hyperlane-monorepo/solidity/core/test/interchainGasPaymaster.test.ts

import { ethers } from 'hardhat';
import { expect } from 'chai';
import { SignerWithAddress } from '@nomiclabs/hardhat-ethers/signers';

import {
  InterchainGasPaymaster,
  InterchainGasPaymaster__factory,
} from '../types';

const LEAF_INDEX = 4321;
const PAYMENT_AMOUNT = 123456789;
const OWNER = '0xdeadbeef00000000000000000000000000000000';

describe('InterchainGasPaymaster', async () => {
  let paymaster: InterchainGasPaymaster, signer: SignerWithAddress;

  before(async () => {
    [signer] = await ethers.getSigners();
  });

  beforeEach(async () => {
    const paymasterFactory = new InterchainGasPaymaster__factory(signer);
    paymaster = await paymasterFactory.deploy();
  });

  describe('#payGasFor', async () => {
    it('deposits the value into the contract', async () => {
      const paymasterBalanceBefore = await signer.provider!.getBalance(
        paymaster.address,
      );

      await paymaster.payGasFor(LEAF_INDEX, { value: PAYMENT_AMOUNT });

      const paymasterBalanceAfter = await signer.provider!.getBalance(
        paymaster.address,
      );

      expect(paymasterBalanceAfter.sub(paymasterBalanceBefore)).equals(
        PAYMENT_AMOUNT,
      );
    });

    it('emits the GasPayment event', async () => {
      await expect(paymaster.payGasFor(LEAF_INDEX, { value: PAYMENT_AMOUNT }))
        .to.emit(paymaster, 'GasPayment')
        .withArgs(LEAF_INDEX, PAYMENT_AMOUNT);
    });
  });

  describe('#claim', async () => {
    it('sends the entire balance of the contract to the owner', async () => {
      // First pay some ether into the contract
      await paymaster.payGasFor(LEAF_INDEX, { value: PAYMENT_AMOUNT });

      // Set the owner to a different address so we aren't paying gas with the same
      // address we want to observe the balance of
      await paymaster.transferOwnership(OWNER);

      const ownerBalanceBefore = await signer.provider!.getBalance(OWNER);
      expect(ownerBalanceBefore).equals(0);
      const paymasterBalanceBefore = await signer.provider!.getBalance(
        paymaster.address,
      );
      expect(paymasterBalanceBefore).equals(PAYMENT_AMOUNT);

      await paymaster.claim();

      const ownerBalanceAfter = await signer.provider!.getBalance(OWNER);
      expect(ownerBalanceAfter).equals(PAYMENT_AMOUNT);
      const paymasterBalanceAfter = await signer.provider!.getBalance(
        paymaster.address,
      );
      expect(paymasterBalanceAfter).equals(0);
    });
  });
});