From 6aebe3bf1affb52518bf1223abddd571436b2068 Mon Sep 17 00:00:00 2001
From: Francesco Giordano <francescogior@gmail.com>
Date: Thu, 15 Jun 2023 16:35:42 +0200
Subject: [PATCH] Pass displayed data as second parameter of functional
 optimistic data

---
 _internal/src/types.ts        | 4 +++-
 _internal/src/utils/mutate.ts | 2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/_internal/src/types.ts b/_internal/src/types.ts
index 3b399b392..5db1b6679 100644
--- a/_internal/src/types.ts
+++ b/_internal/src/types.ts
@@ -317,7 +317,9 @@ export type MutatorOptions<Data = any> = {
   populateCache?:
     | boolean
     | ((result: any, currentData: Data | undefined) => Data)
-  optimisticData?: Data | ((currentData?: Data) => Data)
+  optimisticData?:
+    | Data
+    | ((currentData: Data | undefined, displayedData: Data | undefined) => Data)
   rollbackOnError?: boolean | ((error: unknown) => boolean)
   throwOnError?: boolean
 }
diff --git a/_internal/src/utils/mutate.ts b/_internal/src/utils/mutate.ts
index 36331933d..2e86ff298 100644
--- a/_internal/src/utils/mutate.ts
+++ b/_internal/src/utils/mutate.ts
@@ -139,7 +139,7 @@ export async function internalMutate<Data>(
     // Do optimistic data update.
     if (hasOptimisticData) {
       optimisticData = isFunction(optimisticData)
-        ? optimisticData(committedData)
+        ? optimisticData(committedData, displayedData)
         : optimisticData
 
       // When we set optimistic data, backup the current committedData data in `_c`.