feat(useFirestore): support reactive query

packages/firebase/useFirestore/index.md

@@ -8,26 +8,32 @@ Reactive [Firestore](https://firebase.google.com/docs/firestore) binding. Making
 
 ## Usage
 
-```js {7,9}
+```js {9,12,17}
+import { computed, ref } from 'vue'
 import { initializeApp } from 'firebase/app'
-import { getFirestore } from 'firebase/firestore'
+import { collection, doc, getFirestore, limit, orderBy, query } from 'firebase/firestore'
 import { useFirestore } from '@vueuse/firebase/useFirestore'
 
 const app = initializeApp({ projectId: 'MY PROJECT ID' })
 const db = getFirestore(app)
 
-const todos = useFirestore(db.collection('todos'))
+const todos = useFirestore(collection(db, 'todos'))
 
 // or for doc reference
-const user = useFirestore(db.collection('users').doc('my-user-id'))
+const user = useFirestore(doc(db, 'users', 'my-user-id'))
+
+// you can also use ref value for reactive query
+const postLimit = ref(10)
+const postsQuery = computed(() => query(collection(db, 'posts'), orderBy('createdAt', 'desc'), limit(postLimit.value)))
+const posts = useFirestore(postsQuery)
 ```
 
 ## Share across instances
 
 You can reuse the db reference by passing `autoDispose: false`
 
 ```ts
-const todos = useFirestore(db.collection('todos'), undefined, { autoDispose: false })
+const todos = useFirestore(collection(db, 'todos'), undefined, { autoDispose: false })
 ```
 
 or use `createGlobalState` from the core package
@@ -38,7 +44,7 @@ import { createGlobalState } from '@vueuse/core'
 import { useFirestore } from '@vueuse/firebase/useFirestore'
 
 export const useTodos = createGlobalState(
-  () => useFirestore(db.collection('todos')),
+  () => useFirestore(collection(db, 'todos')),
 )
 ```
 

packages/firebase/useFirestore/index.test.ts

@@ -0,0 +1,27 @@
+import { ref } from 'vue-demi'
+import { onSnapshot } from 'firebase/firestore'
+import type { Mock } from 'vitest'
+import { useFirestore } from './index'
+
+vi.mock('firebase/firestore', () => ({
+  onSnapshot: vi.fn(),
+}))
+
+describe('useFirestore', () => {
+  beforeEach(() => {
+    (onSnapshot as Mock).mockClear()
+  })
+
+  it('should call onSnapshot with document reference', () => {
+    const docRef = { path: 'users' } as any
+    useFirestore(docRef)
+    expect((onSnapshot as Mock).mock.calls[0][0]).toStrictEqual(docRef)
+  })
+
+  it('should call onSnapshot with ref value of document reference', () => {
+    const docRef = { path: 'posts' } as any
+    const refOfDocRef = ref(docRef)
+    useFirestore(refOfDocRef)
+    expect((onSnapshot as Mock).mock.calls[0][0]).toStrictEqual(docRef)
+  })
+})

packages/firebase/useFirestore/index.ts

@@ -1,6 +1,7 @@
 import type { Ref } from 'vue-demi'
-import { ref } from 'vue-demi'
+import { computed, isRef, ref, watch } from 'vue-demi'
 import type { DocumentData, DocumentReference, DocumentSnapshot, Query, QueryDocumentSnapshot } from 'firebase/firestore'
+import type { MaybeRef } from '@vueuse/shared'
 import { isDef, tryOnScopeDispose } from '@vueuse/shared'
 import { onSnapshot } from 'firebase/firestore'
 
@@ -33,24 +34,24 @@ function isDocumentReference<T>(docRef: any): docRef is DocumentReference<T> {
 }
 
 export function useFirestore<T extends DocumentData>(
-  docRef: DocumentReference<T>,
+  maybeDocRef: MaybeRef<DocumentReference<T>>,
   initialValue: T,
   options?: UseFirestoreOptions
 ): Ref<T | null>
 export function useFirestore<T extends DocumentData>(
-  docRef: Query<T>,
+  maybeDocRef: MaybeRef<Query<T>>,
   initialValue: T[],
   options?: UseFirestoreOptions
 ): Ref<T[]>
 
 // nullable initial values
 export function useFirestore<T extends DocumentData>(
-  docRef: DocumentReference<T>,
+  maybeDocRef: MaybeRef<DocumentReference<T>>,
   initialValue?: T | undefined,
   options?: UseFirestoreOptions,
 ): Ref<T | undefined | null>
 export function useFirestore<T extends DocumentData>(
-  docRef: Query<T>,
+  maybeDocRef: MaybeRef<Query<T>>,
   initialValue?: T[],
   options?: UseFirestoreOptions
 ): Ref<T[] | undefined>
@@ -62,22 +63,27 @@ export function useFirestore<T extends DocumentData>(
  * @see https://vueuse.org/useFirestore
  */
 export function useFirestore<T extends DocumentData>(
-  docRef: FirebaseDocRef<T>,
+  maybeDocRef: MaybeRef<FirebaseDocRef<T>>,
   initialValue: any = undefined,
   options: UseFirestoreOptions = {},
 ) {
   const {
-
     errorHandler = (err: Error) => console.error(err),
     autoDispose = true,
   } = options
 
-  if (isDocumentReference<T>(docRef)) {
+  const refOfDocRef = isRef(maybeDocRef) ? maybeDocRef : computed(() => maybeDocRef)
+
+  if (isDocumentReference<T>(refOfDocRef.value)) {
     const data = ref(initialValue) as Ref<T | null | undefined>
+    let close = () => { }
 
-    const close = onSnapshot(docRef, (snapshot) => {
-      data.value = getData(snapshot) || null
-    }, errorHandler)
+    watch(refOfDocRef, (docRef) => {
+      close()
+      close = onSnapshot(docRef as DocumentReference<T>, (snapshot) => {
+        data.value = getData(snapshot) || null
+      }, errorHandler)
+    }, { immediate: true })
 
     tryOnScopeDispose(() => {
       close()
@@ -87,10 +93,14 @@ export function useFirestore<T extends DocumentData>(
   }
   else {
     const data = ref(initialValue) as Ref<T[] | undefined>
+    let close = () => { }
 
-    const close = onSnapshot(docRef, (snapshot) => {
-      data.value = snapshot.docs.map(getData).filter(isDef)
-    }, errorHandler)
+    watch(refOfDocRef, (docRef) => {
+      close()
+      close = onSnapshot(docRef as Query<T>, (snapshot) => {
+        data.value = snapshot.docs.map(getData).filter(isDef)
+      }, errorHandler)
+    }, { immediate: true })
 
     if (autoDispose) {
       tryOnScopeDispose(() => {