APIs-guru
Add tests using moto and pyopenapi
The AWS v4 signing process makes it difficult to test that these specs actually work against the real AWS API, but moto has an option to disable authentication, and has a "standalone server" mode where it looks like the AWS API (which is why it's the basis of localstack).
I think it would be possible to get some local tests running (and even some CI) by using this, perhaps using something like pyopenapi.
Although that doesn't appear to support 3.0 yet, and I don't know if it supports XML.
There is also https://www.npmjs.com/package/aws-sdk-mock in node.js land.
Taking another look at pyopenapi, it doesn't appear to be ready to use. See this issue about updating the README from 2018.
Unfortunately pyswagger only supports 2.0 specs.
It might still be useful to use moto though, maybe just with openapi-generator as a test setup step.
I'm not sure if the mock for node.js has this, but the main reason I brought up moto is the standalone server mode.