TLaaS (LEX) — Unit Test Suite with Hardhat: Writing Thorough Test Coverage

1. Purpose

A robust unit test suite ensures that TLaaS (LEX) smart contracts perform as intended across all license lifecycle operations. Hardhat provides a modern Ethereum development environment for compiling, testing, and deploying contracts with detailed debugging capabilities.

2. Testing Objectives

• Validate core license issuance, renewal, transfer, and revocation.
• Verify royalty routing accuracy.
• Confirm correct role-based access control (RBAC) behavior.
• Test dispute escalation triggers and DAO voting integration.
• Ensure compatibility with TLAAS (DLA) validation and DAL arbitration modules.

3. Recommended Test Coverage Areas

1. License Creation — Validate that only issuers can mint licenses.
2. License Renewal — Ensure renewal updates expiry and emits events.
3. Transfer & Sublicensing — Confirm proper ownership changes.
4. Royalty Distribution — Match payouts to configured percentages.
5. Override Router Integration — Test dispute routing logic.
6. Biometric/KYC Binding — Verify fingerprint or KYC hashes are stored and validated.
7. Slashing Conditions — Ensure penalties apply for validator violations.

4. Hardhat Setup

Install Dependencies:

npm install --save-dev hardhat @nomicfoundation/hardhat-toolbox @openzeppelin/contracts ethers chai mocha

Project Initialization:

npx hardhat init

5. Example Test Snippet

const { expect } = require("chai");

describe("LicenseRegistry", function () {
  let LicenseRegistry, registry, owner, issuer, holder;

  beforeEach(async function () {
    [owner, issuer, holder] = await ethers.getSigners();
    LicenseRegistry = await ethers.getContractFactory("LicenseRegistry");
    registry = await LicenseRegistry.deploy();
    await registry.deployed();
  });

  it("should allow an issuer to create a license", async function () {
    await registry.grantRole(await registry.ISSUER_ROLE(), issuer.address);
    await expect(registry.connect(issuer).issueLicense(holder.address, 1, Date.now() + 10000, "hash"))
      .to.emit(registry, "LicenseIssued")
      .withArgs(1, issuer.address, holder.address, anyValue);
  });
});

6. Testing Best Practices

• Use beforeEach hooks to deploy fresh contracts per test.
• Mock external contract calls for TLAAS and DAL interactions.
• Include negative tests to ensure unauthorized actions fail.
• Run coverage reports with
• Automate tests in CI/CD pipeline.

7. Interoperability Testing

• Simulate license validations from TLAAS.
• Trigger dispute workflows to DAL.
• Test cross-contract calls for royalty routing.

8. Benefits

• Reduces risk of production exploits.
• Ensures consistent contract behavior across updates.
• Facilitates rapid troubleshooting.
• Builds trust with ecosystem participants.

Next Article: Deployment Scripts (Testnet & Mainnet) — Environment Management