Fix normalizeMerkleBranch

Author: ensi321

packages/light-client/src/utils/normalizeMerkleBranch.ts

@@ -9,8 +9,7 @@ export const SYNC_COMMITTEES_INDEX = 11;
  * unmodified ``branch``
  */
 export function normalizeMerkleBranch(branch: Uint8Array[], depth: number): Uint8Array[] {
-  const numBytes = Math.floor(branch.length / 8);
-  const numExtraBytesRequired = depth - numBytes;
+  const numExtraDepth = depth - branch.length;
 
-  return [...Array.from({length: numExtraBytesRequired}, () => ZERO_HASH), ...branch];
+  return [...Array.from({length: numExtraDepth}, () => ZERO_HASH), ...branch];
 }

packages/light-client/test/unit/utils.test.ts

@@ -1,6 +1,8 @@
 import {describe, it, expect} from "vitest";
 import {isValidMerkleBranch} from "../../src/utils/verifyMerkleBranch.js";
 import {computeMerkleBranch} from "../utils/utils.js";
+import {normalizeMerkleBranch} from "../../src/utils/normalizeMerkleBranch.js";
+import {ZERO_HASH} from "../../src/spec/utils.js";
 
 describe("utils", () => {
   it("constructMerkleBranch", () => {
@@ -11,4 +13,18 @@ describe("utils", () => {
 
     expect(isValidMerkleBranch(leaf, proof, depth, index, root)).toBe(true);
   });
+  it("normalizeMerkleBranch", () => {
+    const branch: Uint8Array[] = [];
+    const branchDepth = 5;
+    const newDepth = 7;
+
+    for (let i = 0; i < branchDepth; i++) {
+      branch.push(new Uint8Array(Array.from({length: 32}, () => i)));
+    }
+
+    const normalizedBranch = normalizeMerkleBranch(branch, newDepth);
+    const expectedNormalizedBranch = [ZERO_HASH, ZERO_HASH, ...branch];
+
+    expect(normalizedBranch).toEqual(expectedNormalizedBranch);
+  });
 });