Add a mechanism to generate Identifiable conformance when types include an id property

[edorphy]

Motivation

I'm using this project to generate client and types for the App Store Connect API.

Every single object type from the API includes an ID property. When rendering results in SwiftUI, ForEach is our friend, but, the types are not identifiable by default. I have to create a conformance to Identifiable for everything by hand.

Proposed solution

Provide a configuration option to allow a type to add Identifiable conformance in the generated code if it includes an id property with a supported Identifiable type.

This is supported by the CreateAPI tool and would be a good feature to replicate. I want to move to as little modifications as possible.

Alternatives considered

Do things by hand and type this out. I'm only using a subset of the API and I still probably missed types that should conform.

extension Components.Schemas.AgeRatingDeclaration: Identifiable { }

extension Components.Schemas.AlternativeDistributionPackage: Identifiable { }

extension Components.Schemas.AppClipDefaultExperience: Identifiable { }

extension Components.Schemas.AppClip: Identifiable { }

extension Components.Schemas.AppCustomProductPage: Identifiable { }

extension Components.Schemas.AppEncryptionDeclaration: Identifiable { }

extension Components.Schemas.AppEvent: Identifiable { }

extension Components.Schemas.AppInfo: Identifiable { }

extension Components.Schemas.AppPreviewSet: Identifiable { }

extension Components.Schemas.AppScreenshotSet: Identifiable { }

extension Components.Schemas.AppStoreReviewDetail: Identifiable { }

extension Components.Schemas.AppStoreVersionExperimentV2: Identifiable { }

extension Components.Schemas.AppStoreVersionLocalization: Identifiable { }

extension Components.Schemas.AppStoreVersionPhasedRelease: Identifiable { }

extension Components.Schemas.AppStoreVersion: Identifiable { }

extension Components.Schemas.App: Identifiable { }

extension Components.Schemas.BetaAppLocalization: Identifiable { }

extension Components.Schemas.BetaAppReviewDetail: Identifiable { }

extension Components.Schemas.BetaAppReviewSubmission: Identifiable { }

extension Components.Schemas.BetaBuildLocalization: Identifiable { }

extension Components.Schemas.BetaCrashLog: Identifiable { }

extension Components.Schemas.BetaFeedbackCrashSubmission: Identifiable { }

extension Components.Schemas.BetaFeedbackScreenshotSubmission: Identifiable { }

extension Components.Schemas.BetaGroup: Identifiable { }

extension Components.Schemas.BetaLicenseAgreement: Identifiable { }

extension Components.Schemas.BetaTester: Identifiable { }

extension Components.Schemas.BuildBetaDetail: Identifiable { }

extension Components.Schemas.BuildBundle: Identifiable { }

extension Components.Schemas.BuildIcon: Identifiable { }

extension Components.Schemas.Build: Identifiable { }

extension Components.Schemas.BundleId: Identifiable { }

extension Components.Schemas.CiArtifact: Identifiable { }

extension Components.Schemas.CiBuildAction: Identifiable { }

extension Components.Schemas.CiBuildRun: Identifiable { }

extension Components.Schemas.CiMacOsVersion: Identifiable { }

extension Components.Schemas.CiProduct: Identifiable { }

extension Components.Schemas.CiWorkflow: Identifiable { }

extension Components.Schemas.CiXcodeVersion: Identifiable { }

extension Components.Schemas.EndUserLicenseAgreement: Identifiable { }

extension Components.Schemas.GameCenterAppVersion: Identifiable { }

extension Components.Schemas.GameCenterDetail: Identifiable { }

extension Components.Schemas.InAppPurchaseV2: Identifiable { }

extension Components.Schemas.PrereleaseVersion: Identifiable { }

extension Components.Schemas.PromotedPurchase: Identifiable { }

extension Components.Schemas.ReviewSubmission: Identifiable { }

extension Components.Schemas.RoutingAppCoverage: Identifiable { }

extension Components.Schemas.ScmGitReference: Identifiable { }

extension Components.Schemas.ScmPullRequest: Identifiable { }

extension Components.Schemas.SubscriptionGracePeriod: Identifiable { }

extension Components.Schemas.SubscriptionGroup: Identifiable { }

extension Components.Schemas.User: Identifiable { }

Additional information

See CreateAPI and Swift Lee utilizing it in another App Store Connect client codebase:

• https://github.com/CreateAPI/CreateAPI/blob/main/Docs/ConfigOptions.md#entitiesincludeidentifiableconformance
• https://github.com/AvdLee/appstoreconnect-swift-sdk/blob/master/Sources/OpenAPI/create-api.yml#L44

[czechboy0]

Hi @edorphy,

we've had similar requests in the past for generating additional conformances, but since Swift macros came around, we've been considering adding support for generating macro annotations instead, letting adopters bring the macro implementation instead. Tracked by #383, would that work for you, if implemented?

An even more powerful solution would be to implement a build plugin that would use Swift Syntax to generate the conformances you outlined in a separate file, emitted by your custom build plugin. Then, anyone who wants to adopt this feature, would just add a reference to the build plugin right after the Swift OpenAPI Generator plugin, as build plugins can see files generated by previous build plugins on the same target. That would give you maximum flexibility and allow you to more easily share your implementation with the community, as a separate package.