Fix offline mutations data loss on restart

.changeset/fix-offline-mutations-changes-field.md

@@ -0,0 +1,5 @@
+---
+'@tanstack/offline-transactions': patch
+---
+
+Fix mutation.changes field being lost during offline transaction serialization. Previously, the changes field was not included in serialized mutations, causing it to be empty ({}) after app restart. This led to sync functions receiving incomplete data when using mutation.changes for partial updates.

packages/offline-transactions/src/outbox/TransactionSerializer.ts

@@ -7,11 +7,9 @@ import type {
 import type { Collection, PendingMutation } from '@tanstack/db'
 
 export class TransactionSerializer {
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
   private collections: Record<string, Collection<any, any, any, any, any>>
   private collectionIdToKey: Map<string, string>
 
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
   constructor(
     collections: Record<string, Collection<any, any, any, any, any>>,
   ) {
@@ -32,7 +30,7 @@ export class TransactionSerializer {
       ),
     }
     // Convert the whole object to JSON, handling dates
-    return JSON.stringify(serialized, (key, value) => {
+    return JSON.stringify(serialized, (_key, value) => {
       if (value instanceof Date) {
         return value.toISOString()
       }
@@ -43,7 +41,7 @@ export class TransactionSerializer {
   deserialize(data: string): OfflineTransaction {
     const parsed: SerializedOfflineTransaction = JSON.parse(
       data,
-      (key, value) => {
+      (_key, value) => {
         // Parse ISO date strings back to Date objects
         if (
           typeof value === `string` &&
@@ -76,6 +74,7 @@ export class TransactionSerializer {
       type: mutation.type,
       modified: this.serializeValue(mutation.modified),
       original: this.serializeValue(mutation.original),
+      changes: this.serializeValue(mutation.changes),
       collectionId: registryKey, // Store registry key instead of collection.id
     }
   }
@@ -93,11 +92,12 @@ export class TransactionSerializer {
       type: data.type as any,
       modified: this.deserializeValue(data.modified),
       original: this.deserializeValue(data.original),
+      changes:
+        data.changes !== undefined ? this.deserializeValue(data.changes) : {},
       collection,
       // These fields would need to be reconstructed by the executor
       mutationId: ``, // Will be regenerated
       key: null, // Will be extracted from the data
-      changes: {}, // Will be recalculated
       metadata: undefined,
       syncMetadata: {},
       optimistic: true,
@@ -118,7 +118,7 @@ export class TransactionSerializer {
     if (typeof value === `object`) {
       const result: any = Array.isArray(value) ? [] : {}
       for (const key in value) {
-        if (value.hasOwnProperty(key)) {
+        if (Object.prototype.hasOwnProperty.call(value, key)) {
           result[key] = this.serializeValue(value[key])
         }
       }
@@ -140,7 +140,7 @@ export class TransactionSerializer {
     if (typeof value === `object`) {
       const result: any = Array.isArray(value) ? [] : {}
       for (const key in value) {
-        if (value.hasOwnProperty(key)) {
+        if (Object.prototype.hasOwnProperty.call(value, key)) {
           result[key] = this.deserializeValue(value[key])
         }
       }

packages/offline-transactions/src/types.ts

@@ -21,6 +21,7 @@ export interface SerializedMutation {
   type: string
   modified: any
   original: any
+  changes: any
   collectionId: string
 }
 
@@ -88,7 +89,6 @@ export interface StorageDiagnostic {
 }
 
 export interface OfflineConfig {
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
   collections: Record<string, Collection<any, any, any, any, any>>
   mutationFns: Record<string, OfflineMutationFn>
   storage?: StorageAdapter