Ace Editor

http://www.coding-ideas.de/2018/03/20/integrating-ace-editor-to-extjs
https://endertech.com/blog/setting-inline-js-code-editor
https://github.com/ajaxorg/ace/wiki/Configuring-Ace

var editor = ace.edit("editor");
editor.setTheme("ace/theme/twilight");
editor.getSession().setMode("ace/mode/javascript");

var html_editor = ace.edit('html_editor');

html_editor.$blockScrolling = Infinity;
html_editor.getSession().setTabSize(2);
html_editor.getSession().setUseSoftTabs(false);

var editorFirst = ace.edit("editorFirst");
var editorSecond= ace.edit("editorSecond");
setupEditor();

function setupEditor() {
    editorFirst.setTheme("ace/theme/eclipse");
    editorFirst.getSession().setMode("ace/mode/javascript");
    editorFirst.setShowPrintMargin(false);
    editorFirst.setHighlightActiveLine(true);
    editorFirst.resize();
    editorFirst.setBehavioursEnabled(true);
    editorFirst.getSession().setUseWrapMode(true);
    document.getElementById('editorFirst').style.fontSize = '14px';

    editorSecond.setTheme("ace/theme/eclipse");
    editorSecond.getSession().setMode("ace/mode/javascript");
    editorSecond.setShowPrintMargin(false);
    editorSecond.setHighlightActiveLine(true);
    editorSecond.resize();
    editorSecond.setBehavioursEnabled(true);
    editorReducer.getSession().setUseWrapMode(true);
    document.getElementById('editorSecond').style.fontSize = '14px';
}