How to use the iconv-lite.skipDecodeWarning function in iconv-lite

Parser.prototype.parseFile = function(filename, encoding) {
    var self = this;

    if (typeof(encoding) === 'undefined')
        encoding = 'utf8';

    app.log.debug('inspect file: ' + filename);

    self.filename = filename;
    self.extension = path.extname(filename).toLowerCase();
    // TODO: Not sure if this is correct. Without skipDecodeWarning we got string errors
    // https://github.com/apidoc/apidoc-core/pull/25
    var fileContent = fs.readFileSync(filename, { encoding: 'binary' });
    iconv.skipDecodeWarning = true;
    self.src = iconv.decode(fileContent, encoding);
    app.log.debug('size: ' + self.src.length);

    // unify line-breaks
    self.src = self.src.replace(/\r\n/g, '\n');

    self.blocks = [];
    self.indexApiBlocks = [];

    // determine blocks
    self.blocks = self._findBlocks();
    if (self.blocks.length === 0)
        return;

    app.log.debug('count blocks: ' + self.blocks.length);

'use strict';

const fs = require('fs');
const os = require('os');
const iconv = require('iconv-lite');
const pty = require('node-pty');
const stripAnsi = require('strip-ansi');

iconv.skipDecodeWarning = true;

module.exports = io => {
    io.on('connection', socket => {
        /**
         * Usuário se conectou então nós criamos o terminal e definimos a trava (listen)
         */
        console.log('Usuário conectado!');

        let listen = false;
        const shell_location = `${__dirname}/runtime/dist`;
        const shell = `${shell_location}/portugol-runtime` + (os.platform() === 'win32' ? '.exe' : '');
        let term;
        console.log(`Iniciando em ${shell}`);

        try {
            term = pty.spawn(shell, [''], {

var AbstractScraper = require("./AbstractScraper"),
    config = require("../config"),
    request = require("request-promise"),
    cheerio = require("cheerio"),
    urlLib = require("url"),
    moment = require("moment"),
    iconv = require("iconv-lite");

iconv.skipDecodeWarning = true;
module.exports = class ImmonetScraper extends AbstractScraper {
    constructor(db) {
        super(db, "immonet");
        this.cookieJar = request.jar();
    }
    _isAngebot(tableRow) {
        return true;
    }
    _isVermietetByTableRow() {
        return false; //unfortunately we cannot get this from the table row, we need to update it via updateItems
    }
    _getNextPage(url, $) {
        const nextLink = $(".pagination-wrapper+a[href]");
        if (nextLink.length > 0) {
            return urlLib.resolve(url, nextLink.attr("href"));
        } else {

var AbstractScraper = require("./AbstractScraper"),
  config = require("../config"),
  request = require("request-promise"),
  cheerio = require("cheerio"),
  urlLib = require("url"),
  moment = require("moment"),
  iconv = require("iconv-lite");

iconv.skipDecodeWarning = true;

module.exports = class WgGesuchtScraper extends AbstractScraper {
  constructor(db) {
    super(db, "studentenWg");
    this.cookieJar = request.jar();
  }
  _isAngebot(tableRow) {
    var id = tableRow.attr("id");
    if (id != null && id.indexOf("wg-ergrow") === 0) {
      return true;
    }
    return false;
  }
  _isVermietetByTableRow() {
    return false; //unfortunately we cannot get this from the table row, we need to update it via updateItems
  }

fn: function (buf, code, sys) {
      const iconv = require('iconv-lite')
      iconv.skipDecodeWarning = true
      return iconv.decode(Buffer.from(buf), code)
    }
  },