utils.js

// Copied from https://github.com/gnosis/safe-contracts/blob/development/test/utils.js

const util = require('util')
const lightwallet = require('eth-lightwallet')
const { assert } = require('chai')

async function getParamFromTxEvent (transaction, eventName, paramName, contract, contractFactory, subject) {
  assert.isObject(transaction)
  if (subject != null) {
    // logGasUsage(subject, transaction)
  }
  let logs = transaction.logs
  if (eventName != null) {
    logs = logs.filter((l) => l.event === eventName && l.address === contract)
  }
  assert.equal(logs.length, 1, 'too many logs found!')
  let param = logs[0].args[paramName]
  if (contractFactory != null) {
    let contract = await contractFactory.at(param)
    assert.isObject(contract, `getting ${paramName} failed for ${param}`)
    return contract
  } else {
    return param
  }
}

function logGasUsage (subject, transactionOrReceipt) {
  let receipt = transactionOrReceipt.receipt || transactionOrReceipt
  console.log('    Gas costs for ' + subject + ': ' + receipt.gasUsed)
}

async function createLightwallet () {
  // Create lightwallet accounts
  const createVault = util.promisify(lightwallet.keystore.createVault).bind(lightwallet.keystore)
  const keystore = await createVault({
    hdPathString: "m/44'/60'/0'/0",
    seedPhrase: 'pull rent tower word science patrol economy legal yellow kit frequent fat',
    password: 'test',
    salt: 'testsalt'
  })
  const keyFromPassword = await util.promisify(keystore.keyFromPassword).bind(keystore)('test')
  keystore.generateNewAddress(keyFromPassword, 20)
  return {
    keystore: keystore,
    accounts: keystore.getAddresses(),
    passwords: keyFromPassword
  }
}

function signTransaction (lw, signers, transactionHash) {
  let signatureBytes = '0x'
  signers.sort()
  for (var i = 0; i < signers.length; i++) {
    let sig = lightwallet.signing.signMsgHash(lw.keystore, lw.passwords, transactionHash, signers[i])
    signatureBytes += sig.r.toString('hex') + sig.s.toString('hex') + sig.v.toString(16)
  }
  return signatureBytes
}

Object.assign(exports, {
  getParamFromTxEvent, // keep
  logGasUsage, // keep
  createLightwallet, // keep
  signTransaction // keep
})