TypeError: Cannot read property '_isHexString' of undefined

Hi,

I’m using merkletreejs for the following test:

    it("return a baseURI + tokenURI for tokenId", async () => {
      const [redeemer, usr1, usr2, usr3, usr4] = await ethers.getSigners()
      const accounts = [redeemer.address, usr1.address, usr2.address, usr3.address, usr4.address]
      const merkleTree = new MerkleTree(accounts, keccak256, {
        hashLeaves: true,
        sortPairs: true,
      })

      const root = merkleTree.getHexRoot()
      const rootHashes = [root, "0x00", "0x00", "0x00", "0x00"]
      const leaf = keccak256(redeemer.address)

      const proof = merkleTree.getHexProof(leaf)
      await makerbadges.connect(signers.deployer).setRootHashes(rootHashes)
      await makerbadges.connect(signers.deployer).createTemplate(template_name, template_description, template_image)
      await makerbadges.connect(redeemer).activateBadge(proof, templateId, tokenURI)
      const tokenId = await makerbadges.tokenOfOwnerByIndex(redeemer.address, index1)
      expect(await makerbadges.tokenURI(tokenId)).to.be.eq("https://badges.makerdao.com/token/" + tokenURI)
    })

and I get the following error:

  1) MakerBadges
       ERC721 metadata
         return a baseURI + tokenURI for tokenId:
     TypeError: Cannot read property '_isHexString' of undefined
      at /home/sencha/maker-badges/node_modules/merkletreejs/dist/MerkleTree.js:961:22
      at Array.map (<anonymous>)
      at new MerkleTree (node_modules/merkletreejs/dist/MerkleTree.js:51:29)
      at Context.<anonymous> (test/MakerBadges.ts:75:26)
      at step (test/MakerBadges.ts:34:23)
      at Object.next (test/MakerBadges.ts:15:53)
      at fulfilled (test/MakerBadges.ts:6:58)
      at runMicrotasks (<anonymous>)
      at processTicksAndRejections (node:internal/process/task_queues:94:5)

I’ve also tried migrating to @nomiclabs/hardhat-truffle5 and @typechain/truffle-v5, I’ve got the same issue.

OS: Ubuntu 20.04 Source Code: https://github.com/naszam/maker-badges/blob/xdai/test/MakerBadges.ts

Thanks!

[miguelmota]

Awesome!

[miguelmota]

Hey @naszam, can you try updating to 0.2.15 or newer. The input errors you’re were seeing should be fixed.

Then in your use the sortPairs: true option. The reason this is needed is because the solidity library is sorting them before hashing as seen here:

https://github.com/OpenZeppelin/openzeppelin-contracts/blob/243adff49ce1700e0ecb99fe522fb16cff1d1ddc/contracts/utils/cryptography/MerkleProof.sol#L27

if (computedHash <= proofElement) {
    computedHash = keccak256(abi.encodePacked(computedHash, proofElement));
} else {
    computedHash = keccak256(abi.encodePacked(proofElement, computedHash));
}

I also noticed that keccak256 was undefined so I had to import it as:

import * as keccak256 from "keccak256"

To have it import regularly you need to update a setting in tsconfig.json

{
  "compilerOptions": {
    "esModuleInterop": true
  }
}

And importing as expected worked:

import keccak256 from "keccak256"

However you can also use soliditySha3 as the hashing function to minimize dependencies.

This should definitely work now!

    it("return a baseURI + tokenURI for tokenId", async () => {
      const { soliditySha3 } = web3.utils
      const hash0 = soliditySha3(signers.redeemer.address)
      const hash1 = soliditySha3(signers.deployer.address)
      const hash2 = soliditySha3(signers.templater.address)
      const hash3 = soliditySha3(signers.random.address)
      const leaves = [hash0, hash1, hash2, hash3]
      const merkleTree = new MerkleTree(leaves, soliditySha3, {sortPairs: true})

      const root = merkleTree.getHexRoot()
      const rootHashes = [root]
      const leaf = soliditySha3(signers.redeemer.address)
      const proof = merkleTree.getHexProof(leaf)
      await makerbadges.connect(signers.deployer).setRootHashes(rootHashes)
      await makerbadges.connect(signers.deployer).createTemplate(template_name, template_description, template_image)
      await makerbadges.connect(signers.redeemer).activateBadge(proof, templateId, tokenURI)
      const tokenId = await makerbadges.tokenOfOwnerByIndex(signers.redeemer.address, index1)
      expect(await makerbadges.tokenURI(tokenId)).to.be.eq("https://badges.makerdao.com/token/" + tokenURI)
    })

Test results:

  MakerBadges
    Setup
      ✓ deployer has the default admin role (40ms)
      ✓ deployer has the templater role
      ✓ deployer has the pauser role
    ERC721 metadata
      ✓ has a name
      ✓ has a symbol
      ✓ has a baseURI
      ✓ return an updated baseURI
      ✓ reverts when querying metadata for non existent tokenId
      ✓ return a baseURI + tokenURI for tokenId (73ms)
    createTemplate()
      ✓ templater should be able to create a template
      ✓ should emit the appropriate event when a template is created
      ✓ should not allow create a new template from random user


  12 passing (3s)