Finish Riley's monster commit

3b38d725d7
May the Gods have mercy on my soul.

Shared/Server Protocol/CodableError.swift

@@ -0,0 +1,249 @@
+//
+//  CodableError.swift
+//  AltKit
+//
+//  Created by Riley Testut on 3/5/20.
+//  Copyright © 2020 Riley Testut. All rights reserved.
+//
+
+import Foundation
+
+// Can only automatically conform ALTServerError.Code to Codable, not ALTServerError itself
+extension ALTServerError.Code: Codable {}
+
+private extension ErrorUserInfoKey
+{
+    static let altLocalizedDescription: String = "ALTLocalizedDescription"
+    static let altLocalizedFailureReason: String = "ALTLocalizedFailureReason"
+    static let altLocalizedRecoverySuggestion: String = "ALTLocalizedRecoverySuggestion"
+    static let altDebugDescription: String = "ALTDebugDescription"
+}
+
+extension CodableError
+{
+    enum UserInfoValue: Codable
+    {
+        case unknown
+        case string(String)
+        case number(Int)
+        case error(NSError)
+        case codableError(CodableError)
+        indirect case array([UserInfoValue])
+        indirect case dictionary([String: UserInfoValue])
+
+        var value: Any? {
+            switch self
+            {
+            case .unknown: return nil
+            case .string(let string): return string
+            case .number(let number): return number
+            case .error(let error): return error
+            case .codableError(let error): return error.error
+            case .array(let array): return array.compactMap { $0.value } // .compactMap instead of .map to ensure nil values are removed.
+            case .dictionary(let dictionary): return dictionary.compactMapValues { $0.value } // .compactMapValues instead of .mapValues to ensure nil values are removed.
+            }
+        }
+
+        var codableValue: Codable? {
+            switch self
+            {
+            case .unknown, .string, .number: return self.value as? Codable
+            case .codableError(let error): return error
+            case .error(let nsError):
+                // Ignore error because we don't want to fail completely if error contains invalid user info value.
+                let sanitizedError = nsError.sanitizedForSerialization()
+                let data = try? NSKeyedArchiver.archivedData(withRootObject: sanitizedError, requiringSecureCoding: true)
+                return data
+
+            case .array(let array): return array
+            case .dictionary(let dictionary): return dictionary
+            }
+        }
+
+        init(_ rawValue: Any?)
+        {
+            switch rawValue
+            {
+            case let string as String: self = .string(string)
+            case let number as Int: self = .number(number)
+            case let error as NSError: self = .codableError(CodableError(error: error))
+            case let array as [Any]: self = .array(array.compactMap(UserInfoValue.init))
+            case let dictionary as [String: Any]: self = .dictionary(dictionary.compactMapValues(UserInfoValue.init))
+            default: self = .unknown
+            }
+        }
+
+        init(from decoder: Decoder) throws
+        {
+            let container = try decoder.singleValueContainer()
+
+            if
+                let data = try? container.decode(Data.self),
+                let error = try? NSKeyedUnarchiver.unarchivedObject(ofClass: NSError.self, from: data)
+            {
+                self = .error(error)
+            }
+            else if let codableError = try? container.decode(CodableError.self)
+            {
+                self = .codableError(codableError)
+            }
+            else if let string = try? container.decode(String.self)
+            {
+                self = .string(string)
+            }
+            else if let number = try? container.decode(Int.self)
+            {
+                self = .number(number)
+            }
+            else if let array = try? container.decode([UserInfoValue].self)
+            {
+                self = .array(array)
+            }
+            else if let dictionary = try? container.decode([String: UserInfoValue].self)
+            {
+                self = .dictionary(dictionary)
+            }
+            else
+            {
+                self = .unknown
+            }
+        }
+
+        func encode(to encoder: Encoder) throws
+        {
+            var container = encoder.singleValueContainer()
+
+            if let value = self.codableValue
+            {
+                try container.encode(value)
+            }
+            else
+            {
+                try container.encodeNil()
+            }
+        }
+    }
+}
+
+struct CodableError: Codable
+{
+    var error: Error {
+        return self.rawError ?? NSError(domain: self.errorDomain, code: self.errorCode, userInfo: self.userInfo ?? [:])
+    }
+    private var rawError: Error?
+
+    private var errorDomain: String
+    private var errorCode: Int
+    private var userInfo: [String: Any]?
+
+    private enum CodingKeys: String, CodingKey
+    {
+        case errorDomain
+        case errorCode
+        case legacyUserInfo = "userInfo"
+        case errorUserInfo
+    }
+
+    init(error: Error)
+    {
+        self.rawError = error
+
+        let nsError = error as NSError
+        self.errorDomain = nsError.domain
+        self.errorCode = nsError.code
+
+        if !nsError.userInfo.isEmpty
+        {
+            self.userInfo = nsError.userInfo
+        }
+    }
+
+    init(from decoder: Decoder) throws
+    {
+        let container = try decoder.container(keyedBy: CodingKeys.self)
+
+        // Assume ALTServerError.errorDomain if no explicit domain provided.
+        self.errorDomain = try container.decodeIfPresent(String.self, forKey: .errorDomain) ?? ALTServerError.errorDomain
+        self.errorCode = try container.decode(Int.self, forKey: .errorCode)
+
+        if let rawUserInfo = try container.decodeIfPresent([String: UserInfoValue].self, forKey: .errorUserInfo)
+        {
+            // Attempt decoding from .errorUserInfo first, because it will gracefully handle unknown user info values.
+
+            // Copy ALTLocalized... values to NSLocalized... if provider is nil or if error is unrecognized.
+            // This ensures we preserve error messages if receiving an unknown error.
+            var userInfo = rawUserInfo.compactMapValues { $0.value }
+
+            // Recognized == the provider returns value for NSLocalizedFailureReasonErrorKey, or error is ALTServerError.underlyingError.
+            let provider = NSError.userInfoValueProvider(forDomain: self.errorDomain)
+            let isRecognizedError = (
+                provider?(self.error, NSLocalizedFailureReasonErrorKey) != nil ||
+                (self.error._domain == ALTServerError.errorDomain && self.error._code == ALTServerError.underlyingError.rawValue)
+            )
+
+            if !isRecognizedError
+            {
+                // Error not recognized, so copy over NSLocalizedDescriptionKey and NSLocalizedFailureReasonErrorKey.
+                userInfo[NSLocalizedDescriptionKey] = userInfo[ErrorUserInfoKey.altLocalizedDescription]
+                userInfo[NSLocalizedFailureReasonErrorKey] = userInfo[ErrorUserInfoKey.altLocalizedFailureReason]
+            }
+
+            // Copy over NSLocalizedRecoverySuggestionErrorKey and NSDebugDescriptionErrorKey if provider returns nil.
+            if provider?(self.error, NSLocalizedRecoverySuggestionErrorKey) == nil
+            {
+                userInfo[NSLocalizedRecoverySuggestionErrorKey] = userInfo[ErrorUserInfoKey.altLocalizedRecoverySuggestion]
+            }
+
+            if provider?(self.error, NSDebugDescriptionErrorKey) == nil
+            {
+                userInfo[NSDebugDescriptionErrorKey] = userInfo[ErrorUserInfoKey.altDebugDescription]
+            }
+
+            userInfo[ErrorUserInfoKey.altLocalizedDescription] = nil
+            userInfo[ErrorUserInfoKey.altLocalizedFailureReason] = nil
+            userInfo[ErrorUserInfoKey.altLocalizedRecoverySuggestion] = nil
+            userInfo[ErrorUserInfoKey.altDebugDescription] = nil
+
+            self.userInfo = userInfo
+        }
+        else if let rawUserInfo = try container.decodeIfPresent([String: UserInfoValue].self, forKey: .legacyUserInfo)
+        {
+            // Fall back to decoding .legacyUserInfo, which only supports String and NSError values.
+            let userInfo = rawUserInfo.compactMapValues { $0.value }
+            self.userInfo = userInfo
+        }
+    }
+
+    func encode(to encoder: Encoder) throws
+    {
+        var container = encoder.container(keyedBy: CodingKeys.self)
+        try container.encode(self.errorDomain, forKey: .errorDomain)
+        try container.encode(self.errorCode, forKey: .errorCode)
+
+        let rawLegacyUserInfo = self.userInfo?.compactMapValues { (value) -> UserInfoValue? in
+            // .legacyUserInfo only supports String and NSError values.
+            switch value
+            {
+            case let string as String: return .string(string)
+            case let error as NSError: return .error(error) // Must use .error, not .codableError for backwards compatibility.
+            default: return nil
+            }
+        }
+        try container.encodeIfPresent(rawLegacyUserInfo, forKey: .legacyUserInfo)
+
+        let nsError = self.error as NSError
+
+        var userInfo = self.userInfo ?? [:]
+        userInfo[ErrorUserInfoKey.altLocalizedDescription] = nsError.localizedDescription
+        userInfo[ErrorUserInfoKey.altLocalizedFailureReason] = nsError.localizedFailureReason
+        userInfo[ErrorUserInfoKey.altLocalizedRecoverySuggestion] = nsError.localizedRecoverySuggestion
+        userInfo[ErrorUserInfoKey.altDebugDescription] = nsError.localizedDebugDescription
+
+        // No need to use alternate key. This is a no-op if userInfo already contains localizedFailure,
+        // but it caches the UserInfoProvider value if one exists.
+        userInfo[NSLocalizedFailureErrorKey] = nsError.localizedFailure
+
+        let rawUserInfo = userInfo.compactMapValues { UserInfoValue($0) }
+        try container.encodeIfPresent(rawUserInfo, forKey: .errorUserInfo)
+    }
+}

Shared/Server Protocol/CodableServerError.swift

@@ -1,126 +0,0 @@
-//
-//  CodableServerError.swift
-//  AltKit
-//
-//  Created by Riley Testut on 3/5/20.
-//  Copyright © 2020 Riley Testut. All rights reserved.
-//
-
-import Foundation
-
-// Can only automatically conform ALTServerError.Code to Codable, not ALTServerError itself
-extension ALTServerError.Code: Codable {}
-
-extension CodableServerError
-{
-    enum UserInfoValue: Codable
-    {
-        case string(String)
-        case error(NSError)
-        
-        public init(from decoder: Decoder) throws
-        {
-            let container = try decoder.singleValueContainer()
-
-            if
-                let data = try? container.decode(Data.self),
-                let error = try? NSKeyedUnarchiver.unarchivedObject(ofClass: NSError.self, from: data)
-            {
-                self = .error(error)
-            }
-            else if let string = try? container.decode(String.self)
-            {
-                self = .string(string)
-            }
-            else
-            {
-                throw DecodingError.dataCorruptedError(in: container, debugDescription: "UserInfoValue value cannot be decoded")
-            }
-        }
-        
-        func encode(to encoder: Encoder) throws
-        {
-            var container = encoder.singleValueContainer()
-            
-            switch self
-            {
-            case .string(let string): try container.encode(string)
-            case .error(let error):
-                guard let data = try? NSKeyedArchiver.archivedData(withRootObject: error, requiringSecureCoding: true) else {
-                    let context = EncodingError.Context(codingPath: container.codingPath, debugDescription: "UserInfoValue value \(self) cannot be encoded")
-                    throw EncodingError.invalidValue(self, context)
-                }
-                
-                try container.encode(data)
-            }
-        }
-    }
-}
-
-struct CodableServerError: Codable
-{
-    var error: ALTServerError {
-        return ALTServerError(self.errorCode, userInfo: self.userInfo ?? [:])
-    }
-    
-    private var errorCode: ALTServerError.Code
-    private var userInfo: [String: Any]?
-    
-    private enum CodingKeys: String, CodingKey
-    {
-        case errorCode
-        case userInfo
-    }
-
-    init(error: ALTServerError)
-    {
-        self.errorCode = error.code
-        
-        var userInfo = error.userInfo
-        if let localizedRecoverySuggestion = (error as NSError).localizedRecoverySuggestion
-        {
-            userInfo[NSLocalizedRecoverySuggestionErrorKey] = localizedRecoverySuggestion
-        }
-        
-        if !userInfo.isEmpty
-        {
-            self.userInfo = userInfo
-        }
-    }
-    
-    init(from decoder: Decoder) throws
-    {
-        let container = try decoder.container(keyedBy: CodingKeys.self)
-        
-        let errorCode = try container.decode(Int.self, forKey: .errorCode)
-        self.errorCode = ALTServerError.Code(rawValue: errorCode) ?? .unknown
-        
-        let rawUserInfo = try container.decodeIfPresent([String: UserInfoValue].self, forKey: .userInfo)
-        
-        let userInfo = rawUserInfo?.mapValues { (value) -> Any in
-            switch value
-            {
-            case .string(let string): return string
-            case .error(let error): return error
-            }
-        }
-        self.userInfo = userInfo
-    }
-    
-    func encode(to encoder: Encoder) throws
-    {
-        var container = encoder.container(keyedBy: CodingKeys.self)
-        try container.encode(self.error.code.rawValue, forKey: .errorCode)
-        
-        let rawUserInfo = self.userInfo?.compactMapValues { (value) -> UserInfoValue? in
-            switch value
-            {
-            case let string as String: return .string(string)
-            case let error as NSError: return .error(error)
-            default: return nil
-            }
-        }
-        try container.encodeIfPresent(rawUserInfo, forKey: .userInfo)
-    }
-}
-

Shared/Server Protocol/ServerProtocol.swift

@@ -197,20 +197,20 @@ public enum ServerResponse: Decodable
 // from easily changing response format for a request in the future.
 public struct ErrorResponse: ServerMessageProtocol
 {
-    public var version = 2
+    public var version = 3
     public var identifier = "ErrorResponse"
     
     public var error: ALTServerError {
-        return self.serverError?.error ?? ALTServerError(self.errorCode)
+        return self.serverError.map { ALTServerError($0.error) } ?? ALTServerError(self.errorCode)
     }
-    private var serverError: CodableServerError?
+    private var serverError: CodableError?
     
     // Legacy (v1)
     private var errorCode: ALTServerError.Code
     
     public init(error: ALTServerError)
     {
-        self.serverError = CodableServerError(error: error)
+        self.serverError = CodableError(error: error)
         self.errorCode = error.code
     }
 }