fix(core): drop raw refs when updating docs

Closes vuejs#831

Author: posva

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

@@ -80,6 +80,17 @@ describe('refs in documents', () => {
     expect(vm.arr).toEqual({ refs: [b.path, c.path] })
   })
 
+  it('keeps correct elements in array of references when removing in the middle', async () => {
+    const arr = collection.doc()
+    vm.arr = null
+
+    await arr.update({ refs: [a, b, c] })
+    await bind('arr', arr, { maxRefDepth: 0 })
+    await arr.update({ refs: [a, c] })
+
+    expect(vm.arr).toEqual({ refs: [a.path, c.path] })
+  })
+
   it('binds refs on documents', async () => {
     // create an empty doc and update using the ref instead of plain data
     await item.update({ ref: c })
@@ -124,7 +135,7 @@ describe('refs in documents', () => {
     })
   })
 
-  it.only('does not lose empty references in arrays of objects when updating a property', async () => {
+  it('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)

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

@@ -64,7 +64,14 @@ export function extractRefs(
       } else if (isDocumentRef(ref)) {
         // allow values to be null (like non-existant refs)
         // TODO: better typing since this isObject shouldn't be necessary but it doesn't work
-        data[key] = typeof oldDoc === 'object' && key in oldDoc ? oldDoc[key] : ref.path
+        data[key] =
+          typeof oldDoc === 'object' &&
+          key in oldDoc &&
+          // only copy refs if they were refs before
+          // https://github.com/vuejs/vuefire/issues/831
+          typeof oldDoc[key] != 'string'
+            ? oldDoc[key]
+            : ref.path
         // TODO: handle subpathes?
         refs[path + key] = ref
       } else if (Array.isArray(ref)) {