Robert Adkins

> `type` is required to be a string. Ah, sorry I've actually overloaded `type` here. In ``` "type": { "const": "Cat" }, ``` `type` is the name of a property...

The OpenAPI spec includes the `const` keyword as of version 3.1 and was explicitly addressed as part of https://github.com/OAI/OpenAPI-Specification/pull/1977. From the [spec](https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.1.0.md): > The Schema Object allows the definition of...

Ah, I see! So only v3.0 is currently supported here. Any opposition to starting v3.1 support with this change? Adding `const` should be a non-breaking update to v3.0 parsing.

Since `const` was added in OpenAPI v3.1 (see discussion in #1834), updating this PR to only modify the v3 parsing and tests.