Allow clients to programmatically accept an identity change

This will allow clients to take the information from specific registry error cases and programmatically accept them as valid. This can be useful if a client wants to offer a way for users to accept an allowed identity change.

Author: neonichu

Sources/PackageRegistry/RegistryClient.swift

@@ -102,6 +102,24 @@ public final class RegistryClient: Cancellable {
         try self.httpClient.cancel(deadline: deadline)
     }
 
+    public func acceptIdentityChange(
+        package: PackageIdentity.RegistryIdentity,
+        version: Version,
+        signingEntity: SigningEntity,
+        observabilityScope: ObservabilityScope,
+        callbackQueue: DispatchQueue,
+        completion: @escaping (Result<Void, Error>) -> Void
+    ) {
+        let signingEntityTOFU = PackageSigningEntityTOFU(signingEntityStorage: self.signingEntityStorage, signingEntityCheckingMode: self.signingEntityCheckingMode)
+        signingEntityTOFU.writeToStorage(
+            package: package,
+            version: version,
+            signingEntity: signingEntity,
+            observabilityScope: observabilityScope,
+            callbackQueue: callbackQueue,
+            completion: completion)
+    }
+
     public func getPackageMetadata(
         package: PackageIdentity,
         timeout: DispatchTimeInterval? = .none,

Sources/PackageRegistry/SigningEntityTOFU.swift

@@ -178,7 +178,7 @@ struct PackageSigningEntityTOFU {
         }
     }
 
-    private func writeToStorage(
+    func writeToStorage(
         package: PackageIdentity.RegistryIdentity,
         version: Version,
         signingEntity: SigningEntity,

Sources/Workspace/Workspace.swift

@@ -3402,6 +3402,24 @@ extension Workspace {
          // remove the local copy
          try registryDownloadsManager.remove(package: dependency.packageRef.identity)
      }
+
+     /// Accept an identity change that we raise a `RegistryError` for.
+     public func acceptIdentityChange(
+         package: PackageIdentity.RegistryIdentity,
+         version: Version,
+         signingEntity: SigningEntity,
+         observabilityScope: ObservabilityScope,
+         callbackQueue: DispatchQueue,
+         completion: @escaping (Result<Void, Error>) -> Void
+     ) {
+         self.registryClient.acceptIdentityChange(
+            package: package,
+            version: version,
+            signingEntity: signingEntity,
+            observabilityScope: observabilityScope,
+            callbackQueue: callbackQueue,
+            completion: completion)
+     }
  }
 
 // MARK: - Utility extensions