feat(firestore): force once option during SSR

src/firestore/index.ts

@@ -23,6 +23,7 @@ import {
 import { useFirebaseApp } from '../app'
 import {
   isDocumentRef,
+  isSSR,
   noop,
   OperationsType,
   ResetOption,
@@ -67,6 +68,10 @@ export function _useFirestoreRef(
   const options = Object.assign({}, firestoreOptionsDefaults, localOptions)
   const initialSourceValue = unref(docOrCollectionRef)
 
+  if (isSSR()) {
+    options.once = true
+  }
+
   const data = options.target || ref<unknown | null>()
   // set the initial value from SSR even if the ref comes from outside
   data.value = getInitialValue(initialSourceValue, options.ssrKey, data.value)

src/shared.ts

@@ -9,6 +9,7 @@ import {
   Timestamp,
 } from 'firebase/firestore'
 import { StorageReference } from 'firebase/storage'
+import { inject, ssrContextKey } from 'vue-demi'
 import type { Ref, ShallowRef } from 'vue-demi'
 
 export const noop = () => {}
@@ -272,3 +273,17 @@ export type _Mutable<T> = {
 export interface _ResolveRejectFn {
   (value: unknown): void
 }
+
+/**
+ * Check if we are in an SSR environment within a composable. Used to force `options.once` to `true`.
+ *
+ * @internal
+ */
+export function isSSR(): boolean {
+  return (
+    !!inject(ssrContextKey, null) ||
+    //
+    // @ts-expect-error
+    import.meta.env?.SSR
+  )
+}