function getDocument(src = {}) {
  if (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) {
    if (typeof src === "string" || src instanceof URL) {
      src = { url: src };
    } else if (src instanceof ArrayBuffer || ArrayBuffer.isView(src)) {
      src = { data: src };
    }
  }
  const task = new PDFDocumentLoadingTask();
  const { docId } = task;

  const url = src.url ? getUrlProp(src.url) : null;
  const data = src.data ? getDataProp(src.data) : null;
  const httpHeaders = src.httpHeaders || null;
  const withCredentials = src.withCredentials === true;
  const password = src.password ?? null;
  const rangeTransport =
    src.range instanceof PDFDataRangeTransport ? src.range : null;
  const rangeChunkSize =
    Number.isInteger(src.rangeChunkSize) && src.rangeChunkSize > 0
      ? src.rangeChunkSize
      : 2 ** 16;
  let worker = src.worker instanceof PDFWorker ? src.worker : null;
  const verbosity = src.verbosity;
  // Ignore "data:"-URLs, since they can't be used to recover valid absolute
  // URLs anyway. We want to avoid sending them to the worker-thread, since
  // they contain the *entire* PDF document and can thus be arbitrarily long.
  const docBaseUrl =
    typeof src.docBaseUrl === "string" && !isDataScheme(src.docBaseUrl)
      ? src.docBaseUrl
      : null;
  const cMapUrl = getFactoryUrlProp(src.cMapUrl);
  const cMapPacked = src.cMapPacked !== false;
  const CMapReaderFactory =
    src.CMapReaderFactory ||
    (typeof PDFJSDev !== "undefined" && PDFJSDev.test("GENERIC") && isNodeJS
      ? NodeCMapReaderFactory
      : DOMCMapReaderFactory);
  const iccUrl = getFactoryUrlProp(src.iccUrl);
  const standardFontDataUrl = getFactoryUrlProp(src.standardFontDataUrl);
  const StandardFontDataFactory =
    src.StandardFontDataFactory ||
    (typeof PDFJSDev !== "undefined" && PDFJSDev.test("GENERIC") && isNodeJS
      ? NodeStandardFontDataFactory
      : DOMStandardFontDataFactory);
  const wasmUrl = getFactoryUrlProp(src.wasmUrl);
  const WasmFactory =
    src.WasmFactory ||
    (typeof PDFJSDev !== "undefined" && PDFJSDev.test("GENERIC") && isNodeJS
      ? NodeWasmFactory
      : DOMWasmFactory);
  const ignoreErrors = src.stopAtErrors !== true;
  const maxImageSize =
    Number.isInteger(src.maxImageSize) && src.maxImageSize > -1
      ? src.maxImageSize
      : -1;
  const isEvalSupported = src.isEvalSupported !== false;
  const isOffscreenCanvasSupported =
    typeof src.isOffscreenCanvasSupported === "boolean"
      ? src.isOffscreenCanvasSupported
      : !isNodeJS;
  const isImageDecoderSupported =
    // eslint-disable-next-line no-nested-ternary
    typeof src.isImageDecoderSupported === "boolean"
      ? src.isImageDecoderSupported
      : // eslint-disable-next-line no-nested-ternary
        typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")
        ? true
        : typeof PDFJSDev !== "undefined" && PDFJSDev.test("CHROME")
          ? false
          : !isNodeJS && (FeatureTest.platform.isFirefox || !globalThis.chrome);
  const canvasMaxAreaInBytes = Number.isInteger(src.canvasMaxAreaInBytes)
    ? src.canvasMaxAreaInBytes
    : -1;
  const disableFontFace =
    typeof src.disableFontFace === "boolean" ? src.disableFontFace : isNodeJS;
  const fontExtraProperties = src.fontExtraProperties === true;
  const enableXfa = src.enableXfa === true;
  const ownerDocument = src.ownerDocument || globalThis.document;
  const disableRange = src.disableRange === true;
  const disableStream = src.disableStream === true;
  const disableAutoFetch = src.disableAutoFetch === true;
  const pdfBug = src.pdfBug === true;
  const CanvasFactory =
    src.CanvasFactory ||
    (typeof PDFJSDev !== "undefined" && PDFJSDev.test("GENERIC") && isNodeJS
      ? NodeCanvasFactory
      : DOMCanvasFactory);
  const FilterFactory =
    src.FilterFactory ||
    (typeof PDFJSDev !== "undefined" && PDFJSDev.test("GENERIC") && isNodeJS
      ? NodeFilterFactory
      : DOMFilterFactory);
  const enableHWA = src.enableHWA === true;
  const useWasm = src.useWasm !== false;

  // Parameters whose default values depend on other parameters.
  const length = rangeTransport ? rangeTransport.length : (src.length ?? NaN);
  const useSystemFonts =
    typeof src.useSystemFonts === "boolean"
      ? src.useSystemFonts
      : !isNodeJS && !disableFontFace;
  const useWorkerFetch =
    typeof src.useWorkerFetch === "boolean"
      ? src.useWorkerFetch
      : (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) ||
        !!(
          CMapReaderFactory === DOMCMapReaderFactory &&
          StandardFontDataFactory === DOMStandardFontDataFactory &&
          WasmFactory === DOMWasmFactory &&
          cMapUrl &&
          standardFontDataUrl &&
          wasmUrl &&
          isValidFetchUrl(cMapUrl, document.baseURI) &&
          isValidFetchUrl(standardFontDataUrl, document.baseURI) &&
          isValidFetchUrl(wasmUrl, document.baseURI)
        );

  // Parameters only intended for development/testing purposes.
  const styleElement =
    typeof PDFJSDev === "undefined" || PDFJSDev.test("TESTING")
      ? src.styleElement
      : null;

  // Set the main-thread verbosity level.
  setVerbosityLevel(verbosity);

  // Ensure that the various factories can be initialized, when necessary,
  // since the user may provide *custom* ones.
  const transportFactory = {
    canvasFactory: new CanvasFactory({ ownerDocument, enableHWA }),
    filterFactory: new FilterFactory({ docId, ownerDocument }),
    cMapReaderFactory:
      (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) ||
      useWorkerFetch
        ? null
        : new CMapReaderFactory({ baseUrl: cMapUrl, isCompressed: cMapPacked }),
    standardFontDataFactory:
      (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) ||
      useWorkerFetch
        ? null
        : new StandardFontDataFactory({ baseUrl: standardFontDataUrl }),
    wasmFactory:
      (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) ||
      useWorkerFetch
        ? null
        : new WasmFactory({ baseUrl: wasmUrl }),
  };

  if (!worker) {
    // Worker was not provided -- creating and owning our own. If message port
    // is specified in global worker options, using it.
    worker = PDFWorker.create({
      verbosity,
      port: GlobalWorkerOptions.workerPort,
    });
    task._worker = worker;
  }

  const docParams = {
    docId,
    apiVersion:
      typeof PDFJSDev !== "undefined" && !PDFJSDev.test("TESTING")
        ? PDFJSDev.eval("BUNDLE_VERSION")
        : null,
    data,
    password,
    disableAutoFetch,
    rangeChunkSize,
    length,
    docBaseUrl,
    enableXfa,
    evaluatorOptions: {
      maxImageSize,
      disableFontFace,
      ignoreErrors,
      isEvalSupported,
      isOffscreenCanvasSupported,
      isImageDecoderSupported,
      canvasMaxAreaInBytes,
      fontExtraProperties,
      useSystemFonts,
      useWasm,
      useWorkerFetch,
      cMapUrl,
      iccUrl,
      standardFontDataUrl,
      wasmUrl,
    },
  };
  const transportParams = {
    ownerDocument,
    pdfBug,
    styleElement,
    loadingParams: {
      disableAutoFetch,
      enableXfa,
    },
  };

  worker.promise
    .then(function () {
      if (task.destroyed) {
        throw new Error("Loading aborted");
      }
      if (worker.destroyed) {
        throw new Error("Worker was destroyed");
      }

      const workerIdPromise = worker.messageHandler.sendWithPromise(
        "GetDocRequest",
        docParams,
        data ? [data.buffer] : null
      );

      let networkStream;
      if (rangeTransport) {
        networkStream = new PDFDataTransportStream(rangeTransport, {
          disableRange,
          disableStream,
        });
      } else if (!data) {
        if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) {
          throw new Error("Not implemented: NetworkStream");
        }
        if (!url) {
          throw new Error("getDocument - no `url` parameter provided.");
        }
        // eslint-disable-next-line no-nested-ternary
        const NetworkStream = isValidFetchUrl(url)
          ? PDFFetchStream
          : typeof PDFJSDev !== "undefined" &&
              PDFJSDev.test("GENERIC") &&
              isNodeJS
            ? PDFNodeStream
            : PDFNetworkStream;

        networkStream = new NetworkStream({
          url,
          length,
          httpHeaders,
          withCredentials,
          rangeChunkSize,
          disableRange,
          disableStream,
        });
      }

      return workerIdPromise.then(workerId => {
        if (task.destroyed) {
          throw new Error("Loading aborted");
        }
        if (worker.destroyed) {
          throw new Error("Worker was destroyed");
        }

        const messageHandler = new MessageHandler(docId, workerId, worker.port);
        const transport = new WorkerTransport(
          messageHandler,
          task,
          networkStream,
          transportParams,
          transportFactory
        );
        task._transport = transport;
        messageHandler.send("Ready", null);
      });
    })
    .catch(task._capability.reject);

  return task;
}
This is the main entry point for loading a PDF and interacting with it.

NOTE: If a URL is used to fetch the PDF data a standard Fetch API call (or
XHR as fallback) is used, which means it must follow same origin rules,
e.g. no cross-domain requests without CORS.

@param {string | URL | TypedArray | ArrayBuffer | DocumentInitParameters}
  src - Can be a URL where a PDF file is located, a typed array (Uint8Array)
        already populated with data, or a parameter object.
@returns {PDFDocumentLoadingTask}