fix(query-core): do not schedule garbage collection on the server

.changeset/quiet-timers-rest.md

@@ -0,0 +1,5 @@
+---
+'@tanstack/query-core': patch
+---
+
+Do not schedule garbage collection on the server. A timer scheduled during server rendering captures the async context it was created in and keeps that whole render alive until it fires, while the client it would clean up is dropped with the response. Only queries and mutations with an explicit finite `gcTime` were affected, since the server default is already `Infinity`.

packages/query-core/src/__tests__/query.test.tsx

@@ -12,6 +12,7 @@ import {
   QueryObserver,
   dehydrate,
   hydrate,
+  timeoutManager,
 } from '..'
 import { hashQueryKeyByOptions } from '../utils'
 import { mockOnlineManagerIsOnline, setIsServer } from './utils'
@@ -983,6 +984,25 @@ describe('query', () => {
     }
   })
 
+  it('should not schedule garbage collection on the server, even with an explicit gcTime', () => {
+    const resetIsServer = setIsServer(true)
+    const scheduled = vi.spyOn(timeoutManager, 'setTimeout')
+
+    try {
+      const query = queryCache.build(queryClient, {
+        queryKey: queryKey(),
+        queryFn: () => 'data',
+        gcTime: 1000,
+      })
+
+      expect(query.gcTime).toBe(1000)
+      expect(scheduled).not.toHaveBeenCalled()
+    } finally {
+      scheduled.mockRestore()
+      resetIsServer()
+    }
+  })
+
   it('constructor should call initialDataUpdatedAt if defined as a function', async () => {
     const key = queryKey()
 

packages/query-core/src/removable.ts

@@ -14,6 +14,10 @@ export abstract class Removable {
   protected scheduleGc(): void {
     this.clearGcTimeout()
 
+    if (isServerEnvironment()) {
+      return
+    }
+
     if (isValidTimeout(this.gcTime)) {
       this.#gcTimeout = timeoutManager.setTimeout(() => {
         this.optionalRemove()