[Request] Simple deploy/call contract example

[SilentCicero]

Could we provide a simple example of deploying and calling a simple method with ethereumjs-vm?

I would prefer if I don't need to setup accounts/balances/nonces/txs etc..

pragma solidity ^0.4.4;

contract SimpleGet { uint256 public val = 4555; }

I just want to deploy a simple contract ^^, then call the val() public constant method.

Any thoughts on this (can i use runCode/runCall/runTx.. what is recommended) @axic @wanderer ?

---

SimpleGet Contract Bytecode:

0x60606040526101c76000553415601157fe5b5b608f806100206000396000f30060606040526000357c0100000000000000000000000000000000000000000000000000000000900463ffffffff1680633c6bb43614603a575bfe5b3415604157fe5b6047605d565b6040518082815260200191505060405180910390f35b600054815600a165627a7a7230582020e95b37b367992e3e2cedd2faa7d85b517bab7f4a0108a81ade0eafe1ac62930029

val Method Call Code:

0x3c6bb436

[SilentCicero]

[update]

Here is what I came up with:

API:

interface:
runMethod({ bytecode: '0x..', interface: [ ..] } , 'someMethod', [ param1, param2 ] );

Usage:

runMethod({
  bytecode: '0x60606040526101c76000553415601157fe5b5b608f806100206000396000f30060606040526000357c0100000000000000000000000000000000000000000000000000000000900463ffffffff1680633c6bb43614603a575bfe5b3415604157fe5b6047605d565b6040518082815260200191505060405180910390f35b600054815600a165627a7a7230582020e95b37b367992e3e2cedd2faa7d85b517bab7f4a0108a81ade0eafe1ac62930029',
  interface: [{"constant":true,"inputs":[],"name":"val","outputs":[{"name":"","type":"uint256"}],"payable":false,"type":"function"}],
}, 'val', []).then(console.log).catch(console.log);

Code:

const VM = require('ethereumjs-vm');
const Tx = require('ethereumjs-tx');
const sign = require('ethjs-signer').sign;
const BN = require('ethjs').BN;
const abi = require('ethjs-abi');
const util = require('ethjs-util');

function runMethod(contract, methodName, inputs) {
  return new Promise((resolve, reject) => {
    const vm = new VM({
      enableHomestead: true,
      activatePrecompiles: true
    });

    const contractInterface = typeof contract.interface === 'string' ? JSON.parse(contract.interface) : contract.interface;
    const methodObject = contractInterface.filter(item => item.name === methodName ? 1 : 0)[0];

    const address = '0x0F6af8F8D7AAD198a7607C96fb74Ffa02C5eD86B';
    const privateKey = '0xecbcd9838f7f2afa6e809df8d7cdae69aa5dfc14d563ee98e97effd3f6a652f2';
    const genesisData = { "0F6af8F8D7AAD198a7607C96fb74Ffa02C5eD86B": "1606938044258990275541962092341162602522202993782792835301376" };

    vm.stateManager.generateGenesis(genesisData, function(){
      try {
        const tx = new Tx(sign({
            from: address,
            value: 0,
            gas: new BN('99999999999'),
            gasPrice: new BN('1'),
            nonce: new BN(0),
            data: contract.bytecode,
          }, privateKey));

        vm.runTx({ tx, skipBalance: true, skipNonce: true }, (contractError, contractTx) => {

          if (contractError) { reject(contractError); return; }

          try {
            const tx2 = new Tx(sign({
                to: `0x${contractTx.createdAddress.toString('hex')}`,
                value: 0,
                gas: new BN('9999999999'),
                gasPrice: new BN('1'),
                nonce: new BN(1),
                data: abi.encodeMethod(methodObject, inputs),
              }, privateKey));

            vm.runTx({ tx: tx2, skipBalance: true, skipNonce: true }, (callError, callTx) => {

              if (callError) { reject(callError); return; }

              try {
                const outputBytecode = `0x${callTx.vm.return.toString('hex')}`;

                const result = abi.decodeMethod(methodObject, outputBytecode);

                resolve(result);
              } catch (bytecodeError) { reject(bytecodeError); return; }
            });
          } catch (error) { reject(error); return; }
        });
      } catch (error) { reject(error); return; }
    });
  });
};

[holgerd77]

Covered by https://github.com/ethereumjs/ethereumjs-vm/tree/master/examples/run-solidity-contract, see also #277, will close.