test(vue-query/useIsFetching): add test for outside scope warning in development mode (#10237)

* test(vue-query/useIsFetching): add test for outside scope warning in development mode

* refactor(vue-query/useIsFetching): wrap outside scope warning test with 'try/finally' for cleanup safety

Author: sukvvon

packages/vue-query/src/__tests__/useIsFetching.test.ts

@@ -98,4 +98,20 @@ describe('useIsFetching', () => {
 
     expect(isFetching.value).toStrictEqual(1)
   })
+
+  test('should warn when used outside of setup function in development mode', () => {
+    vi.stubEnv('NODE_ENV', 'development')
+    const warnSpy = vi.spyOn(console, 'warn').mockImplementation(() => {})
+
+    try {
+      useIsFetching()
+
+      expect(warnSpy).toHaveBeenCalledWith(
+        'vue-query composable like "useQuery()" should only be used inside a "setup()" function or a running effect scope. They might otherwise lead to memory leaks.',
+      )
+    } finally {
+      warnSpy.mockRestore()
+      vi.unstubAllEnvs()
+    }
+  })
 })