erc20 mixer support WIP

test/ERC20Mixer.test.js

@@ -0,0 +1,126 @@
+/* global artifacts, web3, contract */
+require('chai')
+  .use(require('bn-chai')(web3.utils.BN))
+  .use(require('chai-as-promised'))
+  .should()
+const fs = require('fs')
+
+const { toBN, toHex, randomHex } = require('web3-utils')
+const { takeSnapshot, revertSnapshot } = require('../lib/ganacheHelper')
+
+const Mixer = artifacts.require('./ERC20Mixer.sol')
+const Token = artifacts.require('./ERC20Mock.sol')
+const { AMOUNT, MERKLE_TREE_HEIGHT, EMPTY_ELEMENT } = process.env
+
+const websnarkUtils = require('websnark/src/utils')
+const buildGroth16 = require('websnark/src/groth16')
+const stringifyBigInts = require('websnark/tools/stringifybigint').stringifyBigInts
+const unstringifyBigInts2 = require('snarkjs/src/stringifybigint').unstringifyBigInts
+const snarkjs = require('snarkjs')
+const bigInt = snarkjs.bigInt
+const crypto = require('crypto')
+const circomlib = require('circomlib')
+const MerkleTree = require('../lib/MerkleTree')
+
+const rbigint = (nbytes) => snarkjs.bigInt.leBuff2int(crypto.randomBytes(nbytes))
+const pedersenHash = (data) => circomlib.babyJub.unpackPoint(circomlib.pedersenHash.hash(data))[0]
+
+function generateDeposit() {
+  let deposit = {
+    secret: rbigint(31),
+    nullifier: rbigint(31),
+  }
+  const preimage = Buffer.concat([deposit.nullifier.leInt2Buff(31), deposit.secret.leInt2Buff(31)])
+  deposit.commitment = pedersenHash(preimage)
+  return deposit
+}
+
+// eslint-disable-next-line no-unused-vars
+function BNArrayToStringArray(array) {
+  const arrayToPrint = []
+  array.forEach(item => {
+    arrayToPrint.push(item.toString())
+  })
+  return arrayToPrint
+}
+
+function getRandomReceiver() {
+  let receiver = rbigint(20)
+  while (toHex(receiver.toString()).length !== 42) {
+    receiver = rbigint(20)
+  }
+  return receiver
+}
+
+function snarkVerify(proof) {
+  proof = unstringifyBigInts2(websnarkUtils.fromSolidityInput(proof))
+  const verification_key = unstringifyBigInts2(require('../build/circuits/withdraw_verification_key.json'))
+  return snarkjs['groth'].isValid(verification_key, proof, proof.publicSignals)
+}
+
+contract('Mixer', accounts => {
+  let mixer
+  let token
+  const sender = accounts[0]
+  const operator = accounts[0]
+  const levels = MERKLE_TREE_HEIGHT || 16
+  const zeroValue = EMPTY_ELEMENT || 1337
+  const value = AMOUNT || '1000000000000000000' // 1 ether
+  let snapshotId
+  let prefix = 'test'
+  let tree
+  const fee = bigInt(AMOUNT).shr(1) || bigInt(1e17)
+  const receiver = getRandomReceiver()
+  const relayer = accounts[1]
+  let groth16
+  let circuit
+  let proving_key
+
+  before(async () => {
+    tree = new MerkleTree(
+      levels,
+      zeroValue,
+      null,
+      prefix,
+    )
+    mixer = await Mixer.deployed()
+    token = await Token.deployed()
+    token.mint(sender, value)
+    snapshotId = await takeSnapshot()
+    groth16 = await buildGroth16()
+    circuit = require('../build/circuits/withdraw.json')
+    proving_key = fs.readFileSync('build/circuits/withdraw_proving_key.bin').buffer
+  })
+
+  describe('#constructor', () => {
+    it('should initialize', async () => {
+      const tokenFromContract = await mixer.token()
+      tokenFromContract.should.be.equal(token.address)
+    })
+  })
+
+  describe('#deposit', () => {
+    it.only('should work', async () => {
+      const commitment = 43
+      await token.approve(mixer.address, value)
+
+      let { logs } = await mixer.deposit(commitment, { from: sender })
+
+      logs[0].event.should.be.equal('Deposit')
+      logs[0].args.commitment.should.be.eq.BN(toBN(commitment))
+      logs[0].args.leafIndex.should.be.eq.BN(toBN(0))
+    })
+  })
+
+  afterEach(async () => {
+    await revertSnapshot(snapshotId.result)
+    // eslint-disable-next-line require-atomic-updates
+    snapshotId = await takeSnapshot()
+    tree = new MerkleTree(
+      levels,
+      zeroValue,
+      null,
+      prefix,
+    )
+  })
+})