that one once the colours behave.

Yes. It requires the expected read and validates the parsed result. Removing the call fails. Unknown method, wrong arguments, incomplete reply and initial no-result cases also pass their intended checks.

Have the tutor read the failure wording. We thought unavailable was clear until somebody took it to mean the bracket was physically missing from the fixture.

Tutor distinguished read failed from rejected bracket in the offline sequence. Mock and parser test work is complete. Installed interface comparison remains for commissioning; these tests make no claim about physical handling.

Keep the deliberately broken examples with the tests. They show why this substitute is useful much better than a page of green results alone.