table can determine column headers from just the data [#153234166]

Signed-off-by: Reid Mitchell <rmitchell@pivotal.io>

Author: Ming Xiao

spec/pivotal-ui-react/table/plugins/sorting_spec.js

@@ -2,19 +2,40 @@ import '../../spec_helper';
 import {Table, withSorting} from '../../../../src/react/table';
 
 describe('withSorting', () => {
+  let data, ComposedTable;
   beforeEach(() => {
-    const columns = [{
-      attribute: 'attr1'
-    }, {
-      attribute: 'attr2', displayName: 'Display2'
-    }];
-    const data = [{
+    data = [{
       attr1: 'row1-value1', attr2: 'row1-value2'
     }, {
       attr1: 'row2-value1', attr2: 'row2-value2'
     }];
+    ComposedTable = withSorting(Table);
+  });
+
+  describe('with columns', () => {
+    beforeEach(() => {
+      const columns = [{
+        attribute: 'attr1'
+      }, {
+        attribute: 'attr2', displayName: 'Display2'
+      }];
+
+      ReactDOM.render(<ComposedTable {...{columns, data, className: 'sorting-table'}}/>, root);
+    });
 
-    const ComposedTable = withSorting(Table);
-    ReactDOM.render(<ComposedTable {...{columns, data}}/>, root);
+    it('renders', () => {
+      expect('.sorting-table').toExist();
+    });
   });
+
+  describe('without columns', () => {
+    beforeEach(() => {
+      ReactDOM.render(<ComposedTable {...{data, className: 'sorting-table'}}/>, root);
+    });
+
+    it('renders', () => {
+      expect('.sorting-table').toExist();
+    });
+  });
+
 });