return-fetch/dist/index.cjs.map

A very light and simple library to extend fetch by implementing request, response interceptors.

{"version":3,"file":"index.cjs","sources":["../src/index.ts"],"sourcesContent":["/**\n * A simple and powerful high order function to extend fetch.\n *\n * @packageDocumentation\n */\n\n/**\n * Arguments of fetch function.\n *\n * @throws {Error} if a first argument of fetch is `Request` object. only string and URL are supported.\n * @see {fetch, RequestInfo, Request}\n *\n * @public\n */\nexport type FetchArgs = [string | URL, RequestInit | undefined];\n\n/**\n * Type of `returnFetch` function.\n * It is useful for whom want to write customized returnFetch function.\n *\n * @public\n */\nexport type ReturnFetch = typeof returnFetch;\n\n/**\n * Options of `returnFetch` function.\n *\n * @public\n */\nexport type ReturnFetchDefaultOptions = {\n  /**\n   * `fetch` function to be used in `returnFetch` function.\n   * If not provided, `fetch` function in global scope will be used.\n   * Any fetch implementation can be used, such as `node-fetch`, `cross-fetch`, `isomorphic-fetch`, etc.\n   *\n   * a `fetch` function created by `returnFetch` also can be used here.\n   *\n   * @public\n   */\n  fetch?: ReturnType<ReturnFetch>;\n  /**\n   * Base URL of fetch. It will be used when the first argument of fetch is relative URL.\n   *\n   * @public\n   */\n  baseUrl?: string | URL;\n  /**\n   * Default headers of fetch. It will be used when the second argument of fetch does not have `headers` property.\n   * If it is provided and `headers` also provided when calling a `fetch`, headers will be merged.\n   * Priority of headers is `requestInit.headers` > `defaultOptions.headers`. Duplicated headers will be overwritten.\n   *\n   * @public\n   */\n  headers?: HeadersInit;\n  interceptors?: {\n    /**\n     * Request interceptor. It will be called before request.\n     *\n     * @param requestArgs Arguments of fetch function.\n     * @param fetch the `fetch` you provided at {@link ReturnFetchDefaultOptions['fetch']}\n     *\n     * @public\n     */\n    request?: (\n      requestArgs: FetchArgs,\n      fetch: NonNullable<ReturnFetchDefaultOptions[\"fetch\"]>,\n    ) => Promise<FetchArgs>;\n    /**\n     * Response interceptor. It will be called after response.\n     *\n     * @param response Response object received from fetch function.\n     * @param requestArgs Arguments of fetch function.\n     * @param fetch the `fetch` you provided at {@link ReturnFetchDefaultOptions['fetch']}\n     *\n     * @public\n     */\n    response?: (\n      response: Response,\n      requestArgs: FetchArgs,\n      fetch: NonNullable<ReturnFetchDefaultOptions[\"fetch\"]>,\n    ) => Promise<Response>;\n  };\n};\n\nconst applyDefaultOptions = (\n  [input, requestInit]: FetchArgs,\n  defaultOptions?: ReturnFetchDefaultOptions,\n): FetchArgs => {\n  const headers = new Headers(defaultOptions?.headers);\n  new Headers(requestInit?.headers).forEach((value, key) => {\n    headers.set(key, value);\n  });\n\n  let inputToReturn: FetchArgs[0] = input;\n  if (defaultOptions?.baseUrl) {\n    inputToReturn = new URL(input, defaultOptions.baseUrl);\n  }\n\n  return [\n    inputToReturn,\n    {\n      ...requestInit,\n      headers,\n    },\n  ];\n};\n\n// To handle Request object we need to read body as ArrayBuffer.\n// If you have a better way, please let me know.\nconst mergeRequestObjectWithRequestInit = async (\n  request: Request,\n  requestInit?: RequestInit,\n): Promise<RequestInit> => {\n  const mergedRequest = new Request(request, requestInit);\n\n  const body = await mergedRequest.arrayBuffer();\n\n  return {\n    method: mergedRequest.method,\n    headers: mergedRequest.headers,\n    body: body.byteLength ? body : undefined,\n    referrer: mergedRequest.referrer,\n    referrerPolicy: mergedRequest.referrerPolicy,\n    mode: mergedRequest.mode,\n    cache: mergedRequest.cache,\n    redirect: mergedRequest.redirect,\n    credentials: mergedRequest.credentials,\n    integrity: mergedRequest.integrity,\n    keepalive: mergedRequest.keepalive,\n    signal: mergedRequest.signal,\n    window: requestInit?.window,\n  };\n};\n\nconst normalizeArgs = async (\n  ...args: Parameters<typeof fetch>\n): Promise<FetchArgs> => {\n  let input: string | URL;\n  let requestInit: RequestInit | undefined;\n  if (args[0] instanceof Request) {\n    input = args[0].url;\n    requestInit = await mergeRequestObjectWithRequestInit(args[0], args[1]);\n  } else {\n    input = args[0];\n    requestInit = args[1];\n  }\n\n  return [input, requestInit];\n};\n\nconst returnFetch =\n  (defaultOptions?: ReturnFetchDefaultOptions) =>\n  async (...args: Parameters<typeof fetch>): Promise<Response> => {\n    const defaultOptionAppliedArgs = applyDefaultOptions(\n      await normalizeArgs(...args),\n      defaultOptions,\n    );\n\n    // apply request interceptor\n    const fetchProvided = defaultOptions?.fetch || fetch;\n    let requestInterceptorAppliedArgs: FetchArgs;\n    if (defaultOptions?.interceptors?.request) {\n      requestInterceptorAppliedArgs =\n        await defaultOptions?.interceptors?.request?.(\n          defaultOptionAppliedArgs,\n          fetchProvided,\n        );\n    } else {\n      requestInterceptorAppliedArgs = defaultOptionAppliedArgs;\n    }\n\n    // ajax call\n    const response = await fetchProvided(...requestInterceptorAppliedArgs);\n\n    // apply response interceptor\n    return (\n      defaultOptions?.interceptors?.response?.(\n        response,\n        requestInterceptorAppliedArgs,\n        fetchProvided,\n      ) || response\n    );\n  };\n\nexport default returnFetch;\n"],"names":["normalizeArgs","args","input","requestInit","_temp2","slice","call","arguments","_temp","Request","url","Promise","resolve","request","mergedRequest","arrayBuffer","then","body","method","headers","byteLength","undefined","referrer","referrerPolicy","mode","cache","redirect","credentials","integrity","keepalive","signal","window","e","reject","mergeRequestObjectWithRequestInit","_mergeRequestObjectWi","defaultOptions","apply","_normalizeArgs","_temp4","fetchProvided","requestInterceptorAppliedArgs","response","_defaultOptions$inter2","interceptors","defaultOptionAppliedArgs","_ref","Headers","forEach","value","key","set","inputToReturn","baseUrl","URL","_extends","applyDefaultOptions","fetch","_temp3","_defaultOptions$inter3","_defaultOptions$inter4","_defaultOptions$inter"],"mappings":"oOAoFA,IAkDMA,EAAA,WAEkB,IAAA,IADnBC,EAECC,EACAC,EAFkBC,EAAAA,WAWtB,MAAO,CAACF,EAAOC,EAAa,EAZzBF,EAA8B,GAAAI,MAAAC,KAAAC,WAGQ,IAAAC,EACrCP,WAAAA,GAAAA,EAAK,aAAcQ,QACD,OAApBP,EAAQD,EAAK,GAAGS,IAAIC,QAAAC,iBA9BtBC,EACAV,GACwB,IACxB,IAAMW,EAAgB,IAAIL,QAAQI,EAASV,GAAa,OAAAQ,QAAAC,QAErCE,EAAcC,eAAaC,KAAxCC,SAAAA,GAEN,MAAO,CACLC,OAAQJ,EAAcI,OACtBC,QAASL,EAAcK,QACvBF,KAAMA,EAAKG,WAAaH,OAAOI,EAC/BC,SAAUR,EAAcQ,SACxBC,eAAgBT,EAAcS,eAC9BC,KAAMV,EAAcU,KACpBC,MAAOX,EAAcW,MACrBC,SAAUZ,EAAcY,SACxBC,YAAab,EAAca,YAC3BC,UAAWd,EAAcc,UACzBC,UAAWf,EAAce,UACzBC,OAAQhB,EAAcgB,OACtBC,OAAmB,MAAX5B,OAAW,EAAXA,EAAa4B,OACrB,EACJ,CAAC,MAAAC,GAAA,OAAArB,QAAAsB,OAAAD,EAAA,CAAA,CASuBE,CAAkCjC,EAAK,GAAIA,EAAK,KAAGe,KAAAmB,SAAAA,GAAvEhC,EAAWgC,CAA6D,GAExEjC,EAAQD,EAAK,GACbE,EAAcF,EAAK,GALjBA,UAKoBU,QAAAC,QAAAJ,GAAAA,EAAAQ,KAAAR,EAAAQ,KAAAZ,GAAAA,IAI1B,CAAC,MAAA4B,GAAArB,OAAAA,QAAAsB,OAAAD,EAAA,CAAA,iBAGC,SAACI,GAC8D,OAAA,WAAA,IAAAzB,OAAAA,QAAAC,QAErDZ,EAAaqC,gBAAAhC,MAAAC,KAFwCC,aAE/BS,KAAAsB,SAAAA,GAAAC,SAAAA,IAAA5B,OAAAA,QAAAC,QAkBP4B,EAAaH,WAAA,EAAII,IAA8BzB,cAAhE0B,GAAQ,IAAAC,EAGd,OACgB,MAAdP,GAA4B,OAAdO,EAAdP,EAAgBQ,eAAhBD,MAAAA,EAA8BD,cAA9BC,EAAAA,EAA8BD,SAC5BA,EACAD,EACAD,KACGE,CACL,EA5BF,CAAA,IAOID,EAPEI,EArEkB,SAAHC,EAEvBV,GACa,IAFZlC,EAAK4C,EAAA,GAAE3C,EAAW2C,EAAA,GAGb3B,EAAU,IAAI4B,cAAQX,SAAAA,EAAgBjB,SAC5C,IAAI4B,QAAmB,MAAX5C,OAAW,EAAXA,EAAagB,SAAS6B,QAAQ,SAACC,EAAOC,GAChD/B,EAAQgC,IAAID,EAAKD,EACnB,GAEA,IAAIG,EAA8BlD,EAKlC,OAJkB,MAAdkC,GAAAA,EAAgBiB,UAClBD,EAAgB,IAAIE,IAAIpD,EAAOkC,EAAeiB,UAGzC,CACLD,EAAaG,EAAA,CAAA,EAERpD,EAAW,CACdgB,QAAAA,IAGN,CAgDqCqC,CAAmBlB,EAElDF,GAIII,GAAgBJ,MAAAA,OAAAA,EAAAA,EAAgBqB,QAASA,MACFC,WAAAC,GACJC,IAAAA,EADI,GAC3B,MAAdxB,GAAAuB,OAAcA,EAAdvB,EAAgBQ,eAAhBe,EAA8B9C,QAAOF,OAAAA,QAAAC,QAEjB,MAAdwB,GAAAwB,OAAcA,EAAdxB,EAAgBQ,eAAhBgB,MAAAA,EAA8B/C,aAA9B+C,EAAAA,EAA8B/C,QAClCgC,EACAL,IACDxB,KAAA6C,SAAAA,GAJHpB,EAA6BoB,CAIzB,GAEJpB,EAAgCI,CAAyB,IAAA,OAAAa,GAAAA,EAAA1C,KAAA0C,EAAA1C,KAAAuB,GAAAA,GAAA,EAc7D,CAAC,MAAAP,GAAArB,OAAAA,QAAAsB,OAAAD,EAEH,CAAA,CAAA"}