From 18b8ed9fe2fc089af9ff8ac67a05b096fe7cc470 Mon Sep 17 00:00:00 2001
From: cedoor <me@cedoor.dev>
Date: Wed, 20 Mar 2024 10:52:01 +0000
Subject: [PATCH] fix(imt.sol): remove merkle proof length check

Updating LeanIMT of size 1 (tree with 1 leaf inserted), the update function should not revert.

re #210
---
 .../imt.sol/contracts/internal/InternalLeanIMT.sol     |  2 --
 packages/imt.sol/test/LeanIMT.ts                       | 10 ++++++----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/packages/imt.sol/contracts/internal/InternalLeanIMT.sol b/packages/imt.sol/contracts/internal/InternalLeanIMT.sol
index 572dbde29..d665f9b27 100644
--- a/packages/imt.sol/contracts/internal/InternalLeanIMT.sol
+++ b/packages/imt.sol/contracts/internal/InternalLeanIMT.sol
@@ -218,8 +218,6 @@ library InternalLeanIMT {
             revert LeafDoesNotExist();
         } else if (newLeaf != 0 && _has(self, newLeaf)) {
             revert LeafAlreadyExists();
-        } else if (siblingNodes.length == 0) {
-            revert WrongSiblingNodes();
         }
 
         uint256 index = _indexOf(self, oldLeaf);
diff --git a/packages/imt.sol/test/LeanIMT.ts b/packages/imt.sol/test/LeanIMT.ts
index 507e49feb..24c0e65c7 100644
--- a/packages/imt.sol/test/LeanIMT.ts
+++ b/packages/imt.sol/test/LeanIMT.ts
@@ -137,7 +137,7 @@ describe("LeanIMT", () => {
             await expect(transaction).to.be.revertedWithCustomError(leanIMT, "LeafGreaterThanSnarkScalarField")
         })
 
-        it("Should not update a leaf if there are no sibling nodes", async () => {
+        it("Should update a leaf if that's the only leaf in the tree", async () => {
             await leanIMTTest.insert(1)
 
             jsLeanIMT.insert(BigInt(1))
@@ -145,12 +145,14 @@ describe("LeanIMT", () => {
 
             const { siblings } = jsLeanIMT.generateProof(0)
 
-            const transaction = leanIMTTest.update(1, 2, siblings)
+            await leanIMTTest.update(1, 2, siblings)
 
-            await expect(transaction).to.be.revertedWithCustomError(leanIMT, "WrongSiblingNodes")
+            const root = await leanIMTTest.root()
+
+            expect(root).to.equal(jsLeanIMT.root)
         })
 
-        it("Should update a leaf", async () => {
+        it("Should update a leaf if there's more than 1 leaf in the tree", async () => {
             await leanIMTTest.insert(1)
             await leanIMTTest.insert(2)