Panic on property name collision

[cjen1-msft]

If there are multiple properties with the same name, for example a Sometimes and a Eventually property, then the Sometimes discovery may be misattributed to an Eventually counterexample.

This prevents that by enforcing that all property names are unique.

[jeffa5]

Thanks for this, looks fine to me. Makes me wonder if we should use something other than the property name in the discovery checks though, like an internal id.

What do you think?

[jonnadal]

Thanks @cjen1-msft.

@jeffa5 I'm open to alternatives if they don't hurt the ergonomics too much. Somewhat related: I'm thinking in retrospect properties should be passed to the checker rather than being part of the Model so would probably start there first.