smartContractUpload.js

// ************************************************************************************************* //
//
//  In order to upload a Smart contract we have to follow a series of steps:
//
//      1. Library imports
//          a) solc: .sol file's extension compiler
//          b) fs: Node native file reader
//          c) web3: A new web3 instance that connects to Ganache's default port
//
//      2.  Smart Contract compilation 
//          a) Language: Source code language, such as "Solidity", "Vyper", etc.
//          b) Sources: File name with file's stringed content underneath
//          c) Settings: Other settings to enable metadata, abi output, etc.
//          d) CompiledContract: Stringed, compiled and parsed json file with ready output
//
//      3. Data preparation
//          a) ContractABI: Application binary interface that sets the instructions for the EVM
//          b) Bytecode: Unreadable low-level programming language interpreted by the EVM
//
//      4. Contract object and account address
//          a) DeployedContract: Contract object you feed it the ABI calls from contractABI.
//          b) Account: Ganache's account that signs the contract transaction
//      
//      5. Parameters:
//          a) Payload: Is an object that contains the bytecode created on compile
//          b) Parameter.from: Ganache's account that signs the contract transaction
//          c) Gas: The maximum gas provided for a transaction (gas limit).
//          d) GasPrice: The gas price in wei to use for transactions.
//
//      6. Deploying:
//          a) First we call deploy with the payload (aka the bytecode object)
//          b) Then we send the config parameters and wait for the creation success
//
// ************************************************************************************************* //

// 1. Library Imports
const solc = require("solc");
const fs = require("fs");
const Web3 = require("web3");
const web3 = new Web3("http://127.0.0.1:7545");

// 2. Smart Contract compilation
var input = {
    language: "Solidity",
    sources: {
        'saluten.sol' : {
            content: fs.readFileSync("./app/saluten.sol", "utf8").toString()
        }
    },
    settings: {
        outputSelection: {
            "*": {
                "*": ["*"]
            }
        }
    }
};

const CompiledContract = JSON.parse(solc.compile(JSON.stringify(input)));


// 3. Data preparation
let contractABI = CompiledContract.contracts['saluten.sol'].NumberStorage.abi
let bytecode = CompiledContract.contracts['saluten.sol'].NumberStorage.evm.bytecode.object

// 4. Contract object and account address
let deployedContract = new web3.eth.Contract(contractABI);
let account = '0xdCC9F2874f78C04dDEED66e51C83c1652A73E663'; // A Ganache application's account address

// 5. Parameters we are going to pass
let payload = {
    data: bytecode
}

let parameter = {
    from: account,
    gas: web3.utils.toHex(800000),
    gasPrice: web3.utils.toHex(web3.utils.toWei('30', 'gwei'))
}

// 6. Deploying the smart contract!
deployedContract.deploy(payload).send(parameter, (err, transactionHash) => {
    console.log('Transaction Hash :', transactionHash);
}).on('confirmation', () => {}).then((newContractInstance) => {
    console.log('Deployed Contract Address : ', newContractInstance.options.address);
})