library issue

contracts/test/TestUniswapV2Library.sol

@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+pragma solidity =0.7.6;
+
+import '../libraries/UniswapV2Library.sol';
+
+contract TestUniswapV2Library {
+    function testEqualityAmountIn(
+        uint256 amountIn,
+        uint256 reserveIn,
+        uint256 reserveOut
+    ) external pure {
+        uint256 amountOut = UniswapV2Library.getAmountOut(amountIn, reserveIn, reserveOut);
+        uint256 amountInComputed = UniswapV2Library.getAmountIn(amountOut, reserveIn, reserveOut);
+        require(amountIn == amountInComputed);
+    }
+
+    function testEqualityAmountOut(
+        uint256 amountOut,
+        uint256 reserveIn,
+        uint256 reserveOut
+    ) external pure {
+        uint256 amountIn = UniswapV2Library.getAmountIn(amountOut, reserveIn, reserveOut);
+        uint256 amountOutComputed = UniswapV2Library.getAmountOut(amountIn, reserveIn, reserveOut);
+        require(amountOut == amountOutComputed);
+    }
+}

test/UniswapV2Library.spec.ts

@@ -0,0 +1,27 @@
+import { ethers } from 'hardhat'
+import { TestUniswapV2Library } from '../typechain'
+
+describe('V2Library', function () {
+  let uniswapLibrary: TestUniswapV2Library
+
+  before(async function () {
+    const factory = await ethers.getContractFactory('TestUniswapV2Library')
+    uniswapLibrary = (await factory.deploy()) as TestUniswapV2Library
+  })
+
+  it('exact in', async () => {
+    await uniswapLibrary.testEqualityAmountIn(
+      '10000000000000000000000',
+      '6060121762013965246271',
+      '1845639706596254478341383'
+    )
+  })
+
+  it('exact out', async () => {
+    await uniswapLibrary.testEqualityAmountOut(
+      '10000000000000000000000',
+      '6060121762013965246271',
+      '1845639706596254478341383'
+    )
+  })
+})