fix: nested refs

Author: posva

playground/src/firebase.ts

@@ -22,7 +22,7 @@ export function createFirebaseApp() {
   const firestore = getFirestore(firebaseApp)
   const analytics = getAnalytics(firebaseApp)
 
-  connectFirestoreEmulator(firestore, 'localhost', 8080)
+  // connectFirestoreEmulator(firestore, 'localhost', 8080)
 
   return { firebaseApp, firestore, analytics }
 }

playground/src/pages/config.vue

@@ -6,11 +6,11 @@ import { useFirestore } from '@/firebase'
 
 const db = useFirestore()
 const configRef = doc(db, 'configs', 'jORwjIykFo2NmkdzTkhU')
-const itemRef = doc(db, 'tests', 'item')
+// const itemRef = doc(db, 'tests', 'item')
 
 const config = ref()
-firestoreBind(config, itemRef)
-// firestoreBind(config, configRef)
+// firestoreBind(config, itemRef)
+firestoreBind(config, configRef)
 </script>
 
 <template>

src/firestore/utils.ts

@@ -4,15 +4,20 @@ import type {
   CollectionReference,
   DocumentSnapshot,
   DocumentData,
+  GeoPoint,
 } from 'firebase/firestore'
 import { isTimestamp, isObject, isDocumentRef, TODO } from '../shared'
 
 export type FirestoreReference = Query | DocumentReference | CollectionReference
 
 // TODO: fix type not to be any
-export function createSnapshot(doc: DocumentSnapshot): TODO {
+export function createSnapshot<T = DocumentData>(
+  doc: DocumentSnapshot<T>
+): { id: string } & T {
   // TODO: it should create a deep copy instead because otherwise we will modify internal data
   // defaults everything to false, so no need to set
+  // FIXME: can this be called when the document doesn't exist?
+  // @ts-expect-error
   return Object.defineProperty(doc.data() || {}, 'id', { value: doc.id })
 }
 
@@ -54,18 +59,18 @@ export function extractRefs(
 
     // recursively traverse doc to copy values and extract references
     for (const key in doc) {
-      const ref: TODO = doc[key]
+      const ref: unknown = doc[key]
       if (
         // primitives
         ref == null ||
         // Firestore < 4.13
         ref instanceof Date ||
         isTimestamp(ref) ||
-        (ref.longitude && ref.latitude) // GeoPoint
+        isGeoPoint(ref)
       ) {
         data[key] = ref
       } else if (isDocumentRef(ref)) {
-        // allow values to be null (like non-existant refs)
+        // allow values to be null (like non-existent refs)
         // TODO: better typing since this isObject shouldn't be necessary but it doesn't work
         data[key] =
           typeof oldDoc === 'object' &&
@@ -104,3 +109,7 @@ export function extractRefs(
 
   return dataAndRefs
 }
+
+function isGeoPoint(value: unknown): value is GeoPoint {
+  return isObject(value) && 'latitude' in value && 'longitude' in value
+}

src/shared.ts

@@ -52,7 +52,7 @@ export function walkSet<T>(
  * Checks if a variable is an object
  * @param o
  */
-export function isObject(o: any): o is object {
+export function isObject(o: any): o is Record<any, unknown> {
   return o && typeof o === 'object'
 }
 
@@ -69,9 +69,11 @@ export function isTimestamp(o: any): o is Date {
  * @param o
  */
 export function isDocumentRef(o: any): o is DocumentReference {
-  return o && o.onSnapshot
+  return isObject(o) && o.type === 'document'
 }
 
+type ReferenceType = 'collection' | 'document' | 'query'
+
 /**
  * Wraps a function so it gets called only once
  * @param fn Function to be called once
@@ -81,8 +83,7 @@ export function callOnceWithArg<T, K>(
   fn: (arg: T) => K,
   argFn: () => T
 ): () => K | undefined {
-  /** @type {boolean | undefined} */
-  let called = false
+  let called: boolean | undefined
 
   return (): K | undefined => {
     if (!called) {