public api for event display

packages/__tests__/src/legacy/eventRender.js

@@ -21,7 +21,7 @@ describe('eventDidMount+eventContent', function() { // TODO: rename file
         let options = {
           eventContent(arg) {
             expect(typeof arg.event).toBe('object')
-            expect(arg.event.display).toBe('')
+            expect(arg.event.display).toBe('auto')
             expect(arg.event.start).toBeDefined()
             expect(typeof arg.view).toBe('object')
             expect(arg.isMirror).toBe(false)

packages/core/src/api/EventApi.ts

@@ -262,7 +262,7 @@ export default class EventApi {
   get allDay(): boolean { return this._def.allDay }
   get title(): string { return this._def.title }
   get url(): string { return this._def.url }
-  get display(): string { return this._def.ui.display }
+  get display(): string { return this._def.ui.display || 'auto' } // bad. just normalize the type earlier
   get startEditable(): boolean { return this._def.ui.startEditable }
   get durationEditable(): boolean { return this._def.ui.durationEditable }
   get constraint(): any { return this._def.ui.constraints[0] || null }