Merge pull request #191 from writefreely/throw-keychain-errors-instead-of-crashing

Throw (and handle) Keychain error instead of crashing

Shared/Account/AccountModel.swift

@@ -6,6 +6,9 @@ enum AccountError: Error {
     case usernameNotFound
     case serverNotFound
     case invalidServerURL
+    case couldNotSaveTokenToKeychain
+    case couldNotFetchTokenFromKeychain
+    case couldNotDeleteTokenFromKeychain
 }
 
 extension AccountError: LocalizedError {
@@ -31,6 +34,21 @@ extension AccountError: LocalizedError {
                 "Please enter a valid instance domain name. It should look like \"https://example.com\" or \"write.as\".",  // swiftlint:disable:this line_length
                 comment: ""
             )
+        case .couldNotSaveTokenToKeychain:
+            return NSLocalizedString(
+                "There was a problem trying to save your access token to the device, please try logging in again.",
+                comment: ""
+            )
+        case .couldNotFetchTokenFromKeychain:
+            return NSLocalizedString(
+                "There was a problem trying to fetch your access token from the device, please try logging in again.",
+                comment: ""
+            )
+        case .couldNotDeleteTokenFromKeychain:
+            return NSLocalizedString(
+                "There was a problem trying to delete your access token from the device, please try logging out again.",
+                comment: ""
+            )
         }
     }
 }

Shared/Extensions/WriteFreelyModel+APIHandlers.swift

@@ -10,9 +10,16 @@ extension WriteFreelyModel {
             let user = try result.get()
             fetchUserCollections()
             fetchUserPosts()
-            saveTokenToKeychain(user.token, username: user.username, server: account.server)
+            do {
-            DispatchQueue.main.async {
+                try saveTokenToKeychain(user.token, username: user.username, server: account.server)
-                self.account.login(user)
+                DispatchQueue.main.async {
+                    self.account.login(user)
+                }
+            } catch {
+                DispatchQueue.main.async {
+                    self.loginErrorMessage = "There was a problem storing your access token to the Keychain."
+                    self.isPresentingLoginErrorAlert = true
+                }
             }
         } catch WFError.notFound {
             DispatchQueue.main.async {

Shared/Extensions/WriteFreelyModel+Keychain.swift

@@ -1,7 +1,14 @@
 import Foundation
 
 extension WriteFreelyModel {
-    func saveTokenToKeychain(_ token: String, username: String?, server: String) {
+
+    enum WFKeychainError: Error {
+        case saveToKeychainFailed
+        case purgeFromKeychainFailed
+        case fetchFromKeychainFailed
+    }
+
+    func saveTokenToKeychain(_ token: String, username: String?, server: String) throws {
         let query: [String: Any] = [
             kSecClass as String: kSecClassGenericPassword,
             kSecValueData as String: token.data(using: .utf8)!,
@@ -10,7 +17,7 @@ extension WriteFreelyModel {
         ]
         let status = SecItemAdd(query as CFDictionary, nil)
         guard status == errSecDuplicateItem || status == errSecSuccess else {
-            fatalError("Error storing in Keychain with OSStatus: \(status)")
+            throw WFKeychainError.saveToKeychainFailed
         }
     }
 
@@ -22,11 +29,11 @@ extension WriteFreelyModel {
         ]
         let status = SecItemDelete(query as CFDictionary)
         guard status == errSecSuccess || status == errSecItemNotFound else {
-            fatalError("Error deleting from Keychain with OSStatus: \(status)")
+            throw WFKeychainError.purgeFromKeychainFailed
         }
     }
 
-    func fetchTokenFromKeychain(username: String?, server: String) -> String? {
+    func fetchTokenFromKeychain(username: String?, server: String) throws -> String? {
         let query: [String: Any] = [
             kSecClass as String: kSecClassGenericPassword,
             kSecAttrAccount as String: username ?? "anonymous",
@@ -41,7 +48,7 @@ extension WriteFreelyModel {
             return nil
         }
         guard status == errSecSuccess else {
-            fatalError("Error fetching from Keychain with OSStatus: \(status)")
+            throw WFKeychainError.fetchFromKeychainFailed
         }
         guard let existingSecItem = secItem as? [String: Any],
               let tokenData = existingSecItem[kSecValueData as String] as? Data,
@@ -50,4 +57,5 @@ extension WriteFreelyModel {
         }
         return token
     }
+
 }

Shared/Models/WriteFreelyModel.swift

@@ -51,18 +51,25 @@ final class WriteFreelyModel: ObservableObject {
                     print("Server URL not found")
                     return
                 }
-                guard let token = self.fetchTokenFromKeychain(
+                do {
-                        username: self.account.username,
+                    guard let token = try self.fetchTokenFromKeychain(
-                        server: self.account.server
+                            username: self.account.username,
-                ) else {
+                            server: self.account.server
-                    print("Could not fetch token from Keychain")
+                    ) else {
-                    return
+                        self.loginErrorMessage = AccountError.couldNotFetchTokenFromKeychain.localizedDescription
+                        self.isPresentingLoginErrorAlert = true
+                        return
+                    }
+
+                    self.account.login(WFUser(token: token, username: self.account.username))
+                    self.client = WFClient(for: serverURL)
+                    self.client?.user = self.account.user
+                    self.fetchUserCollections()
+                    self.fetchUserPosts()
+                } catch {
+                    self.loginErrorMessage = AccountError.couldNotFetchTokenFromKeychain.localizedDescription
+                    self.isPresentingLoginErrorAlert = true
                 }
-                self.account.login(WFUser(token: token, username: self.account.username))
-                self.client = WFClient(for: serverURL)
-                self.client?.user = self.account.user
-                self.fetchUserCollections()
-                self.fetchUserPosts()
             }
         }
 

WriteFreely-MultiPlatform.xcodeproj/project.pbxproj

@@ -969,7 +969,7 @@
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = AccentColor;
 				CODE_SIGN_STYLE = Automatic;
-				CURRENT_PROJECT_VERSION = 612;
+				CURRENT_PROJECT_VERSION = 615;
 				DEVELOPMENT_TEAM = TPPAB4YBA6;
 				ENABLE_PREVIEWS = YES;
 				INFOPLIST_FILE = iOS/Info.plist;
@@ -978,7 +978,7 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				MARKETING_VERSION = 1.0.6;
+				MARKETING_VERSION = 1.0.7;
 				PRODUCT_BUNDLE_IDENTIFIER = "com.abunchtell.WriteFreely-MultiPlatform";
 				PRODUCT_NAME = "WriteFreely-MultiPlatform";
 				SDKROOT = iphoneos;
@@ -993,7 +993,7 @@
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = AccentColor;
 				CODE_SIGN_STYLE = Automatic;
-				CURRENT_PROJECT_VERSION = 612;
+				CURRENT_PROJECT_VERSION = 615;
 				DEVELOPMENT_TEAM = TPPAB4YBA6;
 				ENABLE_PREVIEWS = YES;
 				INFOPLIST_FILE = iOS/Info.plist;
@@ -1002,7 +1002,7 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				MARKETING_VERSION = 1.0.6;
+				MARKETING_VERSION = 1.0.7;
 				PRODUCT_BUNDLE_IDENTIFIER = "com.abunchtell.WriteFreely-MultiPlatform";
 				PRODUCT_NAME = "WriteFreely-MultiPlatform";
 				SDKROOT = iphoneos;