fix: unstable_cache should not cache new result in draft mode

packages/next/src/server/web/spec-extension/unstable-cache.ts

@@ -267,15 +267,19 @@ export function unstable_cache<T extends Callback>(
         cb,
         ...args
       )
-      cacheNewResult(
-        result,
-        incrementalCache,
-        cacheKey,
-        tags,
-        options.revalidate,
-        fetchIdx,
-        fetchUrl
-      )
+
+      if (!staticGenerationStore.isDraftMode) {
+        cacheNewResult(
+          result,
+          incrementalCache,
+          cacheKey,
+          tags,
+          options.revalidate,
+          fetchIdx,
+          fetchUrl
+        )
+      }
+
       return result
     } else {
       noStoreFetchIdx += 1

test/e2e/app-dir/app-static/app-static.test.ts

@@ -3489,6 +3489,26 @@ describe('app-dir static/dynamic handling', () => {
       expect(data).not.toEqual(data2)
     })
 
+    it('should not cache new result in draft mode', async () => {
+      const draftRes = await next.fetch('/api/draft-mode?status=enable')
+      const setCookie = draftRes.headers.get('set-cookie')
+      const cookieHeader = { Cookie: setCookie?.split(';', 1)[0] }
+
+      expect(cookieHeader.Cookie).toBeTruthy()
+
+      const res = await next.fetch('/unstable-cache/dynamic', {
+        headers: cookieHeader,
+      })
+      const html = await res.text()
+      const data = cheerio.load(html)('#cached-data').text()
+
+      const res2 = await next.fetch('/unstable-cache/dynamic')
+      const html2 = await res2.text()
+      const data2 = cheerio.load(html2)('#cached-data').text()
+
+      expect(data).not.toEqual(data2)
+    })
+
     it('should not error when retrieving the value undefined', async () => {
       const res = await next.fetch('/unstable-cache/dynamic-undefined')
       const html = await res.text()