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@aws-amplify/core

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import { Middleware, TransferHandler, Request as RequestBase, Response as ResponseBase } from '../types'; /** * Compose a transfer handler with a core transfer handler and a list of middleware. * @param coreHandler Core transfer handler * @param middleware List of middleware * @returns A transfer handler whose option type is the union of the core * transfer handler's option type and the middleware's option type. * @internal */ export declare const composeTransferHandler: <MiddlewareOptionsArr extends any[] = [], Request_1 extends RequestBase = RequestBase, Response_1 extends ResponseBase = ResponseBase, CoreHandler extends TransferHandler<Request_1, Response_1, any> = TransferHandler<Request_1, Response_1, {}>>(coreHandler: CoreHandler, middleware: OptionToMiddleware<Request_1, Response_1, MiddlewareOptionsArr>) => (request: Request_1, options: MergeNoConflictKeys<[...MiddlewareOptionsArr, InferOptionTypeFromTransferHandler<CoreHandler>]>) => Promise<Response_1>; /** * Type to convert a middleware option type to a middleware type with the given * option type. */ type OptionToMiddleware<Request extends RequestBase, Response extends ResponseBase, Options extends any[]> = Options extends [] ? [] : Options extends [infer LastOption] ? [Middleware<Request, Response, LastOption>] : Options extends [infer FirstOption, ...infer RestOptions] ? [ Middleware<Request, Response, FirstOption>, ...OptionToMiddleware<Request, Response, RestOptions> ] : never; /** * Type to intersect multiple types if they have no conflict keys. */ type MergeNoConflictKeys<Options extends any[]> = Options extends [ infer OnlyOption ] ? OnlyOption : Options extends [infer FirstOption, infer SecondOption] ? FirstOption & SecondOption : Options extends [infer FirstOption, ...infer RestOptions] ? FirstOption & MergeNoConflictKeys<RestOptions> : never; /** * Type to infer the option type of a transfer handler type. */ type InferOptionTypeFromTransferHandler<T extends TransferHandler<any, any, any>> = Parameters<T>[1]; export {};