fix(auth): parse and surface returned subscription @auth errors

When a subscription fails due to an authorization issue, parse and surface AppSyncJSONValue errors
in order to let DataStore recover

AmplifyPlugins/API/APICategoryPlugin.xcodeproj/project.pbxproj

@@ -94,6 +94,7 @@
 		6B33896E23AABEEE00561E5B /* MockReachability.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6B33896D23AABEEE00561E5B /* MockReachability.swift */; };
 		6B33897023AABF1800561E5B /* NetworkReachability.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6B33896F23AABF1800561E5B /* NetworkReachability.swift */; };
 		6B33897223AAD94800561E5B /* AWSAPIPlugin+Reachability.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6B33897123AAD94800561E5B /* AWSAPIPlugin+Reachability.swift */; };
+		7632AD8A252E1E10009B5BC9 /* AppSyncJSONValue+toJSONValue.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7632AD89252E1E10009B5BC9 /* AppSyncJSONValue+toJSONValue.swift */; };
 		9B13EA5E48896E8B38883633 /* Pods_HostApp.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 930DD773E0FB4047393CA2AD /* Pods_HostApp.framework */; };
 		A04815BCD5F9181C8AEDEF43 /* Pods_AWSAPICategoryPlugin.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 881AB4B98B48235DEC7754C2 /* Pods_AWSAPICategoryPlugin.framework */; };
 		B1F5048F35638D3D142C4F1F /* Pods_AWSAPICategoryPlugin_AWSAPICategoryPluginTests.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 1B13CFC866A30622EDD91AF4 /* Pods_AWSAPICategoryPlugin_AWSAPICategoryPluginTests.framework */; };
@@ -386,6 +387,7 @@
 		6B33897123AAD94800561E5B /* AWSAPIPlugin+Reachability.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "AWSAPIPlugin+Reachability.swift"; sourceTree = "<group>"; };
 		6DD6386039136045F18D44AC /* Pods_HostApp_AWSAPICategoryPluginTestCommon_RESTWithUserPoolIntegrationTests.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = Pods_HostApp_AWSAPICategoryPluginTestCommon_RESTWithUserPoolIntegrationTests.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		74EDB7008F5342ED4B38C9CA /* Pods_HostApp_AWSAPICategoryPluginIntegrationTests.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = Pods_HostApp_AWSAPICategoryPluginIntegrationTests.framework; sourceTree = BUILT_PRODUCTS_DIR; };
+		7632AD89252E1E10009B5BC9 /* AppSyncJSONValue+toJSONValue.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = "AppSyncJSONValue+toJSONValue.swift"; sourceTree = "<group>"; };
 		77792DD821FC754D857FC63C /* Pods-HostApp-AWSAPICategoryPluginTestCommon-GraphQLWithIAMIntegrationTests.release.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-HostApp-AWSAPICategoryPluginTestCommon-GraphQLWithIAMIntegrationTests.release.xcconfig"; path = "Target Support Files/Pods-HostApp-AWSAPICategoryPluginTestCommon-GraphQLWithIAMIntegrationTests/Pods-HostApp-AWSAPICategoryPluginTestCommon-GraphQLWithIAMIntegrationTests.release.xcconfig"; sourceTree = "<group>"; };
 		7866FCFB5807C2D20219CEBE /* Pods-HostApp-AWSAPICategoryPluginTestCommon-RESTWithIAMIntegrationTests.release.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-HostApp-AWSAPICategoryPluginTestCommon-RESTWithIAMIntegrationTests.release.xcconfig"; path = "Target Support Files/Pods-HostApp-AWSAPICategoryPluginTestCommon-RESTWithIAMIntegrationTests/Pods-HostApp-AWSAPICategoryPluginTestCommon-RESTWithIAMIntegrationTests.release.xcconfig"; sourceTree = "<group>"; };
 		7A255F655FE0AE43E68F2972 /* Pods-HostApp-AWSAPICategoryPluginTestCommon-GraphQLWithUserPoolIntegrationTests.debug.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-HostApp-AWSAPICategoryPluginTestCommon-GraphQLWithUserPoolIntegrationTests.debug.xcconfig"; path = "Target Support Files/Pods-HostApp-AWSAPICategoryPluginTestCommon-GraphQLWithUserPoolIntegrationTests/Pods-HostApp-AWSAPICategoryPluginTestCommon-GraphQLWithUserPoolIntegrationTests.debug.xcconfig"; sourceTree = "<group>"; };
@@ -820,6 +822,7 @@
 		21D7A0C6237B54D90057D00D /* Utils */ = {
 			isa = PBXGroup;
 			children = (
+				7632AD89252E1E10009B5BC9 /* AppSyncJSONValue+toJSONValue.swift */,
 				2129BE3D239486D2006363A1 /* AnyModel+JSONInit.swift */,
 				21D7A0CC237B54D90057D00D /* APIError+DecodingError.swift */,
 				21D7A0CF237B54D90057D00D /* GraphQLOperationRequest+Validate.swift */,
@@ -2168,6 +2171,7 @@
 				21D38B9B240C517C00EC2A8D /* AWSOIDCAuthProvider.swift in Sources */,
 				21D7A112237B54D90057D00D /* GraphQLOperationRequestUtils+Validator.swift in Sources */,
 				21D7A0FC237B54D90057D00D /* URLSessionFactory.swift in Sources */,
+				7632AD8A252E1E10009B5BC9 /* AppSyncJSONValue+toJSONValue.swift in Sources */,
 				21D7A103237B54D90057D00D /* URLRequestConstants.swift in Sources */,
 				21D7A118237B54D90057D00D /* APIKeyURLRequestInterceptor.swift in Sources */,
 				21D7A116237B54D90057D00D /* AWSAPIPlugin+URLSessionBehaviorDelegate.swift in Sources */,

AmplifyPlugins/API/AWSAPICategoryPlugin/Operation/AWSGraphQLSubscriptionOperation.swift

@@ -110,8 +110,7 @@ final public class AWSGraphQLSubscriptionOperation<R: Decodable>: GraphQLSubscri
         case .data(let data):
             onGraphQLResponseData(data)
         case .failed(let error):
-            dispatch(result: .failure(APIError.operationError("subscription item event failed with error", "", error)))
-            finish()
+            onSubscriptionFailure(error)
         }
     }
 
@@ -161,4 +160,27 @@ final public class AWSGraphQLSubscriptionOperation<R: Decodable>: GraphQLSubscri
         }
     }
 
+    private func onSubscriptionFailure(_ error: Error) {
+        let errorDescription = "Subscription item event failed with error"
+        guard case let ConnectionProviderError.subscription(_, payload) = error,
+              let errors = payload?["errors"] as? AppSyncJSONValue else {
+            dispatch(result: .failure(APIError.operationError(errorDescription, "", error)))
+            finish()
+            return
+        }
+
+        if let graphQLErrors = try? GraphQLResponseDecoder.decodeAppSyncErrors(errors),
+           let extensions = graphQLErrors.first?.extensions,
+           let recoveryMessage = graphQLErrors.first?.message,
+           case let .string(errorTypeValue) = extensions["errorType"] {
+                let appSyncError = AppSyncErrorType(errorTypeValue)
+                dispatch(result: .failure(APIError.operationError(errorDescription, recoveryMessage, appSyncError)))
+                finish()
+                return
+        }
+
+        dispatch(result: .failure(APIError.operationError(errorDescription, "", error)))
+        finish()
+    }
+
 }

AmplifyPlugins/API/AWSAPICategoryPlugin/Support/Utils/AppSyncJSONValue+toJSONValue.swift

@@ -0,0 +1,32 @@
+//
+// Copyright 2018-2020 Amazon.com,
+// Inc. or its affiliates. All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+import Foundation
+import Amplify
+import AppSyncRealTimeClient
+
+extension AppSyncJSONValue {
+    static func toJSONValue(_ json: AppSyncJSONValue) -> JSONValue {
+        switch json {
+        case .array(let values):
+            return JSONValue.array(values.map(AppSyncJSONValue.toJSONValue))
+        case .boolean(let value):
+            return JSONValue.boolean(value)
+        case .null:
+            return JSONValue.null
+        case .number(let value):
+            return JSONValue.number(value)
+        case .object(let content):
+            return JSONValue.object(content.reduce(into: [:]) { acc, partial in
+                let (key, value) = partial
+                acc[key] = AppSyncJSONValue.toJSONValue(value)
+            })
+        case .string(let value):
+            return JSONValue.string(value)
+        }
+    }
+}

AmplifyPlugins/API/AWSAPICategoryPlugin/Support/Utils/GraphQLResponseDecoder+DecodeError.swift

@@ -7,6 +7,7 @@
 
 import Foundation
 import Amplify
+import AppSyncRealTimeClient
 
 extension GraphQLResponseDecoder {
 
@@ -29,6 +30,20 @@ extension GraphQLResponseDecoder {
         return responseErrors
     }
 
+    static func decodeAppSyncErrors(_ appSyncJSON: AppSyncJSONValue?) throws -> [GraphQLError] {
+        guard let errorResponse = appSyncJSON else {
+            throw APIError.unknown("""
+                Unexpected failure while decoding GraphQL response containing errors:
+                \(String(describing: appSyncJSON))
+                """, "", nil)
+        }
+        guard case let .array(errors) = errorResponse else {
+            throw APIError.unknown("Expected 'errors' field not found in \(String(describing: appSyncJSON))", "", nil)
+        }
+        let convertedValues = errors.map(AppSyncJSONValue.toJSONValue)
+        return try GraphQLResponseDecoder.decodeErrors(graphQLErrors: convertedValues)
+    }
+
     static func decode(graphQLErrorJSON: JSONValue) throws -> GraphQLError {
         let serializedJSON = try JSONEncoder().encode(graphQLErrorJSON)
         let decoder = JSONDecoder()

AmplifyPlugins/Core/AWSPluginsCore/API/AppSyncErrorType.swift

@@ -8,17 +8,20 @@
 import Foundation
 
 /// Common AppSync error types
-public enum AppSyncErrorType: Equatable {
+public enum AppSyncErrorType: Equatable, Error {
 
     private static let conditionalCheckFailedErrorString = "ConditionalCheckFailedException"
     private static let conflictUnhandledErrorString = "ConflictUnhandled"
+    private static let unauthorizedErrorString = "Unauthorized"
 
     /// Conflict detection finds a version mismatch and the conflict handler rejects the mutation.
     /// See https://docs.aws.amazon.com/appsync/latest/devguide/conflict-detection-and-sync.html for more information
     case conflictUnhandled
 
     case conditionalCheck
 
+    case unauthorized
+
     case unknown(String)
 
     public init(_ value: String) {
@@ -27,6 +30,8 @@ public enum AppSyncErrorType: Equatable {
             self = .conditionalCheck
         case AppSyncErrorType.conflictUnhandledErrorString:
             self = .conflictUnhandled
+        case AppSyncErrorType.unauthorizedErrorString:
+            self = .unauthorized
         default:
             self = .unknown(value)
         }
@@ -38,6 +43,8 @@ public enum AppSyncErrorType: Equatable {
             return AppSyncErrorType.conditionalCheckFailedErrorString
         case .conflictUnhandled:
             return AppSyncErrorType.conflictUnhandledErrorString
+        case .unauthorized:
+            return AppSyncErrorType.unauthorizedErrorString
         case .unknown(let value):
             return value
         }

AmplifyPlugins/DataStore/AWSDataStoreCategoryPlugin/Sync/MutationSync/OutgoingMutationQueue/ProcessMutationErrorFromCloudOperation.swift

@@ -88,6 +88,10 @@ class ProcessMutationErrorFromCloudOperation: AsynchronousOperation {
                 finish(result: .success(nil))
             case .conflictUnhandled:
                 processConflictUnhandled(extensions)
+            case .unauthorized:
+                // TODO: dispatch Hub event
+                log.debug("Unauthorized mutation \(errorType)")
+                finish(result: .success(nil))
             case .unknown(let errorType):
                 log.debug("Unhandled error with errorType \(errorType)")
                 finish(result: .success(nil))