[fixed] Link module adds extra space

modules/Link.js

@@ -81,8 +81,8 @@ export var Link = React.createClass({
 
  // ignore if rendered outside of the context of a router, simplifies unit testing
  if (router && router.isActive(to, query)) {
- if (props.activeClassName)
- props.className += ` ${props.activeClassName}`;
+ if (props.activeClassName) 
+ props.className += props.className !== '' ? ` ${props.activeClassName}` : props.activeClassName;
 
  if (props.activeStyle)
  Object.assign(props.style, props.activeStyle);

modules/__tests__/Link-test.js

@@ -114,6 +114,50 @@ describe('A <Link>', function () {
  });
  });
 
+ describe('when its route is active and className is empty', function () {
+ it('it shouldn\'t have an active class', function (done) {
+ var LinkWrapper = React.createClass({
+ render() {
+ return (
+ <div>
+ <Link to="hello" className="dontKillMe" activeClassName="">Link</Link>
+ {this.props.children}
+ </div>
+ );
+ }
+ });
+
+ var a, steps = [
+ function () {
+ a = div.querySelector('a');
+ expect(a.className).toEqual('dontKillMe');
+ this.transitionTo('hello');
+ },
+ function () {
+ expect(a.className).toEqual('dontKillMe');
+ done();
+ }
+ ];
+
+ function execNextStep() {
+ try {
+ steps.shift().apply(this, arguments);
+ } catch (error) {
+ done(error);
+ }
+ }
+
+ render((
+ <Router history={new MemoryHistory('/goodbye')} onUpdate={execNextStep}>
+ <Route path="/" component={LinkWrapper}>
+ <Route path="goodbye" component={Goodbye}/>
+ <Route path="hello" component={Hello}/>
+ </Route>
+ </Router>
+ ), div, execNextStep);
+ });
+ });
+
  describe('when its route is active', function () {
  it('has its activeClassName', function (done) {
  var LinkWrapper = React.createClass({