How return variable from simple smart contract

Question

Hello I'm trying to make my first and simple test for get a variable from my first contract:

Truffle version: Truffle v4.1.14 Node: 8.12.0

pragma solidity ^0.4.4;

contract SimpleContract {
  bytes32  hello = "hello";
  function getHello() public view returns (bytes32){
    return hello;
  }
}

And I did a simple test like:

pragma solidity ^0.4.4;

import "truffle/Assert.sol";
import "truffle/DeployedAddresses.sol";

import "../contracts/SimpleContract.sol";


contract TestSimpleContract {

  function testGetHello() public {
    SimpleContract w = SimpleContract(DeployedAddresses.SimpleContract());
    bytes32  expected = "hello";
    bytes32  hello = w.getHello();

    Assert.equal(hello,expected, "SHould hello!");
  }
}

And I have a Migrations:

var Simple = artifacts.require("SimpleContract");


module.exports = function(deployer) {
  deployer.deploy(Simple);
};

And I have this truffle config

module.exports = {
   networks: {
     development: {
      host: "localhost",
      port: 7545,
      network_id: "5777"
    }
   }
 };

But I can't understand and how figure out why it return this error:

1) TestSimpleContract testGetHello: Error: VM Exception while processing transaction: revert at Object.InvalidResponse (C:\Users\Lorenzo\AppData\Roaming\npm\node_modules\truffle\build\webpack:\~\web3\lib\web3\errors.js:38:1) at C:\Users\Lorenzo\AppData\Roaming\npm\node_modules\truffle\build\webpack:\~\web3\lib\web3\requestmanager.js:86:1 at C:\Users\Lorenzo\AppData\Roaming\npm\node_modules\truffle\build\webpack:\packages\truffle-provider\wrapper.js:134:1 at XMLHttpRequest.request.onreadystatechange (C:\Users\Lorenzo\AppData\Roaming\npm\node_modules\truffle\build\webpack:\~\web3\lib\web3\httpprovider.js:128:1) at XMLHttpRequestEventTarget.dispatchEvent (C:\Users\Lorenzo\AppData\Roaming\npm\node_modules\truffle\build\webpack:\~\xhr2\lib\xhr2.js:64:1) at XMLHttpRequest._setReadyState (C:\Users\Lorenzo\AppData\Roaming\npm\node_modules\truffle\build\webpack:\~\xhr2\lib\xhr2.js:354:1) at XMLHttpRequest._onHttpResponseEnd (C:\Users\Lorenzo\AppData\Roaming\npm\node_modules\truffle\build\webpack:\~\xhr2\lib\xhr2.js:509:1) at IncomingMessage. (C:\Users\Lorenzo\AppData\Roaming\npm\node_modules\truffle\build\webpack:\~\xhr2\lib\xhr2.js:469:1) at endReadableNT (_stream_readable.js:1064:12) at _combinedTickCallback (internal/process/next_tick.js:139:11) at process._tickCallback (internal/process/next_tick.js:181:9)

Answer 1

The issue happend with ganache-cli. In order to fix it you need to run ganache-cli with networkId

> ganache-cli -i 5777