[firestore] Consolidate some code

Author: chrisbianca

firestore/README.md

@@ -126,9 +126,9 @@ The `useCollectionData` hook takes the following parameters:
 
 - `query`: (optional) `firestore.Query` for the data you would like to load
 - `options`: (optional) `Object` with the following parameters:
+  - `initialValue`: (optional) the initial value returned by the hook, until data from the firestore query has loaded
   - `snapshotListenOptions`: (optional) `firestore.SnapshotListenOptions` to customise how the collection is loaded
   - `snapshotOptions`: (optional) `firestore.SnapshotOptions` to customise how data is retrieved from snapshots
-  - `initialValue`: (optional) the initial value returned by the hook, until data from the firestore query has loaded
 
 Returns:
 
@@ -154,8 +154,8 @@ The `useCollectionDataOnce` hook takes the following parameters:
 - `options`: (optional) `Object` with the following parameters:
   - `getOptions`: (optional) `Object` to customise how the collection is loaded
     - `source`: (optional): `'default' | 'server' | 'cache'` Describes whether we should get from server or cache.
-  - `snapshotOptions`: (optional) `firestore.SnapshotOptions` to customise how data is retrieved from snapshots
   - `initialValue`: (optional) the initial value returned by the hook, until data from the firestore query has loaded
+  - `snapshotOptions`: (optional) `firestore.SnapshotOptions` to customise how data is retrieved from snapshots
 
 Returns:
 
@@ -247,9 +247,9 @@ The `useDocumentData` hook takes the following parameters:
 
 - `reference`: (optional) `firestore.DocumentReference` for the data you would like to load
 - `options`: (optional) `Object` with the following parameters:
+  - `initialValue`: (optional) the initial value returned by the hook, until data from the firestore query has loaded
   - `snapshotListenOptions`: (optional) `firestore.SnapshotListenOptions` to customise how the collection is loaded
   - `snapshotOptions`: (optional) `firestore.SnapshotOptions` to customise how data is retrieved from snapshots
-  - `initialValue`: (optional) the initial value returned by the hook, until data from the firestore query has loaded
 
 Returns:
 
@@ -275,8 +275,8 @@ The `useDocumentDataOnce` hook takes the following parameters:
 - `options`: (optional) `Object` with the following parameters:
   - `getOptions`: (optional) `Object` to customise how the collection is loaded
     - `source`: (optional): `'default' | 'server' | 'cache'` Describes whether we should get from server or cache
-  - `snapshotOptions`: (optional) `firestore.SnapshotOptions` to customise how data is retrieved from snapshots
   - `initialValue`: (optional) the initial value returned by the hook, until data from the firestore query has loaded
+  - `snapshotOptions`: (optional) `firestore.SnapshotOptions` to customise how data is retrieved from snapshots
 
 Returns:
 

firestore/useDocument.ts

@@ -7,6 +7,7 @@ import {
   getDocFromCache,
   getDocFromServer,
   onSnapshot,
+  SnapshotOptions,
 } from 'firebase/firestore';
 import { useEffect, useMemo } from 'react';
 import { useLoadingValue } from '../util';
@@ -120,13 +121,12 @@ export const useDocumentData = <T = DocumentData>(
   docRef?: DocumentReference<T> | null,
   options?: DataOptions<T> & InitialValueOptions<T>
 ): DocumentDataHook<T> => {
-  const snapshotOptions = options?.snapshotOptions;
   const [snapshot, loading, error] = useDocument<T>(docRef, options);
 
-  const initialValue = options?.initialValue;
-  const value = useMemo(
-    () => (snapshot?.data(snapshotOptions) ?? initialValue) as T | undefined,
-    [snapshot, snapshotOptions, initialValue]
+  const value = getValueFromSnapshot(
+    snapshot,
+    options?.snapshotOptions,
+    options?.initialValue
   );
 
   const resArray: DocumentDataHook<T> = [value, loading, error, snapshot];
@@ -137,16 +137,15 @@ export const useDocumentDataOnce = <T = DocumentData>(
   docRef?: DocumentReference<T> | null,
   options?: OnceDataOptions<T> & InitialValueOptions<T>
 ): DocumentDataOnceHook<T> => {
-  const snapshotOptions = options?.snapshotOptions;
   const [snapshot, loading, error, loadData] = useDocumentOnce<T>(
     docRef,
     options
   );
 
-  const initialValue = options?.initialValue;
-  const value = useMemo(
-    () => (snapshot?.data(snapshotOptions) ?? initialValue) as T | undefined,
-    [snapshot, snapshotOptions, initialValue]
+  const value = getValueFromSnapshot(
+    snapshot,
+    options?.snapshotOptions,
+    options?.initialValue
   );
 
   const resArray: DocumentDataOnceHook<T> = [
@@ -172,3 +171,14 @@ const getDocFnFromGetOptions = (
       return getDocFromServer;
   }
 };
+
+const getValueFromSnapshot = <T>(
+  snapshot: DocumentSnapshot<T> | undefined,
+  options?: SnapshotOptions,
+  initialValue?: T
+): T | undefined => {
+  return useMemo(
+    () => (snapshot?.data(options) ?? initialValue) as T | undefined,
+    [snapshot, options, initialValue]
+  );
+};