JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://rawgit.com/mrdoob/three.js/master/build/three.js"></script>

JavaScript

var scene = new THREE.Scene();
            var camera = new THREE.PerspectiveCamera( 75, window.innerWidth / window.innerHeight, 0.1, 1000 );

            var renderer = new THREE.WebGLRenderer();
renderer.setSize( window.innerWidth, window.innerHeight );


            document.body.appendChild( renderer.domElement );
            var material = new THREE.MeshBasicMaterial({
                                color: 0x0000ff
                            });

            var radius = 5;
            var segments = 32;

            var circleGeometry = new THREE.CircleGeometry( radius, segments );              
            var circle = new THREE.Mesh( circleGeometry, material );
           /*CREATE EDGES*/
            var edges = new THREE.EdgesHelper( circle, 0x00ff0f );
            /*IT NEEDS TO CONVERT FROM BUFFER GEOMETRY TO GEOMETRY TO USE GEOMETRY MERGE FUNCTION*/
            var edgeGeometry = new THREE.Geometry().fromBufferGeometry(edges.geometry);
           /*HERE IS THE PROBLEM*/
            circleGeometry.merge(edgeGeometry);

            scene.add( circle );

            camera.position.z = 15;

            function render() {
                requestAnimationFrame( render );
                renderer.render( scene, camera );
            }
            render();