Ethereum Sandbox Client

The module is a client for Ethereum Sandbox.

Installation

$ npm install ethereum-sandbox-client

Example

var Sandbox = require('ethereum-sandbox-client');
var sandbox = new Sandbox('http://localhost:8555');

sandbox.start(function(err) {
  if (err) return console.error(err);
  console.log('sandbox started: ' + sandbox.id);
  console.log(sandbox.web3.coinbase);
  sandbox.stop(function(err) {
    if (err) console.error(err);
    else console.log('sandbox stopped');
  });
});

Mocha-test with the client:

var fs = require('fs');
var assert = require('assert');
var solc = require('solc');
var Sandbox = require('ethereum-sandbox-client');

describe('Contract', function() {
  this.timeout(60000);
  
  var sandbox = new Sandbox('http://localhost:8555');
  var compiled = compile('contracts', ['contract.sol']);
  var contract;
  
  before(function(done) {
    sandbox.start(function(err) {
      if (err) return done(err);
  
      contract = sandbox.web3.eth.contract(JSON.parse(compiled.contracts['Contract'].interface)).new({
        data: '0x' + compiled.contracts['Contract'].bytecode
      }, function(err, created) {
        if (err) return done(err);
        if (created.address) done();
      });
    });
  });
  
  it('prints string', function (done) {
    var str = "hello, ethereum!";
    
    console.log('in the test');
    
    var filter = sandbox.web3.eth.filter({
      address: contract.address
    });
    filter.watch(function(err, val) {
      if (err) return finish(err);
      assert.equal(toString(val.data), str);
      finish();
    });
    
    contract.test(str, function(err) {
      if (err) finish(err);
    });
    
    function finish(err) {
      filter.stopWatching();
      done(err);
    }
  });
  
  after(function(done) {
    sandbox.stop(function(err) {
      done(err);
    });
  });
});

function toString(hex) {
  return String.fromCharCode.apply(
    null,
    toArray(removeTrailingZeroes(hex.substr(2)))
  );
}

function removeTrailingZeroes(str) {
  if (str.length % 2 !== 0)
    console.error('Wrong hex str: ' + str);
  
  var lastNonZeroByte = 0;
  for (var i = str.length - 2; i >= 2; i -= 2) {
    if (str.charAt(i) !== '0' || str.charAt(i + 1) !== '0') {
      lastNonZeroByte = i;
      break;
    }
  }
  
  return str.substr(0, lastNonZeroByte + 2);
}

function toArray(str) {
  if (str.length % 2 !== 0)
    console.error('Wrong hex str: ' + str);
  
  var arr = [];
  for (var i = 0; i < str.length; i += 2) {
    var code = parseInt(str.charAt(i) + str.charAt(i + 1), 16);
    // Ignore non-printable characters
    if (code > 9) arr.push(code);
  }
  
  return arr;
}

function compile(dir, files) {
  var input = {};
  files.forEach(function(file) {
    input[file] = fs.readFileSync(dir + '/' + file).toString();
  });
  return solc.compile({ sources: input }, 1, function findImports(path) {
    try {
      return { contents: fs.readFileSync(dir + '/' + path).toString() };
    } catch (e) {
      return { error: e };
    }
  });
}

Also, there're tests for the DAO.

API

new Sandbox(url)

Create a new object which is able to run a sandbox on Sandbox Container with the specified URL.

sandbox.start([config,] cb)

Start a new sandbox in Sandbox Container. The client checks if there is a running Sandbox Container on the specified in the constructor URL. If not and if the URL points to localhost it runs Sandbox Container.

If config is specified, it is used as a config for the new sandbox. Otherwise the client uses ethereum.json in the project directory.

cb is a callback function (function(err) {) which is called when sendbox has been started.

sandbox.stop(cb)

Stop the started sandbox.

cb is a callback function (function(err) {) which is called when sandbox has been stopped.

sandbox.web3

Web3 object which is connected to the started sandbox.