question: How to get object state before it was transformed in Validator?

[rantiev]

Sometimes due to wrong object scheme we get undefined values as a result of transformation. Hence if you use IsOptional flag, you can't check was this field transformed wrong or it didn't exist in original object.

Hence there is no difference for IsOptional fields validation of undefined fields. They just skipped.

In my opinion IsOptional should skip values only if they were missing in original object. If they were transformed wrong we need to think that they didn't pass validation. (if they transformed wrong we got wrong object input - validation should fail as it checks scheme, even if transformed scheme)

I want to create my own @WasTransformedProperly() or @IsOptionaIfNotSetOriginally()
Or to check original object state in my custom validators...

Is this possible?

I see that other people are complaining about similar cases (IsOptional skipping undefined when it shouldn't) also.
What could we do with this? Any workaround, proposal or existing PRs?