fix(datastore): fix stop then start API call pattern (#2529)

* chore(datastore): add forceSync unit & Integ test

* fix(datastore): address PR comments

* remove changes to testConcurrentSave

Co-authored-by: Michael Law <[email protected]>

Author: manaswi223

AmplifyPlugins/DataStore/Sources/AWSDataStorePlugin/AWSDataStorePlugin+DataStoreBaseBehavior.swift

@@ -419,14 +419,17 @@ extension AWSDataStorePlugin: DataStoreBaseBehavior {
                 dispatchedModelSynced.set(false)
             }
             if storageEngine == nil {
-
-                completion(.successfulVoid)
+                queue.async {
+                    completion(.successfulVoid)
+                }
                 return
             }
 
             storageEngine.stopSync { result in
                 self.storageEngine = nil
-                completion(result)
+                self.queue.async {
+                    completion(result)
+                }
             }
         }
     }
@@ -451,12 +454,16 @@ extension AWSDataStorePlugin: DataStoreBaseBehavior {
                 dispatchedModelSynced.set(false)
             }
             if storageEngine == nil {
-                completion(.successfulVoid)
+                queue.async {
+                    completion(.successfulVoid)
+                }
                 return
             }
             storageEngine.clear { result in
                 self.storageEngine = nil
-                completion(result)
+                self.queue.async {
+                    completion(result)
+                }
             }
         }
     }

AmplifyPlugins/DataStore/Sources/AWSDataStorePlugin/AWSDataStorePlugin.swift

@@ -54,6 +54,7 @@ final public class AWSDataStorePlugin: DataStoreCategoryPlugin {
 
     var storageEngine: StorageEngineBehavior!
     var storageEngineInitQueue = DispatchQueue(label: "AWSDataStorePlugin.storageEngineInitQueue")
+    var queue = DispatchQueue(label: "AWSDataStorePlugin.queue", target: DispatchQueue.global())
     var storageEngineBehaviorFactory: StorageEngineBehaviorFactory
 
     var iStorageEngineSink: Any?

AmplifyPlugins/DataStore/Tests/AWSDataStorePluginTests/Core/AWSDataStorePluginTests.swift

@@ -90,6 +90,81 @@ class AWSDataStorePluginTests: XCTestCase {
         }
         await waitForExpectations(timeout: 1.0)
     }
+    
+    func testStorageEngineStartsOnPluginStopStart() throws {
+        let stopExpectation = expectation(description: "Stop plugin should be called")
+        stopExpectation.isInverted = true
+        let startExpectation = expectation(description: "Start Sync should be called")
+        var currCount = 0
+        let storageEngine = MockStorageEngineBehavior()
+        
+        storageEngine.responders[.stopSync] = StopSyncResponder { _ in
+            stopExpectation.fulfill()
+        }
+        
+        storageEngine.responders[.startSync] = StartSyncResponder { _ in
+            currCount = self.expect(startExpectation, currCount, 1)
+        }
+        
+        let storageEngineBehaviorFactory: StorageEngineBehaviorFactory = {_, _, _, _, _, _  throws in
+            return storageEngine
+        }
+        let dataStorePublisher = DataStorePublisher()
+        let plugin = AWSDataStorePlugin(modelRegistration: TestModelRegistration(),
+                                        storageEngineBehaviorFactory: storageEngineBehaviorFactory,
+                                        dataStorePublisher: dataStorePublisher,
+                                        validAPIPluginKey: "MockAPICategoryPlugin",
+                                        validAuthPluginKey: "MockAuthCategoryPlugin")
+        
+        do {
+            try plugin.configure(using: nil)
+            XCTAssertNil(plugin.storageEngine)
+            
+            plugin.stop(completion: { _ in
+                plugin.start(completion: { _ in })
+            })
+        } catch {
+            XCTFail("DataStore configuration should not fail with nil configuration. \(error)")
+        }
+        waitForExpectations(timeout: 1.0)
+    }
+    
+    func testStorageEngineStartsOnPluginClearStart() throws {
+        let clearExpectation = expectation(description: "Clear should be called")
+        let startExpectation = expectation(description: "Start Sync should be called")
+        var currCount = 0
+        
+        let storageEngine = MockStorageEngineBehavior()
+        storageEngine.responders[.clear] = ClearResponder { _ in
+            currCount = self.expect(clearExpectation, currCount, 1)
+        }
+        
+        storageEngine.responders[.startSync] = StartSyncResponder { _ in
+            currCount = self.expect(startExpectation, currCount, 2)
+        }
+        
+        let storageEngineBehaviorFactory: StorageEngineBehaviorFactory = {_, _, _, _, _, _  throws in
+            return storageEngine
+        }
+        let dataStorePublisher = DataStorePublisher()
+        let plugin = AWSDataStorePlugin(modelRegistration: TestModelRegistration(),
+                                        storageEngineBehaviorFactory: storageEngineBehaviorFactory,
+                                        dataStorePublisher: dataStorePublisher,
+                                        validAPIPluginKey: "MockAPICategoryPlugin",
+                                        validAuthPluginKey: "MockAuthCategoryPlugin")
+        
+        do {
+            try plugin.configure(using: nil)
+            XCTAssertNil(plugin.storageEngine)
+            
+            plugin.clear(completion: { _ in
+                plugin.start(completion: { _ in })
+            })
+        } catch {
+            XCTFail("DataStore configuration should not fail with nil configuration. \(error)")
+        }
+        waitForExpectations(timeout: 1.0)
+    }
 
     func testStorageEngineStartStopStart() throws {
         let startExpectation = expectation(description: "Start Sync should be called with start")

AmplifyPlugins/DataStore/Tests/DataStoreHostApp/AWSDataStorePluginIntegrationTests/DataStoreEndToEndTests.swift

@@ -405,6 +405,21 @@ class DataStoreEndToEndTests: SyncEngineIntegrationTestBase {
         try await Amplify.DataStore.start()
         try await validateSavePost()
     }
+    
+    /// Ensure DataStore.stop followed by DataStore.start is successful
+    ///
+    /// - Given:  DataStore has just configured, but not yet started
+    /// - When:
+    ///    - DataStore.stop
+    ///    - Followed by DataStore.start in the completion of the stop
+    /// - Then:
+    ///    - DataStore should be successfully started
+    func testConfigureAmplifyThenStopStart() async throws {
+        await setUp(withModels: TestModelRegistration())
+        try startAmplify()
+        try await Amplify.DataStore.stop()
+        try await Amplify.DataStore.start()
+    }
 
     /// Ensure the DataStore is automatically started when querying for the first time
     ///
@@ -449,6 +464,21 @@ class DataStoreEndToEndTests: SyncEngineIntegrationTestBase {
         try await validateSavePost()
     }
 
+    /// Ensure DataStore.clear followed by DataStore.start is successful
+    ///
+    /// - Given:  DataStore has just configured, but not yet started
+    /// - When:
+    ///    - DataStore.clear
+    ///    - Followed by DataStore.start in the completion of the clear
+    /// - Then:
+    ///    - DataStore should be successfully started
+    func testConfigureAmplifyThenClearStart() async throws {
+        await setUp(withModels: TestModelRegistration())
+        try startAmplify()
+        try await Amplify.DataStore.clear()
+        try await Amplify.DataStore.start()
+    }
+
     /// Perform concurrent saves and observe the data successfuly synced from cloud. Then delete the items afterwards
     /// and ensure they have successfully synced from cloud
     ///
@@ -461,7 +491,7 @@ class DataStoreEndToEndTests: SyncEngineIntegrationTestBase {
     ///    - Ensure the expected mutation event with version 2 (synced from cloud) is received
     ///
     func testConcurrentSave() async throws {
-        await setUp(withModels: TestModelRegistration())
+        await setUp(withModels: TestModelRegistration(), logLevel: .verbose)
         try await startAmplifyAndWaitForSync()
 
         var posts = [Post]()
@@ -474,8 +504,6 @@ class DataStoreEndToEndTests: SyncEngineIntegrationTestBase {
         }
         let postsSyncedToCloud = expectation(description: "All posts saved and synced to cloud")
         postsSyncedToCloud.expectedFulfillmentCount = count
-        
-
         log.debug("Created posts: [\(posts.map { $0.identifier })]")
 
         let postsCopy = posts
@@ -507,7 +535,6 @@ class DataStoreEndToEndTests: SyncEngineIntegrationTestBase {
                 _ = try await Amplify.DataStore.save(capturedPosts[index])
             }
         }
-
         await waitForExpectations(timeout: 100)
 
         let postsDeletedLocally = expectation(description: "All posts deleted locally")
@@ -548,6 +575,7 @@ class DataStoreEndToEndTests: SyncEngineIntegrationTestBase {
                 try await Amplify.DataStore.delete(capturedPosts[index])
             }
         }
+        
         await waitForExpectations(timeout: 100)
     }