Small JS template for writing Ethereum/Solidity tests

ethereum-test-template.js

/* Use this with an overmind Procfile like this:
geth: geth --dev --rpc console
jest: pnpx jest --watchAll
*/
const ChildProcess = require('child_process')
const Web3 = require('web3')
const Assert = require('assert')

function addressOf(contract) {
  return contract.options.address
}

function compile(filename) {
  const solc = ChildProcess.spawnSync('solc', ['--combined-json=abi,bin', filename])
  if (solc.status !== 0) throw Error(solc.stderr.toString())
  return JSON.parse(solc.stdout)
}

function deploy(contractInfo, from, ...args) {
  const abi = JSON.parse(contractInfo.abi)
  return new web3.eth.Contract(abi).deploy({data: '0x' + contractInfo.bin, arguments: args}).send({from, gas: 2e6})
}

let web3 = new Web3('http://localhost:8545')

test('Wait for RPC', async () => {
  while (true) {
    try {
      return await web3.eth.getAccounts()
    }
    catch(err) {
      await new Promise(resolve => setTimeout(resolve, 100))
    }
  }
})