sogoiii

var MetaCoin = artifacts.require("./MetaCoin.sol");

contract('MetaCoin', function(accounts) {

  it("should put 10000 MetaCoin in the first account", async function() {
    let meta = await MetaCoin.deployed();
    let balance = await meta.getBalance.call(accounts[0]);
    assert.equal(balance.valueOf(), 10000, "10000 wasn't in teh first account")
  });

sogoiii

pragma solidity ^0.4.8;
contract Verifier {
    function recoverAddr(bytes32 msgHash, uint8 v, bytes32 r, bytes32 s) returns (address) {
        return ecrecover(msgHash, v, r, s);
    }
    
    function isSigned(address _addr, bytes32 msgHash, uint8 v, bytes32 r, bytes32 s) returns (bool) {
        return ecrecover(msgHash, v, r, s) == _addr;
    }
}

sogoiii

const Web3 = require('web3')
const provider = new Web3.providers.HttpProvider('http://localhost:8545')
const web3 = new Web3(provider)

function toHex(str) {
 var hex = ''
 for(var i=0;i<str.length;i++) {
  hex += ''+str.charCodeAt(i).toString(16)
 }
 return hex

sogoiii

curl -X POST localhost:8545 --data '{
"jsonrpc":"2.0",
"method": "eth_sign",
"params":["0x2fb5949a6a1dc03b6d59d4723bc913230a155d0d", "0x0564b25c8fcd6766f672d43252c8ee2597ad6c7a35315cf13e3b4d00bafc2e9f"],
"id":1
}'

sogoiii

signature = signature.substr(2); //remove 0x
const r = '0x' + signature.slice(0, 64)
const s = '0x' + signature.slice(64, 128)
const v = '0x' + signature.slice(128, 130)
const v_decimal = web3.toDecimal(v)

sogoiii

//...
const SignVerifyArtifact = require('./contracts/SignAndVerifyExample')
const SignVerify = contract(SignVerifyArtifact)
SignVerify.setProvider(provider)
//...
SignVerify
  .deployed()
  .then(instance => {
    let fixed_msg = `\x19Ethereum Signed Message:\n${msg.length}${msg}`
    let fixed_msg_sha = web3.sha3(fixed_msg)

sogoiii

const status = () => {
    return MetaCoin.deployed()
          .then(instance => {
             return instance.getBalance.call(accounts[0]);
          })
          .then(balance => {
             assert.equal(balance.valueOf(), 10000, "10000 wasn't in the first account");
          })
}

sogoiii

const operationOne = function async (data) {
  let step1 = await somePromise(data)
  let step2 = await anotherPromise(step1)
  return step2.data
}
actionOne()
  .then(operationOne)
  .then(data => {
    //more work
  })

sogoiii

var MetaCoin = artifacts.require("./MetaCoin.sol");
// ... more code
contract('MetaCoin', function(accounts) {

  it("should put 10000 MetaCoin in the first account", async function() {
    let meta = await MetaCoin.deployed();
    let balance = await meta.getBalance.call(accounts[0]);
    assert.equal(balance.valueOf(), 10000, "10000 wasn't in the first account")
  });
   // ... more code

sogoiii

it("should fail because function does not exist on contract", async function () {
    let meta = await MetaCoin.deployed();
    try {
      await meta.someNonExistentFn.call();
    } catch (e) {
      return true;
    }
    throw new Error("I should never see this!")
  })