feat(refs): unbind removed refs on documents

Author: posva

src/index.js

@@ -13,6 +13,12 @@ function subscribeToRefs ({
   resolve
 }) {
   const refKeys = Object.keys(refs)
+  const missingKeys = Object.keys(subs).filter(refKey => refKeys.indexOf(refKey) < 0)
+  // unbind keys that are no longer there
+  missingKeys.forEach(refKey => {
+    subs[refKey].unbind()
+    delete subs[refKey]
+  })
   if (!refKeys.length) return resolve()
   // TODO check if no ref is missing
   // TODO max depth param, default to 1?
@@ -92,6 +98,8 @@ function bindCollection ({
       array.splice(oldIndex, 1)
       array.splice(newIndex, 0, createSnapshot(doc))
       // TODO replace listeners of nested refs
+      const subs = arraySubs.splice(oldIndex, 1)[0]
+      arraySubs.splice(newIndex, 0, subs)
     },
     removed: ({ oldIndex }) => {
       array.splice(oldIndex, 1)

test/helpers/mock.js

@@ -71,6 +71,13 @@ export class DocumentReference {
     this.cb(new DocumentSnapshot(null, this.id, this.data, true))
     return this.collection._modify(this.id, this.data)
   }
+
+  async set (data) {
+    this.data = { ...data }
+    this.exists = true
+    this.cb(new DocumentSnapshot(null, this.id, this.data, true))
+    return this.collection._modify(this.id, this.data)
+  }
 }
 
 class CollectionReference {

test/refs-documents.spec.js

@@ -309,3 +309,49 @@ test('unbinds when a ref is replaced', async () => {
   cSpy.mockRestore()
   dSpy.mockRestore()
 })
+
+test('unbinds removed properties', async () => {
+  const a = db.collection().doc()
+  const b = db.collection().doc()
+  const unbindSpy = spyUnbind(a)
+  const callbackSpy = spyOnSnapshotCallback(a)
+  const onSnapshotSpy = spyOnSnapshot(a)
+
+  const item = db.collection().doc()
+  await a.update({ isA: true })
+  await b.update({ isB: true })
+  await item.update({ a })
+
+  expect(unbindSpy).toHaveBeenCalledTimes(0)
+  expect(callbackSpy).toHaveBeenCalledTimes(0)
+  expect(onSnapshotSpy).toHaveBeenCalledTimes(0)
+  await vm.$bind('item', item)
+  expect(vm.item).toEqual({
+    a: {
+      isA: true
+    }
+  })
+
+  expect(unbindSpy).toHaveBeenCalledTimes(0)
+  expect(callbackSpy).toHaveBeenCalledTimes(1)
+  expect(onSnapshotSpy).toHaveBeenCalledTimes(1)
+
+  await item.set({ b })
+  await a.update({ newA: true })
+  // NOTE see #1
+  await delay(5)
+
+  expect(vm.item).toEqual({
+    b: {
+      isB: true
+    }
+  })
+
+  expect(unbindSpy).toHaveBeenCalledTimes(1)
+  expect(callbackSpy).toHaveBeenCalledTimes(1)
+  expect(onSnapshotSpy).toHaveBeenCalledTimes(1)
+
+  unbindSpy.mockRestore()
+  callbackSpy.mockRestore()
+  onSnapshotSpy.mockRestore()
+})