how throw a error in switchChain?

[baixiaoyu2997]

 async switchChain({ chainId }) {
        const _chainId = chainId
        const res = await window?.xxx?.request({
          method: 'switchNetwork',
          params: {
            networkType: isxxxMainnet(_chainId) ? 'M' : 'T',
          },
        })

        if (!res?.result) {
          emitter.emit('error', { error: 'user cancel switch network' })
          Promise.reject('user cancel switch network')
          return getChain(appRuntimeConfig.chainId)!
        }
        console.log('=====in switchChain1')
        // NOTE: onChainChanged not support by titan wallet
        this.onChainChanged(String(_chainId))
        return getChain(_chainId, CHAIN_FAMILY.xxx)!
      },

No matter what I do, the status is success

const { data, error, switchChainAsync, status: switchStatus } = useSwitchChain()
  useEffect(() => {
    if (switchStatus === 'success' && data) {
      // window.location.reload()
      console.log('=========switched', data)
    }
  }, [switchStatus, data])

EDIT:
i solved the issue, change to:

if (!res?.result) {
          if (res?.message === 'The current network is already Testnet') {
            this.onChainChanged(String(_chainId))
            return getChain(appRuntimeConfig.chainId)!
          }
          // emitter.emit('error', { error: 'user cancel switch network' })
          return Promise.reject(res?.message)
        }```