Add comprehensive tests for PillarStakedToken contract

[AdekunleBamz]

Summary

This PR adds comprehensive test coverage for the PillarStakedToken (stkPLR) ERC20 token contract.

File Added

• test/PillarStakedToken.spec.js - Complete test suite for PillarStakedToken

Test Coverage (20+ test cases)

Deployment Tests:

• Contract deploys with correct name and symbol
• DEFAULT_ADMIN_ROLE is set to deployer
• Initial MINTER_ROLE is granted to deployer

Minting Tests:

• MINTER_ROLE holder can mint tokens
• Non-minter cannot mint tokens
• Role granting works correctly
• Revoked minter cannot mint

Burning Tests:

• Token holder can burn their tokens
• Cannot burn more than balance

Transfer Restriction Tests:

• Non-MINTER_ROLE cannot transfer tokens
• MINTER_ROLE can transfer on behalf of users
• Cannot transfer to zero address

Role Management Tests:

• Admin can revoke MINTER_ROLE
• Role revocation prevents minting

ERC20 Standard Tests:

• Correct decimals (18)
• Total supply returns valid value
• Allowance works correctly
• TransferFrom decreases allowance

Why This Matters

PillarStakedToken is a critical component of the Pillar DAO ecosystem:

1. Staking mechanism relies on this token
2. Transfer restrictions ensure only staking contract can move tokens
3. Role-based access control for minting

Testing

Run tests with:

npx hardhat test test/PillarStakedToken.spec.js