[BUG][Swift6] Numerous compilation issues with Swift 6 generator + Alamofire 5.10.x

[lilidotshi]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?

Description

Updating to Alamofire 5.10.x causes multiple compilation issues around Sendable.

In particular, the following classes have issues:

Class	Error
extension JSONDataEncoding	Conformance to 'Sendable' must occur in the same source file as struct 'JSONDataEncoding'; use '@unchecked Sendable' for retroactive conformance
AnyResponseSerializer	Type 'AnyResponseSerializer.SerializedObject' (aka 'T') does not conform to the 'Sendable' protocol

openapi-generator version

7.10.0

Generation Details

This is one of the Infrastructure files generated along with any scheme.

Steps to reproduce

use the Swift 6 generator with the latest alamofire 5.10.x and observe that it does not compile due to a bunch of swift 6 errors

[x-sheep]

I looked into this for a bit.

Alamofire 5.10 enforces that all objects used in the request conform to Sendable. The core of the problem is this protocol in Models.swift:

protocol JSONEncodable {
    func encodeToJSON(codableHelper: CodableHelper) -> Any
}

If this protocol gained the requirement that all conforming types also conform to Sendable, this can be fixed by returning any Sendable instead (a new Swift 6 construct). The problem is that the following conditional conformance is impossible:

extension Array: JSONEncodable where Element: Sendable

Sendable is a marker protocol and JSONEncodable is not. So all types that may be used in a request should conform to JSONEncodable instead.

[4brunu]

Hi, this is a know issue.

openapi-generator/modules/openapi-generator/src/main/resources/swift6/Package.swift.mustache

Lines 28 to 29 in 3d65786

	// TODO: Alamofire versions 5.10.0 and above are not currently supported. If you need a newer version, please consider submitting a Pull Request with the required changes.
	.package(url: "https://github.com/Alamofire/Alamofire", exact: "5.9.1"),

Unfortunately, currently I don't have time to fix this issue, but if anyone can create a PR, I can help with the review and merge.
Thanks.

[x-sheep]

@4brunu A question about the current client: Could the JSONEncodable protocol and the encodeToJSON function be removed entirely? I don't know if it's a protocol that should ever be implemented by users, and the client code already compares types directly for different behavior (e.g. using URL for file uploads).

[4brunu]

That's a good question.
I think we could remove it, and I don't see a reason for the users to implement this protocol.
If it's the only solution, let's try do it, but this is a big change that I would prefer to avoid, because this simplifies the json encoding of each parameter, and I think there is also some default implementation applied to this protocol.
Removing it might not be easy.