From 26ce5dfb0270009fc10f003f5627046ddaf5ae4e Mon Sep 17 00:00:00 2001
From: Alex Hinson <alexmhinson@gmail.com>
Date: Fri, 18 Sep 2020 13:58:57 -0700
Subject: [PATCH] fix(@aws-amplify/datastore): use runExclusive when enqueuing
 (#6828)

---
 packages/datastore/src/sync/outbox.ts         | 86 ++++++++++---------
 .../datastore/src/sync/processors/mutation.ts |  2 +-
 2 files changed, 45 insertions(+), 43 deletions(-)

diff --git a/packages/datastore/src/sync/outbox.ts b/packages/datastore/src/sync/outbox.ts
index d51fdc01593..10dad1b53be 100644
--- a/packages/datastore/src/sync/outbox.ts
+++ b/packages/datastore/src/sync/outbox.ts
@@ -27,54 +27,56 @@ class MutationEventOutbox {
 		storage: Storage,
 		mutationEvent: MutationEvent
 	): Promise<void> {
-		const mutationEventModelDefinition = this.schema.namespaces[SYNC].models[
-			'MutationEvent'
-		];
-
-		const predicate = ModelPredicateCreator.createFromExisting<MutationEvent>(
-			mutationEventModelDefinition,
-			c =>
-				c
-					.modelId('eq', mutationEvent.modelId)
-					.id('ne', this.inProgressMutationEventId)
-		);
+		storage.runExclusive(async s => {
+			const mutationEventModelDefinition = this.schema.namespaces[SYNC].models[
+				'MutationEvent'
+			];
 
-		const [first] = await storage.query(this.MutationEvent, predicate);
+			const predicate = ModelPredicateCreator.createFromExisting<MutationEvent>(
+				mutationEventModelDefinition,
+				c =>
+					c
+						.modelId('eq', mutationEvent.modelId)
+						.id('ne', this.inProgressMutationEventId)
+			);
 
-		if (first === undefined) {
-			await storage.save(mutationEvent, undefined, this.ownSymbol);
-			return;
-		}
+			const [first] = await s.query(this.MutationEvent, predicate);
 
-		const { operation: incomingMutationType } = mutationEvent;
+			if (first === undefined) {
+				await s.save(mutationEvent, undefined, this.ownSymbol);
+				return;
+			}
 
-		if (first.operation === TransformerMutationType.CREATE) {
-			if (incomingMutationType === TransformerMutationType.DELETE) {
-				// delete all for model
-				await storage.delete(this.MutationEvent, predicate);
+			const { operation: incomingMutationType } = mutationEvent;
+
+			if (first.operation === TransformerMutationType.CREATE) {
+				if (incomingMutationType === TransformerMutationType.DELETE) {
+					// delete all for model
+					await s.delete(this.MutationEvent, predicate);
+				} else {
+					// first gets updated with incoming's data, condition intentionally skiped
+					await s.save(
+						this.MutationEvent.copyOf(first, draft => {
+							draft.data = mutationEvent.data;
+						}),
+						undefined,
+						this.ownSymbol
+					);
+				}
 			} else {
-				// first gets updated with incoming's data, condition intentionally skiped
-				await storage.save(
-					this.MutationEvent.copyOf(first, draft => {
-						draft.data = mutationEvent.data;
-					}),
-					undefined,
-					this.ownSymbol
-				);
-			}
-		} else {
-			const { condition: incomingConditionJSON } = mutationEvent;
-			const incomingCondition = JSON.parse(incomingConditionJSON);
-
-			// If no condition
-			if (Object.keys(incomingCondition).length === 0) {
-				// delete all for model
-				await storage.delete(this.MutationEvent, predicate);
-			}
+				const { condition: incomingConditionJSON } = mutationEvent;
+				const incomingCondition = JSON.parse(incomingConditionJSON);
+
+				// If no condition
+				if (Object.keys(incomingCondition).length === 0) {
+					// delete all for model
+					await s.delete(this.MutationEvent, predicate);
+				}
 
-			// Enqueue new one
-			await storage.save(mutationEvent, undefined, this.ownSymbol);
-		}
+				// Enqueue new one
+				await s.save(mutationEvent, undefined, this.ownSymbol);
+			}
+		});
 	}
 
 	public async dequeue(storage: StorageFacade): Promise<MutationEvent> {
diff --git a/packages/datastore/src/sync/processors/mutation.ts b/packages/datastore/src/sync/processors/mutation.ts
index 0d329d89f8f..842eabff92c 100644
--- a/packages/datastore/src/sync/processors/mutation.ts
+++ b/packages/datastore/src/sync/processors/mutation.ts
@@ -310,7 +310,7 @@ class MutationProcessor {
 											: null,
 									});
 								} catch (err) {
-									logger.warn("failed to execute errorHandler", err);
+									logger.warn('failed to execute errorHandler', err);
 								} finally {
 									// Return empty tuple, dequeues the mutation
 									return error.data