✨ Vault beginnings

Makefile

@@ -1,6 +1,7 @@
 # Dapp Build Config.
 export DAPP_BUILD_OPTIMIZE=1
 export DAPP_BUILD_OPTIMIZE_RUNS=1000000000
+export DAPP_TEST_FUZZ_RUNS=5000
 
 # Install, update, build and test everything.
 all: solc install update build test

README.md

@@ -19,7 +19,7 @@
 
 - First, install Nix:
 
-```sh
+```
 # User must be in sudoers
 curl -L https://nixos.org/nix/install | sh
 
@@ -29,7 +29,7 @@ curl -L https://nixos.org/nix/install | sh
 
 - Then, install dapptools:
 
-```sh
+```
 curl https://dapp.tools/install | sh
 ```
 
@@ -54,15 +54,15 @@ make
 
 #### Compiling
 
-```sh
+```
 make build # or 'dapp build'
 ```
 
 Compiles the project.
 
 #### Testing
 
-```sh
+```
 make test # or 'dapp test --verbosity 1'
 ```
 
@@ -72,14 +72,14 @@ Test the project and only log verbose info for failed tests.
 
 Test the project and log verbose info for everything.
 
-```sh
+```
 make vtest # or 'dapp test --verbosity 3'
 ```
 
 #### Debugging
 
-```sh
-mak debug # or 'dapp debug'
+```
+make debug # or 'dapp debug'
 ```
 
 Run a test using the HEVM interactive debugger.

src/Vault.sol

@@ -1,9 +1,13 @@
 // SPDX-License-Identifier: UNLICENSED
 pragma solidity 0.8.6;
 
-import "./libraries/ERC20.sol";
+import "./external/ERC20.sol";
 import "./libraries/StringConcat.sol";
 
+/// @title Fuse Vault/fvToken
+/// @author TransmissionsDev + JetJadeja
+/// @notice Yield bearing token that enables users to swap their
+/// underlying asset for fvTokens to instantly begin earning yield.
 contract Vault is ERC20 {
   /// @notice The underlying token for the vault.
   ERC20 public immutable underlying;
@@ -20,4 +24,23 @@ contract Vault is ERC20 {
   {
     underlying = _underlying;
   }
+
+  /// @notice Deposits an underlying token and mints fvTokens.
+  /// @param amount The amount of the underlying token to deposit.
+  function deposit(uint256 amount) external {
+    _mint(msg.sender, amount);
+
+    // Transfer in underlying tokens from the sender.
+    underlying.transferFrom(msg.sender, address(this), amount);
+  }
+
+  /// @notice Burns fvTokens and sends underlying tokens to the sender.
+  /// @param amount The amount of fvTokens to burn.
+  function withdraw(uint256 amount) external {
+    // This will revert if the user does not have enough fvTokens.
+    _burn(msg.sender, amount);
+
+    // Transfer underlying tokens to the sender.
+    underlying.transfer(msg.sender, amount);
+  }
 }

src/libraries/ERC20.sol → src/external/ERC20.sol

@@ -1,129 +1,7 @@
 // SPDX-License-Identifier: MIT
-
 pragma solidity ^0.8.0;
 
-/*
- * @dev Provides information about the current execution context, including the
- * sender of the transaction and its data. While these are generally available
- * via msg.sender and msg.data, they should not be accessed in such a direct
- * manner, since when dealing with meta-transactions the account sending and
- * paying for execution may not be the actual sender (as far as an application
- * is concerned).
- *
- * This contract is only required for intermediate, library-like contracts.
- */
-abstract contract Context {
-  function _msgSender() internal view virtual returns (address) {
-    return msg.sender;
-  }
-
-  function _msgData() internal view virtual returns (bytes calldata) {
-    return msg.data;
-  }
-}
-
-/**
- * @dev Interface of the ERC20 standard as defined in the EIP.
- */
-interface IERC20 {
-  /**
-   * @dev Returns the amount of tokens in existence.
-   */
-  function totalSupply() external view returns (uint256);
-
-  /**
-   * @dev Returns the amount of tokens owned by `account`.
-   */
-  function balanceOf(address account) external view returns (uint256);
-
-  /**
-   * @dev Moves `amount` tokens from the caller's account to `recipient`.
-   *
-   * Returns a boolean value indicating whether the operation succeeded.
-   *
-   * Emits a {Transfer} event.
-   */
-  function transfer(address recipient, uint256 amount) external returns (bool);
-
-  /**
-   * @dev Returns the remaining number of tokens that `spender` will be
-   * allowed to spend on behalf of `owner` through {transferFrom}. This is
-   * zero by default.
-   *
-   * This value changes when {approve} or {transferFrom} are called.
-   */
-  function allowance(address owner, address spender)
-    external
-    view
-    returns (uint256);
-
-  /**
-   * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
-   *
-   * Returns a boolean value indicating whether the operation succeeded.
-   *
-   * IMPORTANT: Beware that changing an allowance with this method brings the risk
-   * that someone may use both the old and the new allowance by unfortunate
-   * transaction ordering. One possible solution to mitigate this race
-   * condition is to first reduce the spender's allowance to 0 and set the
-   * desired value afterwards:
-   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
-   *
-   * Emits an {Approval} event.
-   */
-  function approve(address spender, uint256 amount) external returns (bool);
-
-  /**
-   * @dev Moves `amount` tokens from `sender` to `recipient` using the
-   * allowance mechanism. `amount` is then deducted from the caller's
-   * allowance.
-   *
-   * Returns a boolean value indicating whether the operation succeeded.
-   *
-   * Emits a {Transfer} event.
-   */
-  function transferFrom(
-    address sender,
-    address recipient,
-    uint256 amount
-  ) external returns (bool);
-
-  /**
-   * @dev Emitted when `value` tokens are moved from one account (`from`) to
-   * another (`to`).
-   *
-   * Note that `value` may be zero.
-   */
-  event Transfer(address indexed from, address indexed to, uint256 value);
-
-  /**
-   * @dev Emitted when the allowance of a `spender` for an `owner` is set by
-   * a call to {approve}. `value` is the new allowance.
-   */
-  event Approval(address indexed owner, address indexed spender, uint256 value);
-}
-
-/**
- * @dev Interface for the optional metadata functions from the ERC20 standard.
- *
- * _Available since v4.1._
- */
-interface IERC20Metadata is IERC20 {
-  /**
-   * @dev Returns the name of the token.
-   */
-  function name() external view returns (string memory);
-
-  /**
-   * @dev Returns the symbol of the token.
-   */
-  function symbol() external view returns (string memory);
-
-  /**
-   * @dev Returns the decimals places of the token.
-   */
-  function decimals() external view returns (uint8);
-}
+import "../interfaces/IERC20.sol";
 
 /**
  * @dev Implementation of the {IERC20} interface.
@@ -149,7 +27,7 @@ interface IERC20Metadata is IERC20 {
  * functions have been added to mitigate the well-known issues around setting
  * allowances. See {IERC20-approve}.
  */
-contract ERC20 is Context, IERC20, IERC20Metadata {
+contract ERC20 is IERC20, IERC20Metadata {
   mapping(address => uint256) private _balances;
 
   mapping(address => mapping(address => uint256)) private _allowances;
@@ -239,7 +117,7 @@ contract ERC20 is Context, IERC20, IERC20Metadata {
     override
     returns (bool)
   {
-    _transfer(_msgSender(), recipient, amount);
+    _transfer(msg.sender, recipient, amount);
     return true;
   }
 
@@ -269,7 +147,7 @@ contract ERC20 is Context, IERC20, IERC20Metadata {
     override
     returns (bool)
   {
-    _approve(_msgSender(), spender, amount);
+    _approve(msg.sender, spender, amount);
     return true;
   }
 
@@ -293,13 +171,13 @@ contract ERC20 is Context, IERC20, IERC20Metadata {
   ) public virtual override returns (bool) {
     _transfer(sender, recipient, amount);
 
-    uint256 currentAllowance = _allowances[sender][_msgSender()];
+    uint256 currentAllowance = _allowances[sender][msg.sender];
     require(
       currentAllowance >= amount,
       "ERC20: transfer amount exceeds allowance"
     );
     unchecked {
-      _approve(sender, _msgSender(), currentAllowance - amount);
+      _approve(sender, msg.sender, currentAllowance - amount);
     }
 
     return true;
@@ -323,9 +201,9 @@ contract ERC20 is Context, IERC20, IERC20Metadata {
     returns (bool)
   {
     _approve(
-      _msgSender(),
+      msg.sender,
       spender,
-      _allowances[_msgSender()][spender] + addedValue
+      _allowances[msg.sender][spender] + addedValue
     );
     return true;
   }
@@ -349,13 +227,13 @@ contract ERC20 is Context, IERC20, IERC20Metadata {
     virtual
     returns (bool)
   {
-    uint256 currentAllowance = _allowances[_msgSender()][spender];
+    uint256 currentAllowance = _allowances[msg.sender][spender];
     require(
       currentAllowance >= subtractedValue,
       "ERC20: decreased allowance below zero"
     );
     unchecked {
-      _approve(_msgSender(), spender, currentAllowance - subtractedValue);
+      _approve(msg.sender, spender, currentAllowance - subtractedValue);
     }
 
     return true;