DataStore.save() with condition (#355)

* Adding condition to save()

* Adding condition to save()

* Add predicate to mutation event

* QueryPredicate Codable conformance

* add ingestor disposition logic

* test for conditional request failed

* Add ProcessMutationErrorFromCloudOperation to check when there is a successful responnse with graphql errors. If the graphQL error is conditional failed, then retrieve the latest remote model, and apply it to local storage.

* Adding simple AnyQueryPredicate test

* - Moved delete mutation event out of SyncMutationToCloudOperation to after possibly exeuction of ProcessMutationErrorFromCloudOperation.
- Added unit test for ProcessMutationErrorFromCloudOperation

* Add E2E test for conditional save failed

* minor changes
- AnyModelTester class rename
- unit test parallelization fix
- add correct error from StorageEngine for save()

* Removed Codable conformance for QueryPredicate and serialize graphQL version of QueryPredicate into JSON string

* remove fetch and save when processing conditional save failed

* clean up, api tests, plugin core tests

* minor comment update

* Code clean up - use GraphQLFilter typealias, 'JSON' casing, DataStore error naming, removed QueryPredicateInput, updated MutationEvent's field as graphQLFiilterJSON

* rename parameter to `filter`

* Move GraphQLFilter serialization under GraphQLFilterConverter

Amplify.xcodeproj/project.pbxproj

@@ -44,11 +44,12 @@
 		212CE70523E9E967007D8E71 /* GraphQLQuery.swift in Sources */ = {isa = PBXBuildFile; fileRef = 212CE70223E9E967007D8E71 /* GraphQLQuery.swift */; };
 		212CE70B23E9E991007D8E71 /* ModelIdDecorator.swift in Sources */ = {isa = PBXBuildFile; fileRef = 212CE70623E9E990007D8E71 /* ModelIdDecorator.swift */; };
 		212CE70C23E9E991007D8E71 /* ConflictResolutionDecorator.swift in Sources */ = {isa = PBXBuildFile; fileRef = 212CE70723E9E990007D8E71 /* ConflictResolutionDecorator.swift */; };
-		212CE70D23E9E991007D8E71 /* PredicateDecorator.swift in Sources */ = {isa = PBXBuildFile; fileRef = 212CE70823E9E990007D8E71 /* PredicateDecorator.swift */; };
+		212CE70D23E9E991007D8E71 /* FilterDecorator.swift in Sources */ = {isa = PBXBuildFile; fileRef = 212CE70823E9E990007D8E71 /* FilterDecorator.swift */; };
 		212CE70E23E9E991007D8E71 /* PaginationDecorator.swift in Sources */ = {isa = PBXBuildFile; fileRef = 212CE70923E9E991007D8E71 /* PaginationDecorator.swift */; };
 		212CE70F23E9E991007D8E71 /* ModelDecorator.swift in Sources */ = {isa = PBXBuildFile; fileRef = 212CE70A23E9E991007D8E71 /* ModelDecorator.swift */; };
 		212CE71123E9EA6A007D8E71 /* ModelField+GraphQL.swift in Sources */ = {isa = PBXBuildFile; fileRef = 212CE71023E9EA6A007D8E71 /* ModelField+GraphQL.swift */; };
 		212CE71323E9F2ED007D8E71 /* DirectiveNameDecorator.swift in Sources */ = {isa = PBXBuildFile; fileRef = 212CE71223E9F2ED007D8E71 /* DirectiveNameDecorator.swift */; };
+		213481D9242AFA62001966DE /* AnyModelTester.swift in Sources */ = {isa = PBXBuildFile; fileRef = 213481D8242AFA62001966DE /* AnyModelTester.swift */; };
 		21409C552384C55D000A53C9 /* LabelType.swift in Sources */ = {isa = PBXBuildFile; fileRef = 21409C542384C55D000A53C9 /* LabelType.swift */; };
 		21409C5A2384C57D000A53C9 /* GraphQLMutationType.swift in Sources */ = {isa = PBXBuildFile; fileRef = 21409C572384C57D000A53C9 /* GraphQLMutationType.swift */; };
 		21409C5B2384C57D000A53C9 /* GraphQLQueryType.swift in Sources */ = {isa = PBXBuildFile; fileRef = 21409C582384C57D000A53C9 /* GraphQLQueryType.swift */; };
@@ -568,7 +569,7 @@
 		212CE70223E9E967007D8E71 /* GraphQLQuery.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = GraphQLQuery.swift; sourceTree = "<group>"; };
 		212CE70623E9E990007D8E71 /* ModelIdDecorator.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = ModelIdDecorator.swift; sourceTree = "<group>"; };
 		212CE70723E9E990007D8E71 /* ConflictResolutionDecorator.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = ConflictResolutionDecorator.swift; sourceTree = "<group>"; };
-		212CE70823E9E990007D8E71 /* PredicateDecorator.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = PredicateDecorator.swift; sourceTree = "<group>"; };
+		212CE70823E9E990007D8E71 /* FilterDecorator.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = FilterDecorator.swift; sourceTree = "<group>"; };
 		212CE70923E9E991007D8E71 /* PaginationDecorator.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = PaginationDecorator.swift; sourceTree = "<group>"; };
 		212CE70A23E9E991007D8E71 /* ModelDecorator.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = ModelDecorator.swift; sourceTree = "<group>"; };
 		212CE71023E9EA6A007D8E71 /* ModelField+GraphQL.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "ModelField+GraphQL.swift"; sourceTree = "<group>"; };
@@ -580,6 +581,7 @@
 		212CE71B23EA1847007D8E71 /* GraphQLListQueryTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = GraphQLListQueryTests.swift; sourceTree = "<group>"; };
 		212CE71C23EA1847007D8E71 /* GraphQLSyncQueryTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = GraphQLSyncQueryTests.swift; sourceTree = "<group>"; };
 		212CE72023EA184F007D8E71 /* GraphQLSubscriptionTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = GraphQLSubscriptionTests.swift; sourceTree = "<group>"; };
+		213481D8242AFA62001966DE /* AnyModelTester.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AnyModelTester.swift; sourceTree = "<group>"; };
 		21409C4C23847E41000A53C9 /* LabelType.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = LabelType.swift; sourceTree = "<group>"; };
 		21409C542384C55D000A53C9 /* LabelType.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = LabelType.swift; sourceTree = "<group>"; };
 		21409C572384C57D000A53C9 /* GraphQLMutationType.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = GraphQLMutationType.swift; sourceTree = "<group>"; };
@@ -1338,11 +1340,19 @@
 				212CE70A23E9E991007D8E71 /* ModelDecorator.swift */,
 				212CE70623E9E990007D8E71 /* ModelIdDecorator.swift */,
 				212CE70923E9E991007D8E71 /* PaginationDecorator.swift */,
-				212CE70823E9E990007D8E71 /* PredicateDecorator.swift */,
+				212CE70823E9E990007D8E71 /* FilterDecorator.swift */,
 			);
 			path = Decorator;
 			sourceTree = "<group>";
 		};
+		213481D7242AFA58001966DE /* Support */ = {
+			isa = PBXGroup;
+			children = (
+				213481D8242AFA62001966DE /* AnyModelTester.swift */,
+			);
+			path = Support;
+			sourceTree = "<group>";
+		};
 		21409C562384C57D000A53C9 /* GraphQL */ = {
 			isa = PBXGroup;
 			children = (
@@ -2574,10 +2584,11 @@
 		FAD3937B23820CE200463F5E /* DataStore */ = {
 			isa = PBXGroup;
 			children = (
+				213481D7242AFA58001966DE /* Support */,
 				FA8EE772238621320097E4F1 /* AnyModelTests.swift */,
-				FAE414602399A6A500CE94C2 /* ModelRegistryTests.swift */,
 				FAD3937923820CDB00463F5E /* DataStoreCategoryClientAPITests.swift */,
 				FAD3937C23820D0200463F5E /* DataStoreCategoryConfigurationTests.swift */,
+				FAE414602399A6A500CE94C2 /* ModelRegistryTests.swift */,
 			);
 			path = DataStore;
 			sourceTree = "<group>";
@@ -3482,7 +3493,7 @@
 				21420A91237222A900FA140C /* AWSAuthorizationConfiguration.swift in Sources */,
 				212CE70F23E9E991007D8E71 /* ModelDecorator.swift in Sources */,
 				21420A97237222A900FA140C /* IAMCredentialProvider.swift in Sources */,
-				212CE70D23E9E991007D8E71 /* PredicateDecorator.swift in Sources */,
+				212CE70D23E9E991007D8E71 /* FilterDecorator.swift in Sources */,
 				219A888123EB629800BBC5F2 /* ModelBasedGraphQLDocumentDecorator.swift in Sources */,
 				212CE70423E9E967007D8E71 /* GraphQLSubscription.swift in Sources */,
 				21420A99237222A900FA140C /* APIKeyProvider.swift in Sources */,
@@ -3829,6 +3840,7 @@
 				FA47B8362350C2D60031A0E3 /* AutoUnsubscribeOperationTests.swift in Sources */,
 				FAC2356E227A056600424678 /* AnalyticsCategoryClientAPITests.swift in Sources */,
 				B4BD6B3323708C0000A1F0A7 /* PredictionsCategoryClientAPITests.swift in Sources */,
+				213481D9242AFA62001966DE /* AnyModelTester.swift in Sources */,
 				FA47B8382350C58B0031A0E3 /* AutoUnsubscribeHubListenToOperationTests.swift in Sources */,
 				FAC23574227A056B00424678 /* ConfigurationTests.swift in Sources */,
 				B9DCA263240F217C00075E22 /* AnyEncodableTests.swift in Sources */,

Amplify/Categories/DataStore/DataStoreCategory+Behavior.swift

@@ -6,8 +6,10 @@
 //
 
 extension DataStoreCategory: DataStoreBaseBehavior {
-    public func save<M: Model>(_ model: M, completion: @escaping DataStoreCallback<M>) {
-        plugin.save(model, completion: completion)
+    public func save<M: Model>(_ model: M,
+                               where condition: QueryPredicate? = nil,
+                               completion: @escaping DataStoreCallback<M>) {
+        plugin.save(model, where: condition, completion: completion)
     }
 
     public func query<M: Model>(_ modelType: M.Type,

Amplify/Categories/DataStore/DataStoreCategory+HubPayloadEventName.swift

@@ -19,4 +19,8 @@ public extension HubPayload.EventName.DataStore {
     /// who are interested in model updates must be notified in any case of a sync received. The HubPayload will be a
     /// `MutationEvent` instance containing the newly mutated data from the remote API.
     static let syncReceived = "DataStore.syncReceived"
+
+    /// Dispatched when DataStore receives a sync response from the remote API via the API category. The Hub Payload
+    /// will be a `MutationEvent` instance that caused the conditional save failed.
+    static let conditionalSaveFailed = "DataStore.conditionalSaveFailed"
 }

Amplify/Categories/DataStore/DataStoreCategoryBehavior.swift

@@ -15,6 +15,7 @@ public protocol DataStoreBaseBehavior {
 
     /// Saves the model to storage. If sync is enabled, also initiates a sync of the mutation to the remote API
     func save<M: Model>(_ model: M,
+                        where condition: QueryPredicate?,
                         completion: @escaping DataStoreCallback<M>)
 
     func query<M: Model>(_ modelType: M.Type,

Amplify/Categories/DataStore/DataStoreError.swift

@@ -13,6 +13,7 @@ public enum DataStoreError: Error {
     case api(AmplifyError)
     case configuration(ErrorDescription, RecoverySuggestion, Error? = nil)
     case conflict(DataStoreSyncConflict)
+    case invalidCondition(ErrorDescription, RecoverySuggestion, Error? = nil)
     case decodingError(ErrorDescription, RecoverySuggestion)
     case internalOperation(ErrorDescription, RecoverySuggestion, Error? = nil)
     case invalidDatabase(path: String, Error? = nil)
@@ -45,6 +46,7 @@ extension DataStoreError: AmplifyError {
             Only a single result was expected and the actual count was \(count).
             """
         case .configuration(let errorDescription, _, _),
+             .invalidCondition(let errorDescription, _, _),
              .decodingError(let errorDescription, _),
              .internalOperation(let errorDescription, _, _),
              .sync(let errorDescription, _, _),
@@ -72,6 +74,7 @@ extension DataStoreError: AmplifyError {
             as unique indexes and primary keys.
             """
         case .configuration(_, let recoverySuggestion, _),
+             .invalidCondition(_, let recoverySuggestion, _),
              .decodingError(_, let recoverySuggestion),
              .internalOperation(_, let recoverySuggestion, _),
              .sync(_, let recoverySuggestion, _),
@@ -85,6 +88,7 @@ extension DataStoreError: AmplifyError {
         case .api(let amplifyError):
             return amplifyError
         case .configuration(_, _, let underlyingError),
+             .invalidCondition(_, _, let underlyingError),
              .internalOperation(_, _, let underlyingError),
              .invalidDatabase(_, let underlyingError),
              .invalidOperation(let underlyingError),

Amplify/Categories/DataStore/Query/QueryPredicate.swift

@@ -31,7 +31,6 @@ public enum QueryPredicateConstant: QueryPredicate {
 }
 
 public class QueryPredicateGroup: QueryPredicate {
-
     public internal(set) var type: QueryPredicateGroupType
     public internal(set) var predicates: [QueryPredicate]
 

Amplify/Categories/DataStore/Subscribe/MutationEvent+Schema.swift

@@ -17,6 +17,7 @@ extension MutationEvent {
         case createdAt
         case version
         case inProcess
+        case graphQLFilterJSON
     }
 
     public static let keys = CodingKeys.self
@@ -37,7 +38,8 @@ extension MutationEvent {
             .field(mutation.mutationType, is: .required, ofType: .string),
             .field(mutation.createdAt, is: .required, ofType: .dateTime),
             .field(mutation.version, is: .optional, ofType: .int),
-            .field(mutation.inProcess, is: .optional, ofType: .bool)
+            .field(mutation.inProcess, is: .required, ofType: .bool),
+            .field(mutation.graphQLFilterJSON, is: .optional, ofType: .string)
         )
     }
 }

Amplify/Categories/DataStore/Subscribe/MutationEvent.swift

@@ -16,6 +16,7 @@ public struct MutationEvent: Model {
     public var createdAt: Date
     public var version: Int?
     public var inProcess: Bool
+    public var graphQLFilterJSON: String?
 
     public init(id: Identifier = UUID().uuidString,
                 modelId: String,
@@ -24,7 +25,8 @@ public struct MutationEvent: Model {
                 mutationType: MutationType,
                 createdAt: Date = Date(),
                 version: Int? = nil,
-                inProcess: Bool = false) {
+                inProcess: Bool = false,
+                graphQLFilterJSON: String? = nil) {
         self.id = id
         self.modelId = modelId
         self.modelName = modelName
@@ -33,18 +35,22 @@ public struct MutationEvent: Model {
         self.createdAt = createdAt
         self.version = version
         self.inProcess = inProcess
+        self.graphQLFilterJSON = graphQLFilterJSON
     }
 
     public init<M: Model>(model: M,
                           mutationType: MutationType,
-                          version: Int? = nil) throws {
+                          version: Int? = nil,
+                          graphQLFilterJSON: String? = nil) throws {
         let modelType = type(of: model)
         let json = try model.toJSON()
         self.init(modelId: model.id,
                   modelName: modelType.schema.name,
                   json: json,
                   mutationType: mutationType,
-                  version: version)
+                  version: version,
+                  graphQLFilterJSON: graphQLFilterJSON)
+
     }
 
     public func decodeModel() throws -> Model {

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

@@ -53,6 +53,11 @@ struct GraphQLResponseDecoder {
 
         case (.some(let data), .some(let errors)):
             do {
+                if data.count == 1, let first = data.first, case .null = first.value {
+                    let responseErrors = try decodeErrors(graphQLErrors: errors)
+                    return GraphQLResponse<R>.failure(.error(responseErrors))
+                }
+
                 let jsonValue = JSONValue.object(data)
                 let responseData = try decode(graphQLData: jsonValue,
                                               into: responseType,