forceEventDuration works with external events. fixes #4597

src/interaction/interactions-external/ExternalElementDragging.ts

@@ -216,7 +216,7 @@ function computeEventForDateSpan(dateSpan: DateSpan, dragMeta: DragMeta, calenda
     defProps,
     dragMeta.sourceId,
     dateSpan.allDay,
-    Boolean(dragMeta.duration), // hasEnd
+    calendar.opt('forceEventDuration') || Boolean(dragMeta.duration), // hasEnd
     calendar
   )
 

tests/automated/event-drag/from-external.js

@@ -0,0 +1,55 @@
+import { Draggable } from '@fullcalendar/interaction'
+import { getDayEl } from '../view-render/DayGridRenderUtils'
+
+describe('external event dragging', function() {
+  var $dragEl
+  var thirdPartyDraggable
+
+  beforeEach(function() {
+    $dragEl = $('<div class="drag">yo</div>')
+      .css({
+        width: 200,
+        background: 'blue',
+        color: 'white'
+      })
+      .appendTo('body')
+  })
+
+  afterEach(function() {
+    if (thirdPartyDraggable) {
+      thirdPartyDraggable.destroy()
+    }
+    $dragEl.remove()
+    $dragEl = null
+  })
+
+
+  describe('with forceEventDuration', function() {
+    pushOptions({
+      forceEventDuration: true,
+      defaultEventDuration: '1:30'
+    })
+
+    it('should yield an event with an end', function(done) {
+      initCalendar({
+        defaultView: 'dayGridMonth',
+        defaultDate: '2019-04-01',
+        droppable: true,
+        defaultAllDayEventDuration: { days: 2 },
+        eventReceive(arg) {
+          expect(arg.event.end).toEqualDate('2019-04-04')
+          done()
+        }
+      })
+
+      thirdPartyDraggable = new Draggable($dragEl[0], {
+        eventData: {}
+      })
+
+      $dragEl.simulate('drag', {
+        end: getDayEl('2019-04-02')
+      })
+    })
+  })
+
+})