From 4630169e3d640564b0b26ff9e877f76e9f83137a Mon Sep 17 00:00:00 2001
From: Philippe Laferriere <plafer@protonmail.com>
Date: Tue, 5 Dec 2023 09:24:33 -0500
Subject: [PATCH] set_subtree: return root

---
 src/merkle/simple_smt/mod.rs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/merkle/simple_smt/mod.rs b/src/merkle/simple_smt/mod.rs
index 3b40893b..4ce94a41 100644
--- a/src/merkle/simple_smt/mod.rs
+++ b/src/merkle/simple_smt/mod.rs
@@ -245,11 +245,13 @@ impl SimpleSmt {
 
     /// Inserts a subtree at the specified index. The depth at which the subtree is inserted is
     /// computed as `self.depth() - subtree.depth()`.
+    ///
+    /// Returns the new root.
     pub fn set_subtree(
         &mut self,
         subtree_insertion_index: u64,
         subtree: SimpleSmt,
-    ) -> Result<(), MerkleError> {
+    ) -> Result<RpoDigest, MerkleError> {
         if subtree.depth() > self.depth() {
             return Err(MerkleError::InvalidSubtreeDepth {
                 subtree_depth: subtree.depth(),
@@ -298,7 +300,7 @@ impl SimpleSmt {
         // --------------
         self.recompute_nodes_from_index_to_root(subtree_root_index, subtree.root);
 
-        Ok(())
+        Ok(self.root)
     }
 
     // HELPER METHODS