foolish number check fix, add test

Author: 0mkara

src/js/TreeNode.js

@@ -195,7 +195,7 @@ class TreeNode extends React.Component {
         } = this.props;
 
         const clickable = onClick.toString() !== TreeNode.defaultProps.onClick.toString();
-        const inputId = `${treeId}-${Number.isNaN(value) ? value : value.split(' ').join('_')}`;
+        const inputId = `${treeId}-${Number.isInteger(value) ? value : value.split(' ').join('_')}`;
 
         const render = [(
             <label key={0} htmlFor={inputId}>

test/TreeNode.js

@@ -36,6 +36,15 @@ describe('<TreeNode />', () => {
             assert.equal('planets-jupiter', wrapper.find('label').prop('htmlFor'));
             assert.equal('planets-jupiter', wrapper.find('label NativeCheckbox').prop('id'));
         });
+
+        it('should render a label associated with a checkbox given integer value', () => {
+            const wrapper = shallow(
+                <TreeNode {...baseProps} treeId="planets" value={0} />,
+            );
+
+            assert.equal('planets-0', wrapper.find('label').prop('htmlFor'));
+            assert.equal('planets-0', wrapper.find('label NativeCheckbox').prop('id'));
+        });
     });
 
     describe('checked', () => {