- Use the new Swift 6 `@available` macro to remove requirement on
`.platform` in Package.swift.
- DRY: define the swift settings once for all in `Package.swift`
### Motivation:
- Remove the requirement to build on macOS 15 in `Package.swift`. This
allows library builders and end users to be more flexible on their
dependency requirements.
- The code is optionally compiled on macOS 15 and Linux, but SPM don't
enforce it anymore.
- Avoid repeating ourself. Be sure the same settings are applied on all
targets.
### Modifications:
- Create a `var swiftSetting: [SwiftSettings]` and reuse it for all
targets.
- Use `AvailabilityMacro=LambdaSwift 2.0:macOS 15.0`
- Add this on top of the majority struct / classes
```swift
#if swift(>=6.1)
@available(LambdaSwift 2.0, *)
#endif
```
### Result:
When using Swift 6.1, there is no more SPM dependency on macOS 15
Add a hard coded version number to the user agent string, for an
eventual identification by the Lambda service
### Motivation:
It's [an
issue](https://github.com/swift-server/swift-aws-lambda-runtime/issues/108)
that was open more than 5 years ago and was never addressed. At the
time, the consensus was to pickup a version number for the Package.swift
file and the maintainer at the time decided to wait for Swift to
implement this.
Five years later, and several major version of Swift later, this is
still not available. I decided to move on and implement a less optimal
solution. This can be replaced in the future if package version ever
becomes part of Package.swift.
### Modifications:
Add a version enum to isolate the versioning in one place. I decided to
keep it simple and not over engineering it with major, minor, patch and
pre-release. At the time, it's a simple string. This is all what we need
for usage in the user agent string.
### Result:
User agent now identifies as `Swift-Lambda/2,0` instead of
`Swift-Lambda/unknown`
The user-agent string was repeated at 5+ different places in the source
code.
I defined it as a constant in the `ControlPlaneRequest` struct where
other similar constant have been defined and make sure the rest of the
code only uses that constant.
This should address
https://github.com/swift-server/swift-aws-lambda-runtime/issues/492
Sébastien Stormacq
Fabian Fett