feat: integrate LazyIMT with getting the merkle proof from the chain

package.json

@@ -29,7 +29,7 @@
     "prettier:write": "prettier --write **/*.{json,md,yml} --ignore-path=.prettierignore"
   },
   "dependencies": {
-    "@zk-kit/imt.sol": "2.0.0-beta",
+    "@zk-kit/imt.sol": "https://gitpkg.now.sh/privacy-scaling-explorations/zk-kit/packages/imt.sol?0699fd1e5ad3683ae0090e0626f75d7834145500",
     "poseidon-solidity": "^0.0.5"
   }
 }

remappings.txt

@@ -1,3 +1,3 @@
 forge-std/=lib/forge-std/src/
-@zk-kit/imt.sol/=node_modules/@zk-kit/imt.sol/
+@zk-kit/imt.sol/=node_modules/@zk-kit/imt.sol/contracts
 poseidon-solidity/=node_modules/poseidon-solidity/

script/deploy.sh

@@ -80,16 +80,16 @@ if [ "$contract_name" = "rln" ]; then
     --chain $chain_name \
     $poseidon_t3_name
 
-  # Get the BinaryIMT contract address from ./broadcast/Deploy.s.sol/$chain_id/run-latest.json
-  binary_imt_name=$(cat ./broadcast/Deploy.s.sol/$chain_id/run-latest.json | jq -r '.["transactions"][1]["contractName"]')
-  binary_imt_address=$(cat ./broadcast/Deploy.s.sol/$chain_id/run-latest.json | jq -r '.["transactions"][1]["contractAddress"]') 
+  # Get the LazyIMT contract address from ./broadcast/Deploy.s.sol/$chain_id/run-latest.json
+  lazy_imt_name=$(cat ./broadcast/Deploy.s.sol/$chain_id/run-latest.json | jq -r '.["transactions"][1]["contractName"]')
+  lazy_imt_address=$(cat ./broadcast/Deploy.s.sol/$chain_id/run-latest.json | jq -r '.["transactions"][1]["contractAddress"]') 
 
-  echo "Verifying $binary_imt_name library"
-  forge verify-contract $binary_imt_address \
+  echo "Verifying $lazy_imt_name library"
+  forge verify-contract $lazy_imt_address \
   --libraries "poseidon-solidity/PoseidonT3.sol:$poseidon_t3_name:$poseidon_t3_address" \
   --watch \
   --chain $chain_name \
-  $binary_imt_name 
+  $lazy_imt_name 
 
   # Get the Verifier contract address from ./broadcast/Deploy.s.sol/$chain_id/run-latest.json
   verifier_name=$(cat ./broadcast/Deploy.s.sol/$chain_id/run-latest.json | jq -r '.["transactions"][2]["contractName"]')

src/RlnBase.sol

@@ -3,7 +3,7 @@
 pragma solidity ^0.8.19;
 
 import { IVerifier } from "./IVerifier.sol";
-import { BinaryIMT, BinaryIMTData } from "@zk-kit/imt.sol/BinaryIMT.sol";
+import { LazyIMT, LazyIMTData } from "@zk-kit/imt.sol/LazyIMT.sol";
 
 /// The tree is full
 error FullTree();
@@ -84,7 +84,7 @@ abstract contract RlnBase {
     uint32 public immutable deployedBlockNumber;
 
     /// @notice the Incremental Merkle Tree
-    BinaryIMTData public imtData;
+    LazyIMTData public imtData;
 
     /// Emitted when a new member is added to the set
     /// @param idCommitment The idCommitment of the member
@@ -107,7 +107,7 @@ abstract contract RlnBase {
         SET_SIZE = 1 << depth;
         verifier = IVerifier(_verifier);
         deployedBlockNumber = uint32(block.number);
-        BinaryIMT.initWithDefaultZeroes(imtData, 20);
+        LazyIMT.init(imtData, 20);
     }
 
     /// Allows a user to register as a member
@@ -130,7 +130,7 @@ abstract contract RlnBase {
         members[idCommitment] = idCommitmentIndex;
         indexToCommitment[idCommitmentIndex] = idCommitment;
         memberExists[idCommitment] = true;
-        BinaryIMT.insert(imtData, idCommitment);
+        LazyIMT.insert(imtData, idCommitment);
         stakedAmounts[idCommitment] = stake;
 
         emit MemberRegistered(idCommitment, idCommitmentIndex);
@@ -237,7 +237,7 @@ abstract contract RlnBase {
     }
 
     function root() external view returns (uint256) {
-        return imtData.root;
+        return LazyIMT.root(imtData, 20);
     }
 
     function getCommitments(uint256 startIndex, uint256 endIndex) public view returns (uint256[] memory) {
@@ -250,4 +250,8 @@ abstract contract RlnBase {
         }
         return commitments;
     }
+
+    function merkleProofElements(uint40 index) public view returns (uint256[] memory) {
+        return LazyIMT.merkleProofElements(imtData, index, 20);
+    }
 }