fix(firestore): array with objects with references

Fix vuejs#576

Author: posva

packages/@posva/vuefire-core/__tests__/firestore/refs-documents.spec.ts

@@ -124,6 +124,21 @@ describe('refs in documents', () => {
     })
   })
 
+  it.only('does not lose empty references in arrays of objects when updating a property', async () => {
+    const emptyItem = collection.doc()
+    await item.update({ todos: [{ ref: emptyItem }], toggle: true })
+    await bind('item', item)
+    expect(vm.item).toEqual({
+      todos: [{ ref: null }],
+      toggle: true,
+    })
+    await item.update({ toggle: false })
+    expect(vm.item).toEqual({
+      todos: [{ ref: null }],
+      toggle: false,
+    })
+  })
+
   it('keeps array of references when updating a property', async () => {
     await item.update({ a: [a, b, c, { foo: 'bar' }], toggle: true })
     await bind('item', item)

packages/@posva/vuefire-core/src/firestore/index.ts

@@ -1,4 +1,4 @@
-import { createSnapshot, extractRefs, FirestoreSerializer, FirestoreReference } from './utils'
+import { createSnapshot, extractRefs, FirestoreSerializer } from './utils'
 import { walkGet, callOnceWithArg, OperationsType } from '../shared'
 import { firestore } from 'firebase'
 

packages/@posva/vuefire-core/src/firestore/utils.ts

@@ -72,10 +72,11 @@ export function extractRefs(
         // fill existing refs into data but leave the rest empty
         for (let i = 0; i < ref.length; i++) {
           const newRef = ref[i]
+          // TODO: this only works with array of primitives but not with nested properties like objects with References
           if (newRef.path in subsByPath) data[key][i] = subsByPath[newRef.path]
         }
-        // the oldArray is in this case the same array with holes
-        recursiveExtract(ref, data[key], path + key + '.', [data[key], refs])
+        // the oldArray is in this case the same array with holes unless the array already existed
+        recursiveExtract(ref, oldDoc[key] || data[key], path + key + '.', [data[key], refs])
       } else if (isObject(ref)) {
         data[key] = {}
         recursiveExtract(ref, oldDoc[key], path + key + '.', [data[key], refs])