get() server data must be indexed (#4796)

Author: jmwski

.changeset/rotten-wombats-shop.md

@@ -0,0 +1,5 @@
+---
+'@firebase/database': patch
+---
+
+Fix `index not defined` errors for orderByChild get requests

packages/database/src/core/Repo.ts

@@ -466,7 +466,9 @@ export function repoGetValue(repo: Repo, query: QueryContext): Promise<Node> {
   }
   return repo.server_.get(query).then(
     payload => {
-      const node = nodeFromJSON(payload as string);
+      const node = nodeFromJSON(payload as string).withIndex(
+        query._queryParams.getIndex()
+      );
       const events = syncTreeApplyServerOverwrite(
         repo.serverSyncTree_,
         query._path,