message: Tested Back Link with default value
diff: @@ -59,6 +59,19 @@ describe('NavigationBackLinkTest', function () {
  })
  });
  + describe('Without State Navigator Navigation Back Link', function () {
  + it('should render', function(){
  + var wrapper = mount(
  + <NavigationBackLink distance={1}>
  + link text
  + </NavigationBackLink>
  + );
  + var link = wrapper.find('a');
  + assert.equal(link.prop('href'), null);
  + assert.equal(link.prop('children'), 'link text');
  + })
  + });
  +
  describe('Invalid Navigation Back Link', function () {
  it('should render', function(){
  var stateNavigator = new StateNavigator([
  @@ -428,6 +441,34 @@ describe('NavigationBackLinkTest', function () {
  })
  });
  + describe('Context Across Crumbs Crumb Trail Navigate Navigation Back Link', function () {
  + it('should update', function(){
  + var stateNavigator = new StateNavigator([
  + { key: 's0', route: 'r0' },
  + { key: 's1', route: 'r1', trackCrumbTrail: true }
  + ]);
  + stateNavigator.navigate('s0');
  + stateNavigator.navigate('s1');
  + var wrapper = mount(
  + <NavigationBackLink
  + acrossCrumbs={true}
  + distance={1}>
  + link text
  + </NavigationBackLink>,
  + {
  + context: { stateNavigator: stateNavigator },
  + childContextTypes: { stateNavigator: () => {}}
  + }
  + );
  + var link = wrapper.find('a');
  + assert.equal(link.prop('href'), '#/r0');
  + stateNavigator.navigate('s1');
  + wrapper.update();
  + link = wrapper.find('a');
  + assert.equal(link.prop('href'), '#/r1?crumb=%2Fr0');
  + })
  + });
  +
  describe('Click Custom Href Navigation Back Link', function () {
  it('should navigate', function(){
  var stateNavigator = new StateNavigator([
  