@tanstack/query-core
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The framework agnostic core that powers TanStack Query
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{"version":3,"file":"streamedQuery.cjs","names":["addToEnd","addConsumeAwareSignal"],"sources":["../../src/streamedQuery.ts"],"sourcesContent":["import { addConsumeAwareSignal, addToEnd } from './utils'\nimport type {\n OmitKeyof,\n QueryFunction,\n QueryFunctionContext,\n QueryKey,\n} from './types'\n\ntype BaseStreamedQueryParams<TQueryFnData, TQueryKey extends QueryKey> = {\n /** The function that returns an `AsyncIterable` to stream data from. */\n streamFn: (\n context: QueryFunctionContext<TQueryKey>,\n ) => AsyncIterable<TQueryFnData> | Promise<AsyncIterable<TQueryFnData>>\n /**\n * Defines how refetches are handled.\n * - `'reset'` (default): erases all data and puts the query back into `pending` state.\n * - `'append'`: appends new data to the existing data.\n * - `'replace'`: writes all data to the cache once the stream ends.\n */\n refetchMode?: 'append' | 'reset' | 'replace'\n}\n\ntype SimpleStreamedQueryParams<\n TQueryFnData,\n TQueryKey extends QueryKey,\n> = BaseStreamedQueryParams<TQueryFnData, TQueryKey> & {\n reducer?: never\n initialValue?: never\n}\n\ntype ReducibleStreamedQueryParams<\n TQueryFnData,\n TData,\n TQueryKey extends QueryKey,\n> = BaseStreamedQueryParams<TQueryFnData, TQueryKey> & {\n /**\n * Reduces streamed chunks into the final data shape. Required whenever `TData` is not an\n * array, since there is no default way to accumulate non-array chunks.\n */\n reducer: (acc: TData, chunk: TQueryFnData) => TData\n /**\n * The value used while the first chunk is being fetched, and returned if the stream yields no\n * values. Required together with a custom `reducer`.\n */\n initialValue: TData\n}\n\ntype StreamedQueryParams<TQueryFnData, TData, TQueryKey extends QueryKey> =\n | SimpleStreamedQueryParams<TQueryFnData, TQueryKey>\n | ReducibleStreamedQueryParams<TQueryFnData, TData, TQueryKey>\n\n/**\n * This is a helper function to create a query function that streams data from an AsyncIterable.\n * Data will be an Array of all the chunks received.\n * The query will be in a 'pending' state until the first chunk of data is received, but will go to 'success' after that.\n * The query will stay in fetchStatus 'fetching' until the stream ends.\n * @param options - The `streamFn` that returns an AsyncIterable to stream data from, and the optional\n * `refetchMode`, `reducer`, and `initialValue` options.\n * @returns A query function to pass as `queryFn`.\n * @example\n * ```ts\n * await queryClient.query({\n * queryKey: ['data'],\n * queryFn: streamedQuery({\n * streamFn: fetchDataInChunks,\n * }),\n * })\n * ```\n */\nexport function streamedQuery<\n TQueryFnData = unknown,\n TData = Array<TQueryFnData>,\n TQueryKey extends QueryKey = QueryKey,\n>({\n streamFn,\n refetchMode = 'reset',\n reducer = (items, chunk) =>\n addToEnd(items as Array<TQueryFnData>, chunk) as TData,\n initialValue = [] as TData,\n}: StreamedQueryParams<TQueryFnData, TData, TQueryKey>): QueryFunction<\n TData,\n TQueryKey\n> {\n return async (context) => {\n const query = context.client\n .getQueryCache()\n .find({ queryKey: context.queryKey, exact: true })\n const isRefetch = !!query && query.isFetched()\n if (isRefetch && refetchMode === 'reset') {\n query.setState({\n ...query.resetState,\n fetchStatus: 'fetching',\n })\n }\n\n let result = initialValue\n\n let cancelled = false as boolean\n const streamFnContext = addConsumeAwareSignal<\n OmitKeyof<typeof context, 'signal'>\n >(\n {\n client: context.client,\n meta: context.meta,\n queryKey: context.queryKey,\n pageParam: context.pageParam,\n direction: context.direction,\n },\n () => context.signal,\n () => (cancelled = true),\n )\n\n const stream = await streamFn(streamFnContext)\n\n const isReplaceRefetch = isRefetch && refetchMode === 'replace'\n\n for await (const chunk of stream) {\n if (cancelled) {\n break\n }\n\n if (isReplaceRefetch) {\n // don't append to the cache directly when replace-refetching\n result = reducer(result, chunk)\n } else {\n context.client.setQueryData<TData>(context.queryKey, (prev) =>\n reducer(prev === undefined ? initialValue : prev, chunk),\n )\n }\n }\n\n // finalize result: replace-refetching needs to write to the cache\n if (isReplaceRefetch && !cancelled) {\n context.client.setQueryData<TData>(context.queryKey, result)\n }\n\n const data = context.client.getQueryData<TData>(context.queryKey)\n return data === undefined ? initialValue : data\n }\n}\n"],"mappings":";;;;;;;;;;;;;;;;;;;;;AAqEA,SAAgB,cAId,EACA,UACA,cAAc,SACd,WAAW,OAAO,UAChBA,cAAAA,SAAS,OAA8B,KAAK,GAC9C,eAAe,CAAC,KAIhB;CACA,OAAO,OAAO,YAAY;EACxB,MAAM,QAAQ,QAAQ,OACnB,cAAc,CAAC,CACf,KAAK;GAAE,UAAU,QAAQ;GAAU,OAAO;EAAK,CAAC;EACnD,MAAM,YAAY,CAAC,CAAC,SAAS,MAAM,UAAU;EAC7C,IAAI,aAAa,gBAAgB,SAC/B,MAAM,SAAS;GACb,GAAG,MAAM;GACT,aAAa;EACf,CAAC;EAGH,IAAI,SAAS;EAEb,IAAI,YAAY;EAehB,MAAM,SAAS,MAAM,SAdGC,cAAAA,sBAGtB;GACE,QAAQ,QAAQ;GAChB,MAAM,QAAQ;GACd,UAAU,QAAQ;GAClB,WAAW,QAAQ;GACnB,WAAW,QAAQ;EACrB,SACM,QAAQ,cACP,YAAY,IAGuB,CAAC;EAE7C,MAAM,mBAAmB,aAAa,gBAAgB;EAEtD,WAAW,MAAM,SAAS,QAAQ;GAChC,IAAI,WACF;GAGF,IAAI,kBAEF,SAAS,QAAQ,QAAQ,KAAK;QAE9B,QAAQ,OAAO,aAAoB,QAAQ,WAAW,SACpD,QAAQ,SAAS,KAAA,IAAY,eAAe,MAAM,KAAK,CACzD;EAEJ;EAGA,IAAI,oBAAoB,CAAC,WACvB,QAAQ,OAAO,aAAoB,QAAQ,UAAU,MAAM;EAG7D,MAAM,OAAO,QAAQ,OAAO,aAAoB,QAAQ,QAAQ;EAChE,OAAO,SAAS,KAAA,IAAY,eAAe;CAC7C;AACF"}