Nanodom.js - a very small dom manipulation library.

nanodom.js

define([], function() {

    function dom() {}
    dom.prototype             = new Array;
    dom.prototype.append      = function(element)  { element.map(function(e) { this[0].appendChild(e) }.bind(this)); return this}
    dom.prototype.remove      = function()         { this.map(function(e) {e.parentNode.removeChild(e)}); return this}
    dom.prototype.prepend     = function(element)  { element.map(function(e) { this[0].insertBefore(e, this[0].childNodes[0]) }.bind(this)); return this}
    dom.prototype.empty       = function(elements) { this.map(function(e) { e.innerHTML = ""}); return this}
    dom.prototype.addClass    = function(classes)  { this.map(function(e) { e.className += ' '+classes}); return this}
    dom.prototype.removeClass = function(classes)  {
        this.map(function(e) {
            e.className = e.className.split(' ').reduce(function(prev, cls) {
                    return (classes.indexOf(cls) < 0) ? prev.concat(cls) : prev;
            },[]).join(' ');
        })
        return this
    }

    function domify(str) { var d = document.createElement('div'); d.innerHTML = str; return d.childNodes }

    return function(selector) {
        if (selector instanceof dom) return selector
        if (selector instanceof HTMLElement) {var d = new dom(); d.push(selector); return d}
        if (typeof selector !== 'string') return
        var s, d=new dom(), c=(selector.indexOf('<') == 0);
        s = c ? domify(selector) : document.querySelectorAll(selector);
        [].slice.call(s).map(function(e) {d.push(e)})
        return d
    }
})

nanodom.test.js

define(['chai','nanodom'], function(chai, dom) {

    var assert = chai.assert;

    describe('NANODOM', function() {

        it('Can query by css selectors', function() {
            var element = dom('#mocha')
            assert.equal(element.length, 1)
        })

        it('Can create dom elements from a string', function() {
            var element = dom("<h1>eple</h1>")
            assert.equal(element[0].tagName, 'H1')
        })

        it('Can create nested dom elements from a string', function() {
            var element = dom("<div><h1>eple</h1></div>")
            assert.equal(element.length, 1)
            assert.equal(element[0].childNodes.length, 1)
        })

        it('Can create sibling dom elements from a string', function() {
            var element = dom("<li>one</li><li>two</li>")
            assert.equal(element.length, 2)
        })

        it('Can append to other dom elements', function() {
            var element = dom("<h1 class='heading'>eple</h1>")
            dom("#mocha").append(element)
            var heading = dom('.heading')
            assert.equal(heading.length, 1)
            heading.remove()
        })

        it('Can prepend to other dom elements', function() {
            var element = dom("<h1 class='heading'>eple</h1>")
            dom("#mocha").prepend(element)
            assert.equal(dom("#mocha")[0].firstChild, element[0])
            element.remove()
        })

        it('Can empty an element', function() {
            var container = dom('<ul id="epleKake"></ul>')
            container.append(dom('<li>eple</li>'))
            container.append(dom('<li>eple</li>'))
            container.append(dom('<li>eple</li>'))
            assert.equal(container[0].childNodes.length, 3)
            container.empty()
            assert.equal(container[0].childNodes.length, 0)
            container.remove()
        })

        it('Can add classes', function() {
            var element = dom('<div></div>').addClass('eple');
            dom('body').append(element)
            assert.equal(dom('.eple').length, 1)
            element.remove()
        })

        it('Can remove classes', function() {
            var element = dom('<div class="eple kanon"></div>').removeClass('kanon');
            dom('body').append(element)
            assert.equal(dom('.kanon').length, 0)
            element.remove()
        })

    })

})

What about using the "classList" attribute in addClass() and removeCass()?

e.classList.add('eple')
e.classList.remove('eple')