openzeppelin-contracts/test/utils/ReentrancyGuard.test.js

const { ethers } = require('hardhat');
const { expect } = require('chai');
const { loadFixture } = require('@nomicfoundation/hardhat-network-helpers');

async function fixture() {
  const mock = await ethers.deployContract('ReentrancyMock');
  return { mock };
}

describe('ReentrancyGuard', function () {
  beforeEach(async function () {
    Object.assign(this, await loadFixture(fixture));
  });

  it('nonReentrant function can be called', async function () {
    expect(await this.mock.counter()).to.equal(0n);
    await this.mock.callback();
    expect(await this.mock.counter()).to.equal(1n);
  });

  it('does not allow remote callback', async function () {
    const attacker = await ethers.deployContract('ReentrancyAttack');
    await expect(this.mock.countAndCall(attacker)).to.be.revertedWith('ReentrancyAttack: failed call');
  });

  it('_reentrancyGuardEntered should be true when guarded', async function () {
    await this.mock.guardedCheckEntered();
  });

  it('_reentrancyGuardEntered should be false when unguarded', async function () {
    await this.mock.unguardedCheckNotEntered();
  });

  // The following are more side-effects than intended behavior:
  // I put them here as documentation, and to monitor any changes
  // in the side-effects.
  it('does not allow local recursion', async function () {
    await expect(this.mock.countLocalRecursive(10n)).to.be.revertedWithCustomError(
      this.mock,
      'ReentrancyGuardReentrantCall',
    );
  });

  it('does not allow indirect local recursion', async function () {
    await expect(this.mock.countThisRecursive(10n)).to.be.revertedWith('ReentrancyMock: failed call');
  });
});