index.js

var PDFJS = null;

function render_page(pageData) {
  let render_options = {
    normalizeWhitespace: false,
    disableCombineTextItems: false,
  };

  return pageData.getTextContent(render_options).then(function (textContent) {
    let lastY,
      text = "";
    for (let item of textContent.items) {
      if (lastY == item.transform[5] || !lastY) {
        text += item.str;
      } else {
        text += "\n" + item.str;
      }
      lastY = item.transform[5];
    }
    return text;
  });
}

const DEFAULT_OPTIONS = {
  pagerender: render_page,
  max: 0,
  version: "v1.10.100",
};

async function PDF(dataBuffer, options) {
  var isDebugMode = false;

  let ret = {
    numpages: 0,
    numrender: 0,
    info: null,
    metadata: null,
    pageTextArray: [],
    text: "",
    version: null,
  };

  if (typeof options == "undefined") options = DEFAULT_OPTIONS;
  if (typeof options.pagerender != "function")
    options.pagerender = DEFAULT_OPTIONS.pagerender;
  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;

  PDFJS = PDFJS ? PDFJS : require(`./pdf.js/${options.version}/build/pdf.js`);
  ret.version = PDFJS.version;
  PDFJS.disableWorker = true;
  let doc = await PDFJS.getDocument(dataBuffer);
  ret.numpages = doc.numPages;

  let metaData = await doc.getMetadata().catch(function (err) {
    return null;
  });

  ret.info = metaData ? metaData.info : null;
  ret.metadata = metaData ? metaData.metadata : null;

  let counter = options.max <= 0 ? doc.numPages : options.max;
  counter = counter > doc.numPages ? doc.numPages : counter;

  ret.text = "";
  ret.pageTextArray = [];

  for (var i = 1; i <= counter; i++) {
    let pageText = await doc
      .getPage(i)
      .then((pageData) => options.pagerender(pageData))
      .catch((err) => {
        // todo log err using debug
        debugger;
        return "";
      });

    ret.text = `${ret.text}\n\n${pageText}`;
    ret.pageTextArray.push(`${pageText}`);
  }

  ret.numrender = counter;
  doc.destroy();

  return ret;
}

module.exports = PDF;