wip: add an API of plugins to retrieve authentication information

Sources/Commands/Utilities/PluginDelegate.swift

@@ -322,6 +322,20 @@ final class PluginDelegate: PluginInvocationDelegate {
         }
     }
 
+    func authorizationInfoRequest(
+        for url: URL,
+        completion: @escaping (Result<PluginInvocationAuthorizationInfoResult?, Error>) -> Void
+    ) {
+        // Get the authorization info from the authorization provider
+        DispatchQueue.sharedConcurrent.async {
+            completion(Result {
+                try self.swiftTool.getAuthorizationProvider()?.authentication(for: url).map {
+                    .init(username: $0, password: $1)
+                }
+            })
+        }
+    }
+
     private func createSymbolGraphForPlugin(
         forTarget targetName: String,
         options: PluginInvocationSymbolGraphOptions

Sources/PackagePlugin/PackageManagerProxy.swift

@@ -246,6 +246,27 @@ public struct PackageManager {
         /// The directory that contains the symbol graph files for the target.
         public var directoryPath: Path
     }
+
+    /// Return authorization information for the URL.
+    // FIXME: add a hashing key
+    public func getAuthorizationInfo(
+        for url: String
+    ) throws -> AuthorizationInfo? {
+        // Ask the plugin host for authorization information, and wait for a response.
+        // FIXME: We'll want to make this asynchronous when there is back deployment support for it.
+        return try sendMessageAndWaitForReply(.authorizationInfoRequest(url: url)) {
+            guard case .authorizationInfoResponse(let result) = $0 else { return nil }
+            return result.map{ .init($0) }
+        }
+    }
+
+    /// Represents  authorization information
+    public struct AuthorizationInfo {
+        /// The username
+        public var username: String
+        /// The password
+        public var password: String
+    }
 }
 
 fileprivate extension PackageManager {
@@ -440,3 +461,10 @@ fileprivate extension PackageManager.SymbolGraphResult {
         self.directoryPath = .init(result.directoryPath)
     }
 }
+
+fileprivate extension PackageManager.AuthorizationInfo {
+    init(_ result: HostToPluginMessage.AuthorizationInfo) {
+        self.username = result.username
+        self.password = result.password
+    }
+}

Sources/PackagePlugin/PluginMessages.swift

@@ -246,7 +246,14 @@ enum HostToPluginMessage: Codable {
         struct SymbolGraphResult: Codable {
             var directoryPath: String
         }
-
+
+    /// A response to a request for authorization info
+    case authorizationInfoResponse(result: AuthorizationInfo?)
+        struct AuthorizationInfo: Codable {
+            var username: String
+            var password: String
+        }
+
     /// A response of an error while trying to complete a request.
     case errorResponse(error: String)
 }
@@ -324,4 +331,7 @@ enum PluginToHostMessage: Codable {
             var includeSPI: Bool
             var emitExtensionBlocks: Bool
         }
+
+    /// the plugin requesting authorization information
+    case authorizationInfoRequest(url: String)
 }

Sources/SPMBuildCore/Plugins/PluginInvocation.swift

@@ -259,6 +259,23 @@ extension PluginTarget {
                             self.observabilityScope.emit(debug: "couldn't send reply to plugin", underlyingError: error)
                         }
                     }
+                case .authorizationInfoRequest(let _url):
+                    guard let url = URL(string: _url) else {
+                        throw StringError("Invalid URL: \(_url)")
+                    }
+                    self.invocationDelegate.authorizationInfoRequest(for: url) {
+                        do {
+                            switch $0 {
+                            case .success(let result):
+                                responder(try HostToPluginMessage.authorizationInfoResponse(result: result.map{ .init($0) }).toData())
+                            case .failure(let error):
+                                responder(try HostToPluginMessage.errorResponse(error: String(describing: error)).toData())
+                            }
+                        }
+                        catch {
+                            self.observabilityScope.emit(debug: "couldn't send reply to plugin", underlyingError: error)
+                        }
+                    }
                 }
             }
         }
@@ -702,6 +719,9 @@ public protocol PluginInvocationDelegate {
 
     /// Called when a plugin requests that the host computes and returns symbol graph information for a particular target.
     func pluginRequestedSymbolGraph(forTarget name: String, options: PluginInvocationSymbolGraphOptions, completion: @escaping (Result<PluginInvocationSymbolGraphResult, Error>) -> Void)
+
+    /// Called when a plugin requests authorization information  through the PackagePlugin APIs.
+    func authorizationInfoRequest(for url: URL, completion: @escaping (Result<PluginInvocationAuthorizationInfoResult?, Error>) -> Void)
 }
 
 public struct PluginInvocationSymbolGraphOptions {
@@ -721,6 +741,15 @@ public struct PluginInvocationSymbolGraphResult {
     }
 }
 
+public struct PluginInvocationAuthorizationInfoResult {
+    public var username: String
+    public var password: String
+    public init(username: String, password: String) {
+        self.username = username
+        self.password = password
+    }
+}
+
 public enum PluginInvocationBuildSubset {
     case all(includingTests: Bool)
     case product(String)
@@ -829,6 +858,9 @@ public extension PluginInvocationDelegate {
     func pluginRequestedSymbolGraph(forTarget name: String, options: PluginInvocationSymbolGraphOptions, completion: @escaping (Result<PluginInvocationSymbolGraphResult, Error>) -> Void) {
         DispatchQueue.sharedConcurrent.async { completion(Result.failure(StringError("unimplemented"))) }
     }
+    func authorizationInfoRequest(for url: URL, completion: @escaping (Result<PluginInvocationAuthorizationInfoResult?, Error>) -> Void) {
+        DispatchQueue.sharedConcurrent.async { completion(Result.failure(StringError("unimplemented"))) }
+    }
 }
 
 fileprivate extension PluginInvocationBuildSubset {
@@ -999,6 +1031,13 @@ fileprivate extension HostToPluginMessage.SymbolGraphResult {
     }
 }
 
+fileprivate extension HostToPluginMessage.AuthorizationInfo {
+    init(_ result: PluginInvocationAuthorizationInfoResult) {
+        self.username = result.username
+        self.password = result.password
+    }
+}
+
 extension ObservabilityMetadata {
     public var fileLocation: FileLocation? {
         get {