test(query-core): add test case for query (#9145)

* test(query-core): add test case for query

* test(query-core): use hashQueryKeyByOptions

* add test case about "should call initialData function when it is a function"

* reflect feedback

---------

Co-authored-by: Dominik Dorfmeister <office@dorfmeister.cc>

Author: minseong0324

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

@@ -5,14 +5,21 @@ import {
   sleep,
 } from '@tanstack/query-test-utils'
 import {
+  Query,
   QueryClient,
   QueryObserver,
   dehydrate,
   hydrate,
   isCancelledError,
 } from '..'
+import { hashQueryKeyByOptions } from '../utils'
 import { mockOnlineManagerIsOnline, setIsServer } from './utils'
-import type { QueryCache, QueryFunctionContext, QueryObserverResult } from '..'
+import type {
+  QueryCache,
+  QueryFunctionContext,
+  QueryKey,
+  QueryObserverResult,
+} from '..'
 
 describe('query', () => {
   let queryClient: QueryClient
@@ -1019,4 +1026,73 @@ describe('query', () => {
     await vi.advanceTimersByTimeAsync(10)
     expect(query.state.status).toBe('error')
   })
+
+  test('should use persister if provided', async () => {
+    const key = queryKey()
+
+    await queryClient.prefetchQuery({
+      queryKey: key,
+      queryFn: () => 'data',
+      persister: () => Promise.resolve('persisted data'),
+    })
+
+    const query = queryCache.find({ queryKey: key })!
+    expect(query.state.data).toBe('persisted data')
+  })
+
+  test('should use queryFn from observer if not provided in options', async () => {
+    const key = queryKey()
+    const queryFn = () => Promise.resolve('data')
+    const observer = new QueryObserver(queryClient, {
+      queryKey: key,
+      queryFn: queryFn,
+    })
+
+    const query = new Query({
+      client: queryClient,
+      queryKey: key,
+      queryHash: hashQueryKeyByOptions(key),
+    })
+
+    query.addObserver(observer)
+
+    await query.fetch()
+    const result = await query.state.data
+    expect(result).toBe('data')
+    expect(query.options.queryFn).toBe(queryFn)
+  })
+
+  test('should log error when queryKey is not an array', async () => {
+    const consoleMock = vi.spyOn(console, 'error')
+    const key: unknown = 'string-key'
+
+    await queryClient.prefetchQuery({
+      queryKey: key as QueryKey,
+      queryFn: () => 'data',
+    })
+
+    expect(consoleMock).toHaveBeenCalledWith(
+      "As of v4, queryKey needs to be an Array. If you are using a string like 'repoData', please change it to an Array, e.g. ['repoData']",
+    )
+
+    consoleMock.mockRestore()
+  })
+
+  test('should call initialData function when it is a function', () => {
+    const key = queryKey()
+    const initialDataFn = vi.fn(() => 'initial data')
+
+    const query = new Query({
+      client: queryClient,
+      queryKey: key,
+      queryHash: hashQueryKeyByOptions(key),
+      options: {
+        queryFn: () => 'data',
+        initialData: initialDataFn,
+      },
+    })
+
+    expect(initialDataFn).toHaveBeenCalledTimes(1)
+    expect(query.state.data).toBe('initial data')
+  })
 })