From 0fe4c17bc1c058ce8209db77da601e6f6a37dd0c Mon Sep 17 00:00:00 2001
From: benjrome <benjrome@gmail.com>
Date: Thu, 7 May 2020 18:58:07 +0100
Subject: [PATCH] allow use of valuechanges for collectiongroup

---
 .../collection-group/collection-group.ts      | 23 +++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/src/firestore/collection-group/collection-group.ts b/src/firestore/collection-group/collection-group.ts
index b20942d14..6193b84ae 100644
--- a/src/firestore/collection-group/collection-group.ts
+++ b/src/firestore/collection-group/collection-group.ts
@@ -81,12 +81,27 @@ export class AngularFirestoreCollectionGroup<T=DocumentData> {
 
   /**
    * Listen to all documents in the collection and its possible query as an Observable.
+   *
+   * If the `idField` option is provided, document IDs are included and mapped to the
+   * provided `idField` property name.
+   * @param options
    */
-  valueChanges(): Observable<T[]> {
-    const fromCollectionRefScheduled$ = fromCollectionRef<T>(this.query, this.afs.schedulers.outsideAngular);
-    return fromCollectionRefScheduled$
+  valueChanges(): Observable<T[]>
+  valueChanges({}): Observable<T[]>
+  valueChanges<K extends string>(options: {idField: K}): Observable<(T & { [T in K]: string })[]>
+  valueChanges<K extends string>(options: {idField?: K} = {}): Observable<T[]> {
+    return fromCollectionRef<T>(this.query, this.afs.schedulers.outsideAngular)
       .pipe(
-        map(actions => actions.payload.docs.map(a => a.data())),
+        map(actions => actions.payload.docs.map(a => {
+          if (options.idField) {
+            return {
+              ...a.data() as Object,
+              ...{ [options.idField]: a.id }
+            } as T & { [T in K]: string };
+          } else {
+            return a.data()
+          }
+        })),
         this.afs.keepUnstableUntilFirst
       );
   }