From 59d35cc02bec5f18b9140b5929e8f81f3c07dc71 Mon Sep 17 00:00:00 2001
From: ross-weir <29697678+ross-weir@users.noreply.github.com>
Date: Sun, 21 Jan 2024 19:38:03 +1100
Subject: [PATCH 1/2] add batch prover digest method

---
 .../authenticated-avl-tree/src/batch_avl_prover.rs     |  7 +++++++
 .../tests/batch-avl-prover.test.ts                     | 10 ++++++++++
 2 files changed, 17 insertions(+)

diff --git a/packages/authenticated-avl-tree/src/batch_avl_prover.rs b/packages/authenticated-avl-tree/src/batch_avl_prover.rs
index 76306d5..2eec12d 100644
--- a/packages/authenticated-avl-tree/src/batch_avl_prover.rs
+++ b/packages/authenticated-avl-tree/src/batch_avl_prover.rs
@@ -1,6 +1,7 @@
 use crate::batch_node::AVLTree;
 use crate::operation::{Operation, TsOperationType};
 use derive_more::{From, Into};
+use ergo_avltree_rust::authenticated_tree_ops::AuthenticatedTreeOps;
 use ergo_avltree_rust::batch_avl_prover::BatchAVLProver as NativeBatchAVLProver;
 use ergo_lib_utils::MapJsValueErrorResult;
 use js_sys::Uint8Array;
@@ -41,4 +42,10 @@ impl BatchAVLProver {
     pub fn generate_proof(&mut self) -> Box<[u8]> {
         self.0.generate_proof().to_vec().into_boxed_slice()
     }
+
+    pub fn digest(&self) -> JsValue {
+        self.0.digest().map_or(JsValue::UNDEFINED, |digest| {
+            Uint8Array::from(digest.to_vec().as_slice()).into()
+        })
+    }
 }
diff --git a/packages/authenticated-avl-tree/tests/batch-avl-prover.test.ts b/packages/authenticated-avl-tree/tests/batch-avl-prover.test.ts
index d5678c2..c85cd17 100644
--- a/packages/authenticated-avl-tree/tests/batch-avl-prover.test.ts
+++ b/packages/authenticated-avl-tree/tests/batch-avl-prover.test.ts
@@ -13,6 +13,16 @@ function removeOp(key: string) {
 }
 
 describe("BatchAVLProver", () => {
+  it("should return the expected empty digest", () => {
+    const tree = new AVLTree(32);
+    const bv = new BatchAVLProver(tree, true);
+    const actualDigest = bytesToHex(bv.digest());
+
+    expect(actualDigest).toBe(
+      "4ec61f485b98eb87153f7c57db4f5ecd75556fddbc403b41acf8441fde8e160900"
+    );
+  });
+
   it("should produce the same proofs as the native rust library", () => {
     const insertList = [
       insertOp(

From 51fa2e921ea521b8df642c43e5384312c1ab50bc Mon Sep 17 00:00:00 2001
From: ross-weir <29697678+ross-weir@users.noreply.github.com>
Date: Sun, 21 Jan 2024 19:38:56 +1100
Subject: [PATCH 2/2] add changeset

---
 .changeset/empty-ducks-sip.md | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 .changeset/empty-ducks-sip.md

diff --git a/.changeset/empty-ducks-sip.md b/.changeset/empty-ducks-sip.md
new file mode 100644
index 0000000..7009486
--- /dev/null
+++ b/.changeset/empty-ducks-sip.md
@@ -0,0 +1,5 @@
+---
+"@ergoplatform/authenticated-avl-tree": patch
+---
+
+Add `BatchAVLProver.digest()` method