dgf-prototype/ethereum/test/Lock.js

const {
  time,
  loadFixture,
} = require('@nomicfoundation/hardhat-toolbox/network-helpers');
const { anyValue } = require('@nomicfoundation/hardhat-chai-matchers/withArgs');
const { expect } = require('chai');
const { ethers } = require('hardhat');

describe('Lock', () => {
  // We define a fixture to reuse the same setup in every test.
  // We use loadFixture to run this setup once, snapshot that state,
  // and reset Hardhat Network to that snapshot in every test.
  async function deployOneYearLockFixture() {
    const ONE_YEAR_IN_SECS = 365 * 24 * 60 * 60;
    const ONE_GWEI = 1_000_000_000;

    const lockedAmount = ONE_GWEI;
    const unlockTime = (await time.latest()) + ONE_YEAR_IN_SECS;

    // Contracts are deployed using the first signer/account by default
    const [owner, otherAccount] = await ethers.getSigners();

    const Lock = await ethers.getContractFactory('Lock');
    const lock = await Lock.deploy(unlockTime, { value: lockedAmount });

    return {
      lock, unlockTime, lockedAmount, owner, otherAccount,
    };
  }

  describe('Deployment', () => {
    it('Should set the right unlockTime', async () => {
      const { lock, unlockTime } = await loadFixture(deployOneYearLockFixture);

      expect(await lock.unlockTime()).to.equal(unlockTime);
    });

    it('Should set the right owner', async () => {
      const { lock, owner } = await loadFixture(deployOneYearLockFixture);

      expect(await lock.owner()).to.equal(owner.address);
    });

    it('Should receive and store the funds to lock', async () => {
      const { lock, lockedAmount } = await loadFixture(
        deployOneYearLockFixture,
      );

      expect(await ethers.provider.getBalance(lock.target)).to.equal(
        lockedAmount,
      );
    });

    it('Should fail if the unlockTime is not in the future', async () => {
      // We don't use the fixture here because we want a different deployment
      const latestTime = await time.latest();
      const Lock = await ethers.getContractFactory('Lock');
      await expect(Lock.deploy(latestTime, { value: 1 })).to.be.revertedWith(
        'Unlock time should be in the future',
      );
    });
  });

  describe('Withdrawals', () => {
    describe('Validations', () => {
      it('Should revert with the right error if called too soon', async () => {
        const { lock } = await loadFixture(deployOneYearLockFixture);

        await expect(lock.withdraw()).to.be.revertedWith(
          "You can't withdraw yet",
        );
      });

      it('Should revert with the right error if called from another account', async () => {
        const { lock, unlockTime, otherAccount } = await loadFixture(
          deployOneYearLockFixture,
        );

        // We can increase the time in Hardhat Network
        await time.increaseTo(unlockTime);

        // We use lock.connect() to send a transaction from another account
        await expect(lock.connect(otherAccount).withdraw()).to.be.revertedWith(
          "You aren't the owner",
        );
      });

      it("Shouldn't fail if the unlockTime has arrived and the owner calls it", async () => {
        const { lock, unlockTime } = await loadFixture(
          deployOneYearLockFixture,
        );

        // Transactions are sent using the first signer by default
        await time.increaseTo(unlockTime);

        await expect(lock.withdraw()).not.to.be.reverted;
      });
    });

    describe('Events', () => {
      it('Should emit an event on withdrawals', async () => {
        const { lock, unlockTime, lockedAmount } = await loadFixture(
          deployOneYearLockFixture,
        );

        await time.increaseTo(unlockTime);

        await expect(lock.withdraw())
          .to.emit(lock, 'Withdrawal')
          .withArgs(lockedAmount, anyValue); // We accept any value as `when` arg
      });
    });

    describe('Transfers', () => {
      it('Should transfer the funds to the owner', async () => {
        const {
          lock, unlockTime, lockedAmount, owner,
        } = await loadFixture(
          deployOneYearLockFixture,
        );

        await time.increaseTo(unlockTime);

        await expect(lock.withdraw()).to.changeEtherBalances(
          [owner, lock],
          [lockedAmount, -lockedAmount],
        );
      });
    });
  });
});