Function useFetch

packages/nuxt/src/app/composables/fetch.ts:176–278

(
      request: Ref<ReqT> | ReqT | (() => ReqT),
      arg1?: string | UseFetchOptions<_ResT, DataT, PickKeys, DefaultT, ReqT, Method>,
      arg2?: string,
    )

      opts?: UseFetchOptions<_ResT, DataT, PickKeys, DefaultT, ReqT, Method>,
    ): AsyncData<PickFrom<DataT, [Array<never>] extends [FPickKeys] ? PickKeys : FPickKeys & KeysOf<DataT>> | DefaultT, ErrorT | undefined>
    function useFetch<
      ResT = void,
      ErrorT = FetchError,
      ReqT extends NitroFetchRequest = NitroFetchRequest,
      Method extends AvailableRouterMethod<ReqT> = ResT extends void ? 'get' extends AvailableRouterMethod<ReqT> ? 'get' : AvailableRouterMethod<ReqT> : AvailableRouterMethod<ReqT>,
      _ResT = ResT extends void ? FetchResult<ReqT, Method> : ResT,
      DataT = _ResT,
      PickKeys extends KeysOf<DataT> = KeysOf<DataT>,
      DefaultT = undefined,
    > (
      request: Ref<ReqT> | ReqT | (() => ReqT),
      arg1?: string | UseFetchOptions<_ResT, DataT, PickKeys, DefaultT, ReqT, Method>,
      arg2?: string,
    ) {
      const [opts = {}, autoKey] = typeof arg1 === 'string' ? [{}, arg1] : [arg1, arg2]

      const factoryOptions = (typeof options === 'function' ? options(opts as any) : options) as typeof opts

      // Merge factory options with user options:
      // - defaults mode (plain object): factory < user opts (factory provides defaults)
      // - override mode (function): user opts < factory (factory overrides user opts)
      const {
        server,
        lazy,
        default: defaultFn,
        transform,
        pick,
        watch: watchSources,
        immediate,
        getCachedData,
        deep,
        dedupe,
        timeout,
        ...fetchOptions
      } = {
        ...(typeof options === 'function' ? {} : factoryOptions),
        ...opts,
        ...(typeof options === 'function' ? factoryOptions : {}),
      }

      const _request = computed(() => toValue(request))

      const key = computed(() => toValue(fetchOptions.key) || ('$f' + hash([autoKey, typeof _request.value === 'string' ? _request.value : '', ...generateOptionSegments(fetchOptions)])))

      if (!fetchOptions.baseURL && typeof _request.value === 'string' && (_request.value[0] === '/' && _request.value[1] === '/')) {
        throw new Error('[nuxt] [useFetch] the request URL must not start with "//".')
      }

      const _fetchOptions = reactive<typeof fetchOptions>({
        ...fetchDefaults,
        ...fetchOptions,
        cache: typeof fetchOptions.cache === 'boolean' ? undefined : fetchOptions.cache,
      })

      const _asyncDataOptions: AsyncDataOptions<_ResT, DataT, PickKeys, DefaultT> = {
        server,
        lazy,
        default: defaultFn,