BT-354 Minimum transfer by country module

contracts/compliance/modular/modules/MinTransferByCountryModule.sol

@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity 0.8.27;
+
+import "../IModularCompliance.sol";
+import "../../../token/IToken.sol";
+import "./AbstractModuleUpgradeable.sol";
+
+ event MinimumTransferAmountSet(address indexed compliance, uint16 indexed country, uint256 amount);
+
+
+/**
+ * @title MinTransferByCountry Module
+ * @dev Enforces minimum transfer amounts for token holders from specified countries
+ * when creating new investors for that country
+ */
+contract MinTransferByCountryModule is AbstractModuleUpgradeable {
+
+    mapping(address compliance => mapping(uint16 country => uint256 minAmount)) private _minimumTransferAmounts;
+
+    function initialize() external initializer {
+        __AbstractModule_init();
+    }
+
+    /**
+     * @dev Sets minimum transfer amount for a country
+     * @param country Country code
+     * @param amount Minimum transfer amount
+     */
+    function setMinimumTransferAmount(uint16 country, uint256 amount) external onlyComplianceCall {
+        _minimumTransferAmounts[msg.sender][country] = amount;
+
+        emit MinimumTransferAmountSet(msg.sender, country, amount);
+    }
+
+    /// @inheritdoc IModule
+    // solhint-disable-next-line no-empty-blocks
+    function moduleTransferAction(address _from, address _to, uint256 _value) external {}
+
+    /// @inheritdoc IModule
+    // solhint-disable-next-line no-empty-blocks
+    function moduleMintAction(address _to, uint256 _value) external {}
+
+    /// @inheritdoc IModule
+    // solhint-disable-next-line no-empty-blocks
+    function moduleBurnAction(address _from, uint256 _value) external {}
+
+    /// @inheritdoc IModule
+    function moduleCheck(
+        address _from, 
+        address _to, 
+        uint256 _amount, 
+        address _compliance
+    ) external view override returns (bool) {
+        uint16 recipientCountry = _getCountry(_compliance, _to);
+        if (_minimumTransferAmounts[_compliance][recipientCountry] == 0) {
+            return true;
+        }
+
+        // Check for internal transfer in same country
+        address idFrom = _getIdentity(_compliance, _from);
+        address idTo = _getIdentity(_compliance, _to);
+        if (idFrom == idTo) {
+            uint16 senderCountry = _getCountry(_compliance, _from);
+            return senderCountry == recipientCountry 
+                || _amount >= _minimumTransferAmounts[_compliance][recipientCountry];
+        }
+
+        IToken token = IToken(IModularCompliance(_compliance).getTokenBound());
+        // Check for new user
+        return token.balanceOf(_to) > 0
+            || _amount >= _minimumTransferAmounts[_compliance][recipientCountry];
+    }
+
+    /// @inheritdoc IModule
+    function canComplianceBind(address /*_compliance*/) external pure override returns (bool) {
+        return true;
+    }
+
+    /// @inheritdoc IModule
+    function isPlugAndPlay() external pure override returns (bool) {
+        return true;
+    }
+
+    /**
+     * @dev Module name
+     */
+    function name() public pure returns (string memory) {
+        return "MinTransferByCountryModule";
+    }
+
+
+    /// @dev function used to get the country of a wallet address.
+    /// @param _compliance the compliance contract address for which the country verification is required
+    /// @param _userAddress the address of the wallet to be checked
+    /// @return the ISO 3166-1 standard country code of the wallet owner
+    function _getCountry(address _compliance, address _userAddress) internal view returns (uint16) {
+        return IToken(IModularCompliance(_compliance).getTokenBound()).identityRegistry().investorCountry(_userAddress);
+    }
+
+    /// @dev Returns the ONCHAINID (Identity) of the _userAddress
+    /// @param _compliance the compliance contract address for which the country verification is required
+    /// @param _userAddress Address of the wallet
+    /// @return the ONCHAINID (Identity) of the _userAddress
+    function _getIdentity(address _compliance, address _userAddress) internal view returns (address) {
+        return address(IToken(IModularCompliance(_compliance).getTokenBound()).identityRegistry().identity
+            (_userAddress));
+    }
+}

index.d.ts

@@ -73,6 +73,7 @@ export namespace contracts {
   export const TransferRestrictModule: ContractJSON;
   export const TokenListingRestrictionsModule: ContractJSON;
   export const InvestorCountryCapModule: ContractJSON;
+  export const MinTransferByCountrytModule: ContractJSON;
 }
 
 export namespace interfaces {

index.js

@@ -75,6 +75,7 @@ const TransferFeesModule = require('./artifacts/contracts/compliance/modular/mod
 const TransferRestrictModule = require('./artifacts/contracts/compliance/modular/modules/TransferRestrictModule.sol/TransferRestrictModule.json');
 const TokenListingRestrictionsModule = require('./artifacts/contracts/compliance/modular/modules/TokenListingRestrictionsModule.sol/TokenListingRestrictionsModule.json');
 const InvestorCountryCapModule = require('./artifacts/contracts/compliance/modular/modules/InvestorCountryCapModule.sol/InvestorCountryCapModule.json');
+const MinTransferByCountrytModule = require('./artifacts/contracts/compliance/modular/modules/MinTransferByCountrytModule.sol/MinTransferByCountrytModule.json');
 
 module.exports = {
   contracts: {
@@ -141,6 +142,7 @@ module.exports = {
     TransferRestrictModule,
     TokenListingRestrictionsModule,
     InvestorCountryCapModule,
+    MinTransferByCountrytModule,
   },
   interfaces: {
     IToken,

test/compliances/module-min-transfer-by-country.ts

@@ -0,0 +1,186 @@
+import { loadFixture } from '@nomicfoundation/hardhat-network-helpers';
+import { SignerWithAddress } from '@nomicfoundation/hardhat-ethers/signers';
+import { ethers } from 'hardhat';
+import { expect } from 'chai';
+import { deploySuiteWithModularCompliancesFixture } from '../fixtures/deploy-full-suite.fixture';
+import { MinTransferByCountryModule, ModularCompliance } from '../../index.js';
+
+describe('MinTransferByCountryModule', () => {
+  // Test fixture
+  async function deployMinTransferByCountryModuleFullSuite() {
+    const context = await loadFixture(deploySuiteWithModularCompliancesFixture);
+
+    const module = await ethers.deployContract('MinTransferByCountryModule');
+    const proxy = await ethers.deployContract('ModuleProxy', [module.target, module.interface.encodeFunctionData('initialize')]);
+    const complianceModule = await ethers.getContractAt('MinTransferByCountryModule', proxy.target);
+
+    await context.suite.compliance.bindToken(context.suite.token.target);
+    await context.suite.compliance.addModule(complianceModule.target);
+
+    return {
+      ...context,
+      suite: {
+        ...context.suite,
+        complianceModule,
+      },
+    };
+  }
+
+  async function setMinimumTransferAmount(
+    compliance: ModularCompliance,
+    complianceModule: MinTransferByCountryModule,
+    deployer: SignerWithAddress,
+    countryCode: bigint,
+    minAmount: bigint,
+  ) {
+    return compliance
+      .connect(deployer)
+      .callModuleFunction(
+        new ethers.Interface(['function setMinimumTransferAmount(uint16 country, uint256 amount)']).encodeFunctionData('setMinimumTransferAmount', [
+          countryCode,
+          minAmount,
+        ]),
+        complianceModule.target,
+      );
+  }
+
+  describe('Initialization', () => {
+    it('should initialize correctly', async () => {
+      const {
+        suite: { compliance, complianceModule },
+      } = await loadFixture(deployMinTransferByCountryModuleFullSuite);
+
+      expect(await complianceModule.name()).to.equal('MinTransferByCountryModule');
+      expect(await complianceModule.isPlugAndPlay()).to.be.true;
+      expect(await complianceModule.canComplianceBind(compliance.target)).to.be.true;
+    });
+  });
+
+  describe('Basic operations', () => {
+    it('Should mint/burn/transfer tokens if no minimum transfer amount is set', async () => {
+      const {
+        suite: { token },
+        accounts: { tokenAgent, aliceWallet, bobWallet },
+      } = await loadFixture(deployMinTransferByCountryModuleFullSuite);
+
+      await token.connect(tokenAgent).mint(aliceWallet.address, 10);
+      await token.connect(aliceWallet).transfer(bobWallet.address, 10);
+      await token.connect(tokenAgent).burn(bobWallet.address, 10);
+    });
+  });
+
+  describe('Country Settings', () => {
+    it('should set minimum transfer amount for a country', async () => {
+      const {
+        suite: { compliance, complianceModule },
+        accounts: { deployer },
+      } = await loadFixture(deployMinTransferByCountryModuleFullSuite);
+
+      const countryCode = 42n;
+      const minAmount = ethers.parseEther('100');
+      const tx = await setMinimumTransferAmount(compliance, complianceModule, deployer, countryCode, minAmount);
+      await expect(tx).to.emit(complianceModule, 'MinimumTransferAmountSet').withArgs(compliance.target, countryCode, minAmount);
+    });
+
+    it('should revert when other than compliance tries to set minimum transfer amount', async () => {
+      const {
+        suite: { complianceModule },
+        accounts: { aliceWallet },
+      } = await loadFixture(deployMinTransferByCountryModuleFullSuite);
+
+      const countryCode = 1;
+      const minAmount = ethers.parseEther('100');
+
+      await expect(complianceModule.connect(aliceWallet).setMinimumTransferAmount(countryCode, minAmount)).to.be.revertedWithCustomError(
+        complianceModule,
+        'OnlyBoundComplianceCanCall',
+      );
+    });
+  });
+
+  describe('Transfer Validation', () => {
+    it('should allow transfer when amount meets minimum requirement', async () => {
+      const {
+        suite: { compliance, complianceModule, identityRegistry },
+        accounts: { deployer, aliceWallet, bobWallet },
+      } = await loadFixture(deployMinTransferByCountryModuleFullSuite);
+
+      const countryCode = await identityRegistry.investorCountry(aliceWallet.address);
+      const minAmount = ethers.parseEther('100');
+      await setMinimumTransferAmount(compliance, complianceModule, deployer, countryCode, minAmount);
+
+      const transferAmount = ethers.parseEther('150');
+      expect(await complianceModule.moduleCheck(bobWallet.address, aliceWallet.address, transferAmount, compliance.target)).to.be.true;
+    });
+
+    it('should prevent transfer when amount is below minimum requirement', async () => {
+      const {
+        suite: { compliance, complianceModule, identityRegistry },
+        accounts: { deployer, charlieWallet, bobWallet },
+      } = await loadFixture(deployMinTransferByCountryModuleFullSuite);
+
+      const countryCode = await identityRegistry.investorCountry(charlieWallet.address);
+      const minAmount = ethers.parseEther('100');
+
+      await setMinimumTransferAmount(compliance, complianceModule, deployer, countryCode, minAmount);
+      const transferAmount = ethers.parseEther('99');
+      expect(await complianceModule.moduleCheck(bobWallet.address, charlieWallet.address, transferAmount, compliance.target)).to.be.false;
+    });
+
+    it('should allow transfer when no minimum amount is set for country', async () => {
+      const {
+        suite: { compliance, complianceModule },
+        accounts: { aliceWallet, charlieWallet },
+      } = await loadFixture(deployMinTransferByCountryModuleFullSuite);
+
+      expect(await complianceModule.moduleCheck(aliceWallet.address, charlieWallet.address, 1, compliance.target)).to.be.true;
+    });
+
+    it('should allow transfer when user as already a balance', async () => {
+      const {
+        suite: { compliance, complianceModule, identityRegistry },
+        accounts: { deployer, aliceWallet, bobWallet },
+      } = await loadFixture(deployMinTransferByCountryModuleFullSuite);
+
+      const countryCode = await identityRegistry.investorCountry(bobWallet.address);
+      const minAmount = ethers.parseEther('100');
+
+      await setMinimumTransferAmount(compliance, complianceModule, deployer, countryCode, minAmount);
+      expect(await complianceModule.moduleCheck(aliceWallet.address, bobWallet.address, 1, compliance.target)).to.be.true;
+    });
+
+    it('should allow transfer when transfer into same identity and same country with amount below the minimum amount set', async () => {
+      const {
+        suite: { compliance, complianceModule, identityRegistry },
+        accounts: { deployer, aliceWallet, anotherWallet, tokenAgent },
+        identities: { aliceIdentity },
+      } = await loadFixture(deployMinTransferByCountryModuleFullSuite);
+
+      const countryCode = await identityRegistry.investorCountry(aliceWallet.address);
+
+      await identityRegistry.connect(tokenAgent).registerIdentity(anotherWallet.address, aliceIdentity, countryCode);
+
+      const minAmount = ethers.parseEther('100');
+      await setMinimumTransferAmount(compliance, complianceModule, deployer, countryCode, minAmount);
+
+      expect(await complianceModule.moduleCheck(aliceWallet.address, anotherWallet.address, 1, compliance.target)).to.be.true;
+    });
+
+    it('should prevent transfer when transfer into same identity and different country with amount below the minimum amount set', async () => {
+      const {
+        suite: { compliance, complianceModule, identityRegistry },
+        accounts: { deployer, aliceWallet, anotherWallet, tokenAgent },
+        identities: { aliceIdentity },
+      } = await loadFixture(deployMinTransferByCountryModuleFullSuite);
+
+      const countryCode = 1n + (await identityRegistry.investorCountry(aliceWallet.address));
+
+      await identityRegistry.connect(tokenAgent).registerIdentity(anotherWallet.address, aliceIdentity, countryCode);
+
+      const minAmount = ethers.parseEther('100');
+      await setMinimumTransferAmount(compliance, complianceModule, deployer, countryCode, minAmount);
+
+      expect(await complianceModule.moduleCheck(aliceWallet.address, anotherWallet.address, 1, compliance.target)).to.be.false;
+    });
+  });
+});