Don't lose data in Tray on state update

refs ADMIN-752

Test plan
- Open the update tray while the planner is
  still loading opportunities
- (Very quickly) type something in the title
  field
- Wait a few seconds for everything to finish
  loading and ensure the title is not lost
  and ensure the date field doesn't error
- Focus is still being lost at final planner
  render, further ticket needed

Change-Id: I8366d13959e1285b930e5ee434d616575a8b3daa
Reviewed-on: https://gerrit.instructure.com/140377
Reviewed-by: Jeremy Stanley <jeremy@instructure.com>
Tested-by: Jenkins
QA-Review: Deepeeca Soundarrajan <dsoundarrajan@instructure.com>
Product-Review: Mysti Sadler <mysti@instructure.com>

packages/canvas-planner/src/components/UpdateItemTray/__tests__/UpdateItemTray.spec.js

@@ -43,6 +43,13 @@ it('renders the item to update if provided', () => {
   expect(wrapper).toMatchSnapshot();
 });
 
+it("doesn't re-render unless new item is provided", () => {
+  const wrapper = shallow(<UpdateItemTray {...defaultProps} />)
+  const newProps = {...defaultProps, locale: 'fr'}
+  wrapper.setProps(newProps)
+  expect(wrapper.find('DateInput').props()['messages'].length).toBe(0)
+})
+
 it('renders Add To Do header when creating a new to do', () => {
   const wrapper = mount(
     <UpdateItemTray {...defaultProps} />

packages/canvas-planner/src/components/UpdateItemTray/index.js

@@ -60,8 +60,10 @@ export class UpdateItemTray extends Component {
   }
 
   componentWillReceiveProps (nextProps) {
-    const updates = this.getNoteUpdates(nextProps);
-    this.setState({updates}, this.updateMessages);
+    if (nextProps.noteItem) {
+      const updates = this.getNoteUpdates(nextProps);
+      this.setState({updates}, this.updateMessages);
+    }
   }
 
   getNoteUpdates (props) {