feat: Simple Wrapper

.gitmodules

@@ -2,3 +2,6 @@
 	path = lib/forge-std
 	url = https://github.com/foundry-rs/forge-std
 	branch = v1
+[submodule "lib/common"]
+	path = lib/common
+	url = git@github.com:MZero-Labs/common.git

.prettierrc

@@ -1,16 +1,17 @@
 {
-  "plugins": ["prettier-plugin-solidity"],
+  "plugins": [
+    "prettier-plugin-solidity"
+  ],
   "overrides": [
     {
       "files": "*.sol",
       "options": {
         "bracketSpacing": true,
-        "compiler": "0.8.25",
+        "compiler": "0.8.23",
         "parser": "solidity-parse",
         "printWidth": 120,
         "tabWidth": 4,
       }
     }
   ]
 }
-

.solhint.json

@@ -1,10 +1,20 @@
 {
-  "extends": ["solhint:recommended"],
-  "plugins": ["prettier"],
+  "extends": [
+    "solhint:recommended"
+  ],
+  "plugins": [
+    "prettier"
+  ],
   "rules": {
     "prettier/prettier": "error",
-    "code-complexity": ["warn", 10],
-    "compiler-version": ["error", "0.8.25"],
+    "code-complexity": [
+      "warn",
+      10
+    ],
+    "compiler-version": [
+      "error",
+      "0.8.23"
+    ],
     "comprehensive-interface": "off",
     "const-name-snakecase": "off",
     "func-name-mixedcase": "off",
@@ -14,10 +24,16 @@
         "ignoreConstructors": true
       }
     ],
-    "function-max-lines": ["warn", 100],
+    "function-max-lines": [
+      "warn",
+      100
+    ],
     "immutable-vars-naming": "off",
     "imports-on-top": "error",
-    "max-line-length": ["warn", 120],
+    "max-line-length": [
+      "warn",
+      120
+    ],
     "no-empty-blocks": "off",
     "no-inline-assembly": "off",
     "not-rely-on-time": "off",

foundry.toml

@@ -3,7 +3,7 @@ gas_reports = ["*"]
 gas_reports_ignore = []
 ignored_error_codes = []
 optimizer = false
-solc_version = "0.8.25"
+solc_version = "0.8.23"
 verbosity = 3
 
 [profile.production]

src/WrappedM.sol

@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-3.0
+
+pragma solidity 0.8.23;
+
+import { UIntMath } from "../lib/common/src/libs/UIntMath.sol";
+
+import { IERC20 } from "../lib/common/src/interfaces/IERC20.sol";
+
+import { ERC20Extended } from "../lib/common/src/ERC20Extended.sol";
+
+import { IMTokenLike } from "./interfaces/IMTokenLike.sol";
+import { IWrappedM } from "./interfaces/IWrappedM.sol";
+
+contract WrappedM is IWrappedM, ERC20Extended {
+    /* ============ Variables ============ */
+
+    uint56 internal constant _EXP_SCALED_ONE = 1e12;
+
+    address public immutable mToken;
+
+    uint256 public totalSupply;
+
+    mapping(address account => uint256 balance) public balanceOf;
+
+    /* ============ Modifiers ============ */
+
+    modifier onlyEarner() {
+        if (!IMTokenLike(mToken).isEarning(msg.sender)) revert NotEarner();
+
+        _;
+    }
+
+    /* ============ Constructor ============ */
+
+    constructor(address mToken_) ERC20Extended("WrappedM by M^0", "wM", 6) {
+        mToken = mToken_;
+    }
+
+    /* ============ Interactive Functions ============ */
+
+    function deposit(address account_, uint256 amount_) external onlyEarner returns (uint256 shares_) {
+        shares_ = _getPrincipalAmountRoundedDown(UIntMath.safe240(amount_), IMTokenLike(mToken).currentIndex());
+
+        emit Transfer(address(0), account_, shares_);
+
+        balanceOf[account_] += shares_;
+        totalSupply += shares_;
+
+        IERC20(mToken).transferFrom(msg.sender, address(this), amount_);
+    }
+
+    function withdraw(address account_, uint256 shares_) external {
+        emit Transfer(account_, address(0), shares_);
+
+        uint256 amount_ = _getPresentAmountRoundedDown(UIntMath.safe112(shares_), IMTokenLike(mToken).currentIndex());
+
+        balanceOf[account_] += shares_;
+        totalSupply += shares_;
+
+        IERC20(mToken).transferFrom(address(this), msg.sender, amount_);
+    }
+
+    /* ============ View/Pure Functions ============ */
+
+    /* ============ Internal Interactive Functions ============ */
+
+    function _transfer(address sender_, address recipient_, uint256 amount_) internal override {
+        emit Transfer(sender_, recipient_, amount_);
+
+        balanceOf[sender_] -= amount_;
+        balanceOf[recipient_] += amount_;
+    }
+
+    /* ============ Internal View/Pure Functions ============ */
+
+    function _multiplyDown(uint112 x_, uint128 index_) internal pure returns (uint240) {
+        unchecked {
+            return uint240((uint256(x_) * index_) / _EXP_SCALED_ONE);
+        }
+    }
+
+    function _divideDown(uint240 x_, uint128 index_) internal pure returns (uint112 z) {
+        if (index_ == 0) revert DivisionByZero();
+
+        unchecked {
+            return UIntMath.safe112((uint256(x_) * _EXP_SCALED_ONE) / index_);
+        }
+    }
+
+    function _getPresentAmountRoundedDown(uint112 principalAmount_, uint128 index_) internal pure returns (uint240) {
+        return _multiplyDown(principalAmount_, index_);
+    }
+
+    function _getPrincipalAmountRoundedDown(uint240 presentAmount_, uint128 index_) internal pure returns (uint112) {
+        return _divideDown(presentAmount_, index_);
+    }
+}

src/interfaces/IMTokenLike.sol

@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: GPL-3.0
+
+pragma solidity 0.8.23;
+
+interface IMTokenLike {
+    /* ============ View/Pure Functions ============ */
+
+    function currentIndex() external view returns (uint128);
+
+    function isEarning(address account) external view returns (bool);
+}

src/interfaces/IWrappedM.sol

@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-3.0
+
+pragma solidity 0.8.23;
+
+import { IERC20Extended } from "../../lib/common/src/interfaces/IERC20Extended.sol";
+
+interface IWrappedM is IERC20Extended {
+    /* ============ Events ============ */
+
+    /* ============ Custom Errors ============ */
+
+    error NotEarner();
+
+    error DivisionByZero();
+
+    /* ============ Interactive Functions ============ */
+
+    function deposit(address account, uint256 amount) external returns (uint256 shares);
+
+    function withdraw(address account, uint256 shares) external;
+
+    /* ============ View/Pure Functions ============ */
+
+    function mToken() external view returns (address);
+}