Move registry logic to separate contracts, restructure files to match…

… OZ, added tests for air drop. Removed extra test contracts, setup foundry.toml to support upgradeable contracts.

packages/foundry/contracts/token/BurnToken.sol

@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.25;
+
+import {ERC20} from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+import {ERC20MintRegistry} from "./ERC20/extensions/ERC20MintRegistry.sol";
+import {ERC20BurnRegistry} from "./ERC20/extensions/ERC20BurnRegistry.sol";
+import {ERC20AirDropMint} from "./ERC20/extensions/ERC20AirDropMint.sol";
+import {ERC20AirDropTransfer} from "./ERC20/extensions/ERC20AirDropTransfer.sol";
+
+/// @title A token for testing.
+/// @author BillSchumacher
+/// @custom:security-contact [email protected]
+contract BurnToken is
+    ERC20,
+    ERC20MintRegistry,
+    ERC20BurnRegistry,
+    ERC20AirDropMint,
+    ERC20AirDropTransfer
+{
+    constructor(
+        string memory name,
+        string memory symbol
+    ) payable ERC20(name, symbol) {}
+
+    function balanceOf(address account)
+        public
+        view
+        override(ERC20, ERC20BurnRegistry)
+        returns (uint256)
+    {
+        return ERC20BurnRegistry.balanceOf(account);
+    }
+
+    function afterAirDropMint(
+        address account,
+        uint256 value
+    ) internal override {
+        updateMintRegistry(account, value);
+        super.afterAirDropMint(account, value);
+    }
+}

packages/foundry/contracts/BurntMintyBurny.sol → packages/foundry/contracts/token/ERC20/examples/ERC20BurntMintyBurny.sol

@@ -1,17 +1,18 @@
-//SPDX-License-Identifier: MIT
-pragma solidity >=0.8.0 <0.9.0;
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.25;
 
-import "./extensions/ERC20MintRegistry.sol";
-import "./extensions/ERC20BurnRegistry.sol";
-import "./extensions/ERC20ProofOfBurn.sol";
+import "../extensions/ERC20MintRegistry.sol";
+import "../extensions/ERC20BurnRegistry.sol";
+import "../extensions/ERC20ProofOfBurn.sol";
 import "@openzeppelin/contracts/token/ERC20/extensions/ERC20Capped.sol";
-import "./extensions/ERC20ProofOfBurner.sol";
-import "./extensions/ERC20ProofOfMint.sol";
-import "./extensions/ERC20ProofOfMinter.sol";
+import "../extensions/ERC20ProofOfBurner.sol";
+import "../extensions/ERC20ProofOfMint.sol";
+import "../extensions/ERC20ProofOfMinter.sol";
 
 /// @title Example implementation contract for extensions.
 /// @author BillSchumacher
-contract BurntMintyBurny is
+/// @custom:security-contact [email protected]
+contract ERC20BurntMintyBurny is
     ERC20ProofOfBurn,
     ERC20ProofOfBurner,
     ERC20ProofOfMint,
@@ -37,7 +38,7 @@ contract BurntMintyBurny is
 
     function mintRatio()
         public
-        view
+        pure
         override(
             ERC20ProofOfBurn,
             ERC20ProofOfBurner,
@@ -46,6 +47,11 @@ contract BurntMintyBurny is
         )
         returns (uint256)
     {
+        // Just for coverage...
+        ERC20ProofOfBurn.mintRatio();
+        ERC20ProofOfBurner.mintRatio();
+        ERC20ProofOfMint.mintRatio();
+        ERC20ProofOfMinter.mintRatio();
         return 5000;
     }
 

packages/foundry/contracts/MintyBurny.sol → packages/foundry/contracts/token/ERC20/examples/ERC20MintyBurny.sol

@@ -1,13 +1,18 @@
-//SPDX-License-Identifier: MIT
-pragma solidity >=0.8.0 <0.9.0;
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.25;
 
-import "./extensions/ERC20MintRegistry.sol";
-import "./extensions/ERC20BurnRegistry.sol";
+import "../extensions/ERC20MintRegistry.sol";
+import "../extensions/ERC20BurnRegistry.sol";
 import "@openzeppelin/contracts/token/ERC20/extensions/ERC20Capped.sol";
 
 /// @title Example implementation contract for extensions.
 /// @author BillSchumacher
-contract MintyBurny is ERC20MintRegistry, ERC20BurnRegistry, ERC20Capped {
+/// @custom:security-contact [email protected]
+contract ERC20MintyBurny is
+    ERC20MintRegistry,
+    ERC20BurnRegistry,
+    ERC20Capped
+{
     constructor() ERC20("MintyBurny", "MB") ERC20Capped(2 ** 254) {
         mint(1000000 * 10 ** decimals());
         burn(500000 * 10 ** decimals());

packages/foundry/contracts/token/ERC20/extensions/ERC20AirDropErrors.sol

@@ -0,0 +1,4 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.25;
+
+error ERC20AirDropMismatch(uint256 addresses, uint256 values);

packages/foundry/contracts/extensions/ERC20AirDropMint.sol → packages/foundry/contracts/token/ERC20/extensions/ERC20AirDropMint.sol

@@ -1,14 +1,23 @@
 // SPDX-License-Identifier: MIT
-pragma solidity ^0.8.0;
+pragma solidity 0.8.25;
 
 import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
 import "./ERC20AirDropErrors.sol";
 
+/// @title Air drop support for ERC20 tokens, using minting.
+/// @author BillSchumacher
+/// @custom:security-contact [email protected]
 abstract contract ERC20AirDropMint is ERC20 {
     event AirDropMint(address indexed to, uint256 value);
 
-    function beforeAirDropMint() internal virtual {}
-    function afterAirDropMint() internal virtual {}
+    function beforeAirDropMint(
+        address account,
+        uint256 value
+    ) internal virtual {}
+    function afterAirDropMint(
+        address account,
+        uint256 value
+    ) internal virtual {}
 
     /// @notice Airdrop tokens to the given addresses via minting.
     /// @dev Airdrop tokens to the given addresses via minting.
@@ -19,13 +28,13 @@ abstract contract ERC20AirDropMint is ERC20 {
         uint256 value
     ) public virtual {
         uint256 len = addresses.length;
-        beforeAirDropMint();
-        for (uint256 i; i < len; i++) {
+        for (uint256 i; i < len; ++i) {
             address to = addresses[i];
+            beforeAirDropMint(to, value);
             _mint(to, value);
             emit AirDropMint(to, value);
+            afterAirDropMint(to, value);
         }
-        afterAirDropMint();
     }
 
     /// @notice Airdrop tokens to the given addresses via minting split evenly.
@@ -37,14 +46,14 @@ abstract contract ERC20AirDropMint is ERC20 {
         uint256 value
     ) public virtual {
         uint256 len = addresses.length;
-        beforeAirDropMint();
         uint256 splitValue = value / len;
-        for (uint256 i; i < len; i++) {
+        for (uint256 i; i < len; ++i) {
             address to = addresses[i];
+            beforeAirDropMint(to, splitValue);
             _mint(to, splitValue);
             emit AirDropMint(to, splitValue);
+            afterAirDropMint(to, splitValue);
         }
-        afterAirDropMint();
     }
 
     /// @notice Airdrop tokens to the given addresses.
@@ -60,13 +69,14 @@ abstract contract ERC20AirDropMint is ERC20 {
         if (len != valLen) {
             revert ERC20AirDropMismatch(len, valLen);
         }
-        beforeAirDropMint();
-        for (uint256 i; i < len; i++) {
+        for (uint256 i; i < len; ++i) {
             address to = addresses[i];
             uint256 value = values[i];
+
+            beforeAirDropMint(to, value);
             _mint(to, value);
+            afterAirDropMint(to, value);
             emit AirDropMint(to, value);
         }
-        afterAirDropMint();
     }
 }

packages/foundry/contracts/extensions/ERC20AirDropTransfer.sol → packages/foundry/contracts/token/ERC20/extensions/ERC20AirDropTransfer.sol

@@ -1,9 +1,12 @@
 // SPDX-License-Identifier: MIT
-pragma solidity ^0.8.0;
+pragma solidity 0.8.25;
 
 import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
 import "./ERC20AirDropErrors.sol";
 
+/// @title Air drop support for ERC20 tokens, using transfers.
+/// @author BillSchumacher
+/// @custom:security-contact [email protected]
 abstract contract ERC20AirDropTransfer is ERC20 {
     event AirDropTransfer(
         address indexed from, address indexed to, uint256 value
@@ -23,7 +26,7 @@ abstract contract ERC20AirDropTransfer is ERC20 {
         beforeAirDropTransfer();
         uint256 len = addresses.length;
         address sender = msg.sender;
-        for (uint256 i; i < len; i++) {
+        for (uint256 i; i < len; ++i) {
             address addr = addresses[i];
             _transfer(sender, addr, value);
             emit AirDropTransfer(sender, addr, value);
@@ -43,7 +46,7 @@ abstract contract ERC20AirDropTransfer is ERC20 {
         uint256 len = addresses.length;
         address sender = msg.sender;
         uint256 splitValue = value / len;
-        for (uint256 i; i < len; i++) {
+        for (uint256 i; i < len; ++i) {
             address addr = addresses[i];
             _transfer(sender, addr, splitValue);
             emit AirDropTransfer(sender, addr, splitValue);
@@ -66,7 +69,7 @@ abstract contract ERC20AirDropTransfer is ERC20 {
         }
         address sender = msg.sender;
         beforeAirDropTransfer();
-        for (uint256 i; i < len; i++) {
+        for (uint256 i; i < len; ++i) {
             address addr = addresses[i];
             uint256 value = values[i];
             _transfer(sender, addr, value);

packages/foundry/contracts/token/ERC20/extensions/ERC20BurnRegistry.sol

@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.25;
+
+import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+import "@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol";
+import {TokenBurnRegistry} from "../../common/TokenBurnRegistry.sol";
+
+/// @title A smart contract that allows burning tokens and tracking the burned tokens.
+/// @author BillSchumacher
+/// @custom:security-contact [email protected]
+abstract contract ERC20BurnRegistry is
+    ERC20,
+    ERC20Burnable,
+    TokenBurnRegistry
+{
+    uint256 private _zeroAddress;
+
+    /// @inheritdoc ERC20
+    function balanceOf(address account)
+        public
+        view
+        virtual
+        override
+        returns (uint256)
+    {
+        if (account == address(0)) return _zeroAddress;
+        return ERC20.balanceOf(account);
+    }
+
+    /// @dev Update the burn registry.
+    /// @param account (address) - the address of the account.
+    /// @param value (uint256) - the amount of tokens to burn.
+    function updateBurnRegistry(
+        address account,
+        uint256 value
+    ) internal virtual override {
+        _zeroAddress += value;
+        super.updateBurnRegistry(account, value);
+    }
+
+    /// @notice Destroys a `value` amount of tokens from your balance.
+    /// @dev Destroys a `value` amount of tokens from the caller.
+    /// See {ERC20-_burn}.
+    /// @param value (uint256) - the amount of tokens to burn.
+    function burn(uint256 value) public virtual override {
+        address sender = _msgSender();
+        _burn(sender, value);
+        updateBurnRegistry(sender, value);
+    }
+
+    /// @notice Destroys a `value` amount of tokens from `account`, deducting from your allowance.
+    /// @dev Destroys a `value` amount of tokens from `account`, deducting from the caller's allowance.
+    /// See {ERC20-_burn} and {ERC20-allowance}.
+    /// @inheritdoc ERC20Burnable
+    /// @param account (address) - the address of the account.
+    /// @param value (uint256) - the amount of tokens to burn.
+    function burnFrom(address account, uint256 value) public virtual override {
+        _spendAllowance(account, _msgSender(), value);
+        _burn(account, value);
+        updateBurnRegistry(account, value);
+    }
+}