index.js

"use strict";

const PLUGIN_NAME = 'gulp-feather';

const PluginError = require('plugin-error');
const through = require('through2');
const { JSDOM } = require('jsdom');
const { replace } = require('feather-icons');

function emulateBrowser(dom, execFunc) {
  const savedVariables = new Map();

  // override document and DOMParser
  if (typeof global.document !== 'undefined') {
    savedVariables.set('document', global.document);
  }
  global.document = dom.window.document;
  if (typeof global.DOMParser !== 'undefined') {
    savedVariables.set('DOMParser', global.DOMParser);
  }
  global.DOMParser = dom.window.DOMParser;

  execFunc();
  
  // restore overrided variables
  if (savedVariables.has('document')) {
    global.document = savedVariables.get('document');
  }
  if (savedVariables.has('DOMParser')) {
    global.DOMParser = savedVariables.get('DOMParser');
  }
}

module.exports = (attrs = {}) => through.obj(function (file, encoding, cb) {


  if (file.isNull()) {
    // nothing to do
    return cb(null, file);
  }

  if (file.isStream()) {
    // might support stream in the future
    const err = new PluginError(PLUGIN_NAME, 'Streams not supported!');
    this.emit('error', err);
    return cb(err);
  }

  if (file.isBuffer()) {
    // create dom from html file
    const dom = new JSDOM(file.contents, { runScripts: 'outside-only' });

    // replace feathericons in an emulated browser environment
    emulateBrowser(dom, ()=>replace(attrs));

    // output to file contents
    const HTMLResult = dom.serialize();
    if (file.contents.length < HTMLResult.length) {
      const buf = Buffer.from(HTMLResult, encoding);
      file.contents = buf;
    } else {
      file.contents.write(HTMLResult, encoding);
    }

    return cb(null, file);
  }

  // this should be unreachable
  const err = new PluginError(PLUGIN_NAME, 'Unexpected type of input');
  this.emit('error', err);
  return cb(err);
});