Given a Project Muse book id, this will fetch each chapter and merge them into a single PDF.

muse-merge.js

const fetch = require("node-fetch");
const url = require("url");
const { Parser } = require("htmlparser2");
const hummus = require("hummus");

const BOOK_ID = "66229"; // EDIT THIS

const OUTPUT_FILE = `${BOOK_ID}.pdf`;

const extractURLs = async () => {
  const baseURL = `https://muse.jhu.edu/book/${BOOK_ID}`;

  const response = await fetch(baseURL);

  if (!response.ok) {
    throw new Error("No HTML");
  }

  const html = await response.text();

  const links = [];

  let currentLink = null;

  const parser = new Parser(
    {
      onopentag: function(name, attribs) {
        if (
          name === "a" &&
          attribs.href &&
          attribs.href.match(/^\/chapter\/\d+(\/pdf)?$/)
        ) {
          currentLink = attribs.href;
        } else {
          currentLink = null;
        }
      },
      ontext: function(text) {
        if (currentLink && text.match(/\s*Download\s*/)) {
          links.push(currentLink);
        }
      },
      onclosetag: function(tagname) {
        if (tagname === "a") {
          currentLink = null;
        }
      }
    },
    { decodeEntities: true }
  );

  parser.write(html);
  parser.end();

  return links
    .map(link => url.resolve(baseURL, link))
    .map(link => link.replace(/(\/pdf)?$/, "/pdf"));
};

const buildPDF = async urls => {
  const pdfWriter = hummus.createWriter(OUTPUT_FILE);

  for (const url of urls) {
    const response = await fetch(url);

    if (!response.ok) {
      throw new Error("No PDF");
    }

    const buffer = await response.buffer();

    const inStream = new hummus.PDFRStreamForBuffer(buffer);

    const context = pdfWriter.createPDFCopyingContext(inStream);
    const pagesCount = context.getSourceDocumentParser().getPagesCount();

    console.log(url, `${pagesCount} pages`);

    if (pagesCount > 1) {
      pdfWriter.appendPDFPagesFromPDF(new hummus.PDFRStreamForBuffer(buffer), {
        type: hummus.eRangeTypeSpecific,
        specificRanges: [[1, pagesCount - 1]]
      });
    }
  }

  pdfWriter.end();
};

extractURLs()
  .then(buildPDF)
  .then(() => {
    console.log(`Written to ${OUTPUT_FILE}`);
  })
  .catch(error => {
    console.error(error);
  });

package.json

{
  "name": "muse-merge",
  "private": true,
  "license": "MIT",
  "dependencies": {
    "htmlparser2": "^3.10.1",
    "hummus": "^1.0.104",
    "node-fetch": "^2.6.0"
  }
}