NewChain Contract Examples

These simple examples are for the beginner of newchain contract development. If you have any problem, let me know.

Steps for create your first project hello

Install newtruffle

npm install -g newtruffle

Initialize project

mkdir hello
cd hello
newtruffle init
echo "{\"name\":\"hello\"}" >package.json 
npm install newtruffle-hdwallet-provider

Configure the network parameter in truffle-config.js

....
const HDWalletProvider = require("newtruffle-hdwallet-provider");
...
    testnet: {
      provider: function() { 
        return new HDWalletProvider("<your mnemonic>", 'https://rpc1.newchain.newtonproject.org', "testnet") 
      },
      network_id: "1007" // newchain testnet id
    },
 ...

Replace <your mnemonic> by your mnemonic.

Create contract

Execute command

newtruffle create contract Counter

Edit the Counter.sol under contracts directory

pragma solidity ^0.5.0;


contract Counter {
  uint count;
  constructor() public {
    count = 0;
  }
  function increment() public {
    count = count + 1;
  }

  function get() public view returns (uint) {
    return count;
  }
}

Compile contract

newtruffle compile

Test contract

Create the testcase file CounterTest.js under test directory

const Counter = artifacts.require('Counter');

contract('Counter', function(accounts) {
  let counter;

  beforeEach(async function() {
    // Deploy contracts
    counter = await Counter.new();
    console.log("new contract address:" + counter.address);
  });

  it('test the get function', async function() {
    await counter.increment();
    var result = await counter.get();
    console.log("result is " + result);
  });
});

Execute command

newtruffle test --network testnet