Expected Behavior

"version" is required by the library or filled in automatically in order to comply with this part of the spec.

Perhaps OpenApiService::new could required this and title (also required) as parameters? Though that'd be a breaking change which you may want to avoid. You could also make the builder return a Result to check for required params at startup, but that is also a breaking change.

The examples should also probably include version, perhaps using a macro to include the Cargo.toml version (I think this is possible and is probably what I'll do eventually).

Actual Behavior

"version" can be omitted (as it is in the examples I followed) which can lead to validation errors in other tools.

Steps to Reproduce the Problem

Omit the .version() method in setting up OpenApiService and observe that the generated document does not contain a version field under info.

Specifications

[dependencies]
poem = { version = "1.0.24", features = ["multipart", "tempfile"] }
poem-openapi = "1.0.20"