build: uni v2 extended

src/swappers/UniswapV2Extended.sol

@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity 0.8.18;
+
+import {UniswapV2Swapper, IUniswapV2Router02} from "./UniswapV2Swapper.sol";
+
+/**
+ *   @title UniswapV2Extended
+ *   @author Yearn.finance
+ *   @dev This is a simple contract that can be inherited by any tokenized
+ *   strategy that would like to use more Uniswap V2 functions than just
+ *   an exact swap from of erc-20 tokens.
+ *
+ *   This contract will give access to all other Uni V2 functionality
+ *   with the ease of one internal function call.
+ */
+contract UniswapV2Extended is UniswapV2Swapper {
+    /**
+     * @dev Used to swap a specific amount of `_to` from `_from` unless
+     * it takes more than `_maxAmountFrom`.
+     *
+     * This will check and handle all allownaces as well as not swapping
+     * unless `_maxAmountFrom` is greater than the set `minAmountToSell`
+     *
+     * If one of the tokens matches with the `base` token it will do only
+     * one jump, otherwise will do two jumps.
+     *
+     * @param _from The token we are swapping from.
+     * @param _to The token we are swapping to.
+     * @param _amountTo The amount of `_to` we need out.
+     * @param _maxAmountFrom The max of `_from` we will swap.
+     */
+    function _swapTo(
+        address _from,
+        address _to,
+        uint256 _amountTo,
+        uint256 _maxAmountFrom
+    ) internal {
+        if (_maxAmountFrom > minAmountToSell) {
+            _checkAllowance(router, _from, _maxAmountFrom);
+
+            IUniswapV2Router02(router).swapTokensForExactTokens(
+                _amountTo,
+                _maxAmountFrom,
+                _getTokenOutPath(_from, _to),
+                address(this),
+                block.timestamp
+            );
+        }
+    }
+}