The input schema draft version should be used in all validators about hypothesis-jsonschema

[Stranger6667]

Update. I had a slight problem in my code - now there are no perf regressions :) Will push the new version soon

[Zac-HD]

Huh, I'm surprised this didn't come up earlier. Rather than threading the validator we need through everywhere, how about we rip off this trick:

https://github.com/Zac-HD/hypothesis-jsonschema/blob/c1a12bb034679751a802bbb03efcbcab00d09e18/tests/test_from_schema.py#L268-L271

and just define a get_validator_for(schema) function which tries the upstream get_validator, and falls back to the Draft4Validator if .check_schema() raises? This is might be conceptually pretty dodgy, but the code will look a lot nicer!

[Stranger6667]

It seems like a feasible approach, at least short-term. But I am concerned that it might cause potential problems in the future - for example, when Draft 2019-09 will be more common, and it will be the default validator, then it might be ambiguous what fallback should be used. Luckily, there are no backward-incompatible changes between Draft 6 & 7, so using Draft 4 should be ok.

Another thing is that for recursive schemas, there could be some more pieces to pass along - e.g., ref resolver. I was wondering if it might make sense to create a "context" object that could contain everything needed instead of passing dependencies as separate arguments. In this case, there could be a resolver and a validator, and extending it might be easier than adding new args across the codebase.

However, I feel perfectly fine with fallback to Draft 4 now - it still can be redesigned later if needed.

[Zac-HD]

From memory all draft7 schemas are also valid in draft 2019-09, so let's stick with the simple solution for now. As you say, we can always change it over later if it stops working!

[Stranger6667]

I found another small issue - the test suite run becomes consistently ~25% slower :( I will push the new version in a separate commit - maybe there is something with the implementation itself