From 38563cfdb8e72030d2316cc31880d5f99741c064 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?N=C3=ADcholas=20Andr=C3=A9?= <nicholasio.oliveira@gmail.com>
Date: Wed, 17 Apr 2024 17:08:41 -0300
Subject: [PATCH] Fix/cache before set (#750)

---
 .changeset/witty-swans-tap.md                 |  6 +++
 .../server/__tests__/fetchHookDataa-cache.ts  | 42 +++++++++++++++++++
 .../next/src/data/server/fetchHookData.ts     |  8 ++--
 3 files changed, 53 insertions(+), 3 deletions(-)
 create mode 100644 .changeset/witty-swans-tap.md

diff --git a/.changeset/witty-swans-tap.md b/.changeset/witty-swans-tap.md
new file mode 100644
index 000000000..8c48a5e33
--- /dev/null
+++ b/.changeset/witty-swans-tap.md
@@ -0,0 +1,6 @@
+---
+"@headstartwp/core": patch
+"@headstartwp/next": patch
+---
+
+Fix cache.beforeSet
diff --git a/packages/next/src/data/server/__tests__/fetchHookDataa-cache.ts b/packages/next/src/data/server/__tests__/fetchHookDataa-cache.ts
index dd890be9a..21c4aaf0e 100644
--- a/packages/next/src/data/server/__tests__/fetchHookDataa-cache.ts
+++ b/packages/next/src/data/server/__tests__/fetchHookDataa-cache.ts
@@ -2,6 +2,7 @@ import { enableFetchMocks } from 'jest-fetch-mock';
 import { HeadlessConfig, setHeadstartWPConfig } from '@headstartwp/core';
 
 import { usePosts } from '../../hooks/usePosts';
+import { usePost } from '../../hooks/usePost';
 
 import { fetchHookData } from '../fetchHookData';
 import cache from '../cache';
@@ -125,4 +126,45 @@ describe('fetchHookData caching', () => {
 		expect(config.cache.beforeSet).toHaveBeenCalledTimes(1);
 		expect(result.data.isCached).toBe(true);
 	});
+
+	it('caches with beforeSet without mutating the fetched data', async () => {
+		const config = {
+			useWordPressPlugin: true,
+			cache: {
+				enabled: true,
+
+				afterGet: async (options, data) => {
+					return data;
+				},
+
+				beforeSet: async (options, data) => {
+					return {
+						...data,
+						result: {
+							...data.result,
+							beforeSetField: true,
+						},
+					};
+				},
+
+				cacheHandler: {
+					set: async (key, data, ttl) => {
+						cache.set(key, data, ttl);
+					},
+					get: async (key) => {
+						return cache.get(key);
+					},
+				},
+			},
+		} satisfies HeadlessConfig;
+
+		setHeadstartWPConfig(config);
+
+		fetchMock.mockResponseOnce(JSON.stringify([{ id: 10 }]));
+
+		const result = await fetchHookData(usePost.fetcher(), {}, { params: { slug: 'test3' } });
+
+		expect(result.data.result.id).toBe(10);
+		expect(result.data.result.beforeSetField).toBeUndefined();
+	});
 });
diff --git a/packages/next/src/data/server/fetchHookData.ts b/packages/next/src/data/server/fetchHookData.ts
index b13ae3d49..262f3f06a 100644
--- a/packages/next/src/data/server/fetchHookData.ts
+++ b/packages/next/src/data/server/fetchHookData.ts
@@ -265,7 +265,7 @@ export async function fetchHookData<T = unknown, P extends EndpointParams = Endp
 			}
 
 			if (typeof cache.beforeSet === 'function') {
-				data = await cache.beforeSet(
+				const beforeSetData = await cache.beforeSet(
 					{
 						fetchStrategy,
 						params,
@@ -275,9 +275,11 @@ export async function fetchHookData<T = unknown, P extends EndpointParams = Endp
 					},
 					data,
 				);
-			}
 
-			await cache.cacheHandler.set(cacheKey, data, cache.ttl);
+				await cache.cacheHandler.set(cacheKey, beforeSetData, cache.ttl);
+			} else {
+				await cache.cacheHandler.set(cacheKey, data, cache.ttl);
+			}
 		}
 	} else {
 		data.isCached = true;