Merge pull request #17744 from atom/fix-17535

Teach Pane to always look for a pane item's onDidTerminatePendingState function

spec/pane-spec.js

@@ -219,6 +219,34 @@ describe('Pane', () => {
       runs(() => expect(eventOrder).toEqual(['add', 'remove']))
     })
 
+    it('subscribes to be notified when item terminates its pending state', () => {
+      const fakeDisposable = { dispose: () => {} }
+      const spy = jasmine.createSpy('onDidTerminatePendingState').andReturn((fakeDisposable))
+
+      const pane = new Pane(paneParams({items: []}))
+      const item = {
+        getTitle: () => '',
+        onDidTerminatePendingState: spy
+      }
+      pane.addItem(item)
+
+      expect(spy).toHaveBeenCalled()
+    })
+
+    it('subscribes to be notified when item is destroyed', () => {
+      const fakeDisposable = { dispose: () => {} }
+      const spy = jasmine.createSpy('onDidDestroy').andReturn((fakeDisposable))
+
+      const pane = new Pane(paneParams({items: []}))
+      const item = {
+        getTitle: () => '',
+        onDidDestroy: spy
+      }
+      pane.addItem(item)
+
+      expect(spy).toHaveBeenCalled()
+    })
+
     describe('when using the old API of ::addItem(item, index)', () => {
       beforeEach(() => spyOn(Grim, 'deprecate'))
 

src/pane.js

@@ -614,15 +614,15 @@ class Pane {
 
     if (this.items.includes(item)) return
 
+    const itemSubscriptions = new CompositeDisposable()
+    this.subscriptionsPerItem.set(item, itemSubscriptions)
     if (typeof item.onDidDestroy === 'function') {
-      const itemSubscriptions = new CompositeDisposable()
       itemSubscriptions.add(item.onDidDestroy(() => this.removeItem(item, false)))
-      if (typeof item.onDidTerminatePendingState === 'function') {
-        itemSubscriptions.add(item.onDidTerminatePendingState(() => {
-          if (this.getPendingItem() === item) this.clearPendingItem()
-        }))
-      }
-      this.subscriptionsPerItem.set(item, itemSubscriptions)
+    }
+    if (typeof item.onDidTerminatePendingState === 'function') {
+      itemSubscriptions.add(item.onDidTerminatePendingState(() => {
+        if (this.getPendingItem() === item) this.clearPendingItem()
+      }))
     }
 
     this.items.splice(index, 0, item)