How to use the pdfjs-dist.disableWorker function in pdfjs-dist

if (typeof options.max !== 'number') {
        options.max = DEFAULT_OPTIONS.max;
    }
    if (typeof options.version !== 'string') {
        options.version = DEFAULT_OPTIONS.version;
    }
    if (options.version === 'default') {
        options.version = DEFAULT_OPTIONS.version;
    }

    ret.version = PDFJS.version;

    // Disable workers to avoid yet another cross-origin issue (workers need
    // the URL of the script to be loaded, and dynamically loading a cross-origin
    // script does not work).
    PDFJS.disableWorker = true;
    let doc;

    return new Promise((resolve, reject) => {
        PDFJS.getDocument(dataBuffer)
            .promise.then(document => {
                doc = document;
                ret.numpages = doc.numPages;

                let metaData;

                doc.getMetadata()
                    .then(metadata => {
                        metaData = metadata;
                        ret.info = metaData ? metaData.info : undefined;
                        ret.metadata = metaData ? metaData.metadata : undefined;

import PDFJS from 'pdfjs-dist';

// Import our styles
import 'bootstrap-colorpicker/dist/css/bootstrap-colorpicker.css';
import 'sass/styles.scss';
import 'katex/dist/katex.min.css';

import {browserHistory} from 'utils/browser_history';
import {isDevMode, setCSRFFromCookie} from 'utils/utils';
import {makeAsyncComponent} from 'components/async_load';
import store from 'stores/redux_store.jsx';
import loadRoot from 'bundle-loader?lazy!components/root';

const Root = makeAsyncComponent(loadRoot);

PDFJS.disableWorker = true;

// This is for anything that needs to be done for ALL react components.
// This runs before we start to render anything.
function preRenderSetup(callwhendone) {
    window.onerror = (msg, url, line, column, stack) => {
        if (msg === 'ResizeObserver loop limit exceeded') {
            return;
        }
        var l = {};
        l.level = 'ERROR';
        l.message = 'msg: ' + msg + ' row: ' + line + ' col: ' + column + ' stack: ' + stack + ' url: ' + url;

        const req = new XMLHttpRequest();
        req.open('POST', '/api/v4/logs');
        req.setRequestHeader('Content-Type', 'application/json');
        req.send(JSON.stringify(l));

const pdfJs = require("pdfjs-dist");
pdfJs.disableWorker = true;

const fs = require("fs");

module.exports = (filename) => {
	const book = {
		_book: undefined,

		_init: () => {
			return new Promise((resolve) => {
				fs.readFile(filename, function (err, data) {
					var data_array = new Uint8Array(data);
					pdfJs.getDocument(data_array).promise.then(function (pdf) {
						book._book = pdf;

						resolve(book);
					});