React 0.14.7: `<option value="">empty</option>` emits empty string on change
http://jsbin.com/pisita/10/edit?html,js,console,output
React 15.0.0-rc.1`<option value="">empty</option>` emits string with value "empty" on change
http://jsbin.com/bemaze/12/edit?html,js,console,output
This is because React 15.0.0-rc.1 cuts off `value=""` from option tag

it('should allow numbers as children', function() {
    spyOn(console, 'error');
    var node = ReactDOM.findDOMNode(renderTextarea(<textarea>{17}</textarea>));
    expect(console.error.argsForCall.length).toBe(1);
    expect(node.value).toBe('17');
  });
  it('should allow booleans as children', function() {
    spyOn(console, 'error');
    var node = ReactDOM.findDOMNode(renderTextarea(<textarea>{false}</textarea>));
    expect(console.error.argsForCall.length).toBe(1);
    expect(node.value).toBe('false');
  });
  it('should allow objects as children', function() {
    spyOn(console, 'error');
    var obj = {
      toString: function() {
        return 'sharkswithlasers';
      },
    };
    var node = ReactDOM.findDOMNode(renderTextarea(<textarea>{obj}</textarea>));
    expect(console.error.argsForCall.length).toBe(1);
    expect(node.value).toBe('sharkswithlasers');
  });
  it('should throw with multiple or invalid children', function() {
    spyOn(console, 'error');
    expect(function() {
      ReactTestUtils.renderIntoDocument(
        <textarea>{'hello'}{'there'}</textarea>
      );
    }).toThrow();