fix: allow empty query key (with config enabled)

src/core/config.js

@@ -39,27 +39,23 @@ export const defaultConfigRef = {
 
 export function defaultQueryKeySerializerFn(queryKey) {
   if (!queryKey) {
-    invalidQueryKey()
+    return []
   }
 
   if (!Array.isArray(queryKey)) {
     queryKey = [queryKey]
   }
 
   if (queryKey.some(d => typeof d === 'function')) {
-    invalidQueryKey()
+    throw new Error('A valid query key is required!')
   }
 
   const queryHash = stableStringify(queryKey)
   queryKey = JSON.parse(queryHash)
 
   if (!queryHash) {
-    invalidQueryKey()
+    return []
   }
 
   return [queryHash, queryKey]
 }
-
-function invalidQueryKey() {
-  throw new Error('A valid query key is required!')
-}

src/react/tests/useQuery.test.js

@@ -599,14 +599,14 @@ describe('useQuery', () => {
     rendered.getByText('status: idle')
   })
 
-  it('it should throw when using query syntax and missing required keys', async () => {
+  it('it should throw when using a bad query syntax', async () => {
     // mock console.error to avoid the wall of red text,
     // you could also do this on beforeEach/afterEach
     jest.spyOn(console, 'error')
     console.error.mockImplementation(() => {})
 
     function Page() {
-      useQuery({})
+      useQuery(() => {})
       return null
     }
     expect(() => render(<Page />)).toThrowError(/query key/)