misc-snippets.js

//** create new ether account **//
const account1 = web3.eth.accounts.create();

console.log(" **1** ", account1.address, " **1** ", account1.privateKey);

//** do transaction **//
web3.eth.getTransactionCount(address1, (err, txCount) => {
  // Build the transaction
  const txObject = {
    nonce: web3.utils.toHex(txCount),
    to: address2,
    value: web3.utils.toHex(web3.utils.toWei("0.1", "ether")),
    gasLimit: web3.utils.toHex(21000),
    gasPrice: web3.utils.toHex(web3.utils.toWei("10", "gwei"))
  };

  // Sign the transaction
  const tx = new Tx(txObject);
  tx.sign(privateKey1);

  const serializedTx = tx.serialize();
  const raw = "0x" + serializedTx.toString("hex");

  // Broadcast the transaction
  web3.eth.sendSignedTransaction(raw, (err, txHash) => {
    console.log("txHash:", txHash);
    // Now go check etherscan to see the transaction!
  });
});

//** Deploy the contract **//
web3.eth.getTransactionCount(account1, (err, txCount) => {
  const data =
    "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";

  const txObject = {
    nonce: web3.utils.toHex(txCount),
    gasLimit: web3.utils.toHex(1000000), // Raise the gas limit to a much higher amount
    gasPrice: web3.utils.toHex(web3.utils.toWei("10", "gwei")),
    data: data
  };

  const tx = new Tx(txObject);
  tx.sign(privateKey1);

  const serializedTx = tx.serialize();
  const raw = "0x" + serializedTx.toString("hex");

  web3.eth.sendSignedTransaction(raw, (err, txHash) => {
    console.log("err:", err, "txHash:", txHash);
    // Use this txHash to find the contract on Etherscan!
  });
});

//** get address ether balance **//
web3.eth.getBalance(account1, (err, wei) => {
  balance = web3.utils.fromWei(wei, "ether");
  console.log("******balance 1******", balance);
});

//** contract methods **//
const contractAddress = process.env.CONTRACT_ADDRESS;
const contract = new web3.eth.Contract(abi, contractAddress);

web3.eth.getTransactionCount(account1, (err, txCount) => {
  const data = contract.methods.transfer(account2, 1000).encodeABI();

  const txObject = {
    nonce: web3.utils.toHex(txCount),
    gasLimit: web3.utils.toHex(800000), // Raise the gas limit to a much higher amount
    gasPrice: web3.utils.toHex(web3.utils.toWei("10", "gwei")),
    to: contractAddress,
    data: data
  };

  const tx = new Tx(txObject);
  tx.sign(privateKey1);

  const serializedTx = tx.serialize();
  const raw = "0x" + serializedTx.toString("hex");

  web3.eth.sendSignedTransaction(raw, (err, txHash) => {
    console.log("err:", err, "txHash:", txHash);
  });
});

// Check Token balance for account1
contract.methods.balanceOf(account1).call((err, balance) => {
  console.log({ err, balance });
});

// Check Token balance for account2
contract.methods.balanceOf(account2).call((err, balance) => {
  console.log({ err, balance });
});

contract.getPastEvents(
  "AllEvents",
  {
    fromBlock: 0,
    toBlock: "latest"
  },
  (err, events) => {
    console.log(events);
  }
);

//** get block details **//
web3.eth.getBlockNumber().then(latest => {
  for (let i = 0; i < 10; i++) {
    web3.eth.getBlock(latest - i).then(console.log);
  }
});

web3.eth.getBlock("latest").then(console.log);

// get transaction from specific block
const hash =
  "0x66b3fd79a49dafe44507763e9b6739aa0810de2c15590ac22b5e2f0a3f502073";
web3.eth.getTransactionFromBlock(hash, 2).then(console.log);

//** etc */
web3.eth.getGasPrice().then(result => {
  console.log("**** getGasPrice ****", web3.utils.fromWei(result, "ether"));
});

// Use sha256 Hashing function
console.log("web3.utils.sha3", web3.utils.sha3("Ether Playground"));

// Use keccak256 Hashing function (alias)
console.log("web3.utils.keccak256", web3.utils.keccak256("Ether Playground"));

// Get a Random Hex
console.log("web3.utils.randomHex", web3.utils.randomHex(32));