disallowing unknown attributes

[adityasarawatexponential]

I want to prevent the attributes that are not present in schema.

[jviotti]

@Relequestual Would it make sense to offer a "strict" version of the official meta-schemas? I found myself looking for this now and then, as its very easy to make a typo, etc without realizing.

[handrews]

@adityasarawatexponential the unevaluatedProperties keyword was added to solve this problem. The idea of requiring implementations to support a "strict mode" was one of the controversies that led to the near-collapse of the project after draft-04 (none of the people directly involved in that debate are still with the project). At least one major implementation has such a mode and from what I can tell it also causes confusion.

@jviotti one of my motivations for adding both unevaluatedProperties and what eventually became $dynamicRef is that with those two keywords it's trivial to make a strict meta-schema.

@Relequestual would "how to make a strict meta-schema" be a good blog post? I could write that one pretty quickly I think, just as a straightforward tutorial. Not an in-depth exploration of theory 😜