SwinjectAutoregistration crashes on Xcode 12.0 (12A7209)

[muratmusic]

Hello everybody,

How soon can you fix this problem? On Xcode 11.7 SwinjectAutoregistration works OK.

[ghost]

Also seeing this issue after upgrading to XCode 12

[tkohout]

Could you provide some example project which would work on Xcode 11 and fail to resolve in Xcode 12?

Or at least the autoregister calls that register the failing services.

[ghost]

Hi @tkohout, our project is confidential, so unfortunately I can only provide you modified excerpts. Hope this helps you anyway.

This is the autoregister call: container.autoregister(EnvironmentProvider.self, initializer: EnvironmentProviderImpl.init)

EnvironmentProviderImpl looks like this:

import Foundation
import Shared

public struct EnvironmentProviderImpl: EnvironmentProvider {
    private enum Paths: String {
        case imprint = "imprint"

    }

    public var supportedAppliances: [ApplianceType] = [.applX, .applY, .applZ]

    public var environment: Environment {
        #if DEV
        return .dev
        #elseif STAG
        return .stag
        #elseif LIVE
        return .live
        #endif
    }

    private var locale: String {
        Locale.current.identifier
    }
}

public extension EnvironmentProviderImpl {
    var imprintURL: URL {
        baseRedirectURL.appendingPath(Path.imprint.rawValue)
    }

}

The project compiles and runs but right at the start, we get this error:

Thanks for your help!

[tkohout]

@aknolldev Thanks for the example:

The problem is in this line:

public var supportedAppliances: [ApplianceType] = [.applX, .applY, .applZ]

If you have a struct that has a variable with a default value the compiler will create two inits, in you case it is:

.init and .init(supportedAppliances:)

For some reason, since the Swift 5.3 the compiler will pick the .init(supportedAppliances:) instead of .init which was selected in the older Swift. Swinject then tries to resolve [ApplianceType] which it can't find. Interestingly enough this will only happen if the struct has only one variable with default value. If you have e.g. 2 variables, it will work the same as in the old version.

In your case you have multiple ways to solve this error:

1. add your own empty init to your struct:

   init() {}

2. force the use of the correct init in the registration code:

   container.autoregister(EnvironmentProvider.self, initializer: EnvironmentProviderImpl.init as () -> EnvironmentProviderImpl)

3. rewrite you code not to use variable with default value

   public var supportedAppliances: [ApplianceType] { [.applX, .applY, .applZ] }

[ghost]

Thanks @tkohout! We will go for option 2, it fits best for us and works perfectly fine. 👍