Funding a MetaMask Account with Ganache

example.js

const Web3 = require('web3');
const fundMetaMaskFromDefaultAccounts = async (amountETH, providerUrl) => {
  if (window.web3) {
    const metaMaskWeb3 = window.web3;
    const ganacheWeb3 = new Web3(new Web3.providers.HttpProvider(providerUrl));
    const getAccounts = someWeb3 => {
      return new Promise((resolve, reject) => {
        someWeb3.eth.getAccounts(async (err, accounts) => {
          if (err) {
            reject(err);
          } else {
            resolve(accounts);
          }
        });
      });
    };
    const getBalance = (someWeb3, someAddress) => {
      return new Promise((resolve, reject) => {
        someWeb3.eth.getBalance(someAddress, (err, balance) => {
          if (err) {
            reject(err);
          } else {
            resolve(balance.toNumber());
          }
        });
      });
    };

    let metaMaskAccounts = await getAccounts(metaMaskWeb3);
    let metaMaskAccountBalance = await getBalance(
      metaMaskWeb3,
      metaMaskAccounts[0]
    );

    console.log('unfunded account: ', {
      metaMaskAccounts,
      metaMaskAccountBalance
    });

    let defaultAccounts = await getAccounts(ganacheWeb3);

    let receipt = await ganacheWeb3.eth.sendTransaction({
      from: defaultAccounts[0],
      to: metaMaskAccounts[0],
      value: ganacheWeb3.toWei(amountETH, 'ether'),
      gasLimit: 21000,
      gasPrice: 20000000000
    });

    console.log(receipt);

    metaMaskAccountBalance = await getBalance(
      metaMaskWeb3,
      metaMaskAccounts[0]
    );

    console.log('funded account: ', {
      metaMaskAccounts,
      metaMaskAccountBalance
    });
  } else {
    console.log('MetaMask is not available, please install it.');
  }
};