Swift Generated Code: Add @unchecked Sendable conformance to classes that conform to FeatureManifestInterface

[ih-codes]

Hello! This is my first PR to your repo, I've been working on this with @issammani. The iOS team needs to update /Generated code in Firefox for iOS to solve some strict concurrency warnings inside our generated code. These warnings will become errors in Swift 6.0.

Here is the ticket on our end: FXIOS-13577

This ticket contains detailed information about the concurrency issues with screenshots of the errors we are getting.

Implementation Details

This PR adds @unchecked Sendable to Swift classes that conform to FeatureManifestInterface, which suppresses strict concurrency warnings related to non-Sendable types containing mutable state.

Using @unchecked Sendable simply maintains existing behaviour and does not change any behaviour.

While we can suppress these errors for now, ideally these FeatureManifestInterface-conforming classes should be updated in the future to be compliant with Swift Concurrency's rules for concurrency-safe code.

Followup ticket: FXIOS-13579.

Pull Request checklist

• Breaking changes: This PR follows our breaking change policy
  • This PR follows the breaking change policy:
    • This PR has no breaking API changes, or
    • There are corresponding PRs for our consumer applications that resolve the breaking changes and have been approved
• Quality: This PR builds and tests run cleanly
  • Note:
    • For changes that need extra cross-platform testing, consider adding [ci full] to the PR title.
    • If this pull request includes a breaking change, consider cutting a new release after merging.
• Tests: This PR includes thorough tests or an explanation of why it does not
• Changelog: This PR includes a changelog entry in CHANGELOG.md or an explanation of why it does not need one
  • Any breaking changes to Swift or Kotlin binding APIs are noted explicitly
• Dependencies: This PR follows our dependency management guidelines
  • Any new dependencies are accompanied by a summary of the due diligence applied in selecting them.

[skhamis]

This seems fairly low-risk since it doesn't look like the FeatureManifestInterface is adjusting any mutable state. LGTM!

Edit: btw, very exciting to see a PR coming in from firefox-ios to update some of our not-so-updated swift! Definitely is the design for the migration :)

[ih-codes]

This seems fairly low-risk since it doesn't look like the FeatureManifestInterface is adjusting any mutable state. LGTM!

Edit: btw, very exciting to see a PR coming in from firefox-ios to update some of our not-so-updated swift! Definitely is the design for the migration :)

Thanks @skhamis! I'll likely be back with some more tweaks as we work through the strict concurrency warnings on the Firefox for iOS side of things. 😁

[issammani]

@skhamis @lougeniaC64 can you please add this to the merge queue if it looks good. We don't have merge acess 😄

[issammani]

@mhammond thanks for merging. Can you please trigger a new artifact build so we can try it out today 😄

[mhammond]

/taskcluster ci full

[mhammond]

Not sure how to trigger a new artifact - I think a full CI one will generate something usable though?