From 82ced894cf76c62084edee68ebf0db3894d0c21e Mon Sep 17 00:00:00 2001
From: Sahil-Gujrati <sahilgujrati12@gmail.com>
Date: Fri, 22 Mar 2024 16:12:57 +0530
Subject: [PATCH] test: Finish testing flash swaps

---
 test/unit/flashSwapTests/FlashSwap.t.sol | 221 +++++++++++++++++++++++
 1 file changed, 221 insertions(+)
 create mode 100644 test/unit/flashSwapTests/FlashSwap.t.sol

diff --git a/test/unit/flashSwapTests/FlashSwap.t.sol b/test/unit/flashSwapTests/FlashSwap.t.sol
new file mode 100644
index 0000000..eb1cae9
--- /dev/null
+++ b/test/unit/flashSwapTests/FlashSwap.t.sol
@@ -0,0 +1,221 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.20;
+
+import {FlashSwapHelper} from "../../utils/helpers/FlashSwapHelper.sol";
+import { ThunderSwapper } from "../../utils/ThunderSwapper.sol";
+import { UniversalHelper } from "../../utils/helpers/UniversalHelper.sol";
+
+contract FlashSwap is UniversalHelper, FlashSwapHelper {
+    ThunderSwapper private thunderSwapper;
+
+    modifier deployThunderSwapper() {
+        vm.startPrank(user1);
+        thunderSwapper =
+            new ThunderSwapper(address(tokenA), address(tokenB), address(thunderSwapPool));
+        vm.stopPrank();
+        _;
+    }
+
+    function testFlashSwappingExactInputDoesNotBreakInvariant()
+        public
+        distributeTokensToUsers(2e18, 4e18)
+        addInitialLiquidity(1e18, 2e18)
+        deployThunderSwapper
+    {
+        uint256 inputAmount = 1e18;
+        uint256 minimumOutputTokensToReceive = 5e17;
+        uint256 initialInvariantValue =
+            tokenA.balanceOf(address(thunderSwapPool)) * tokenB.balanceOf(address(thunderSwapPool));
+
+        vm.startPrank(user1);
+        tokenA.transfer(address(thunderSwapper), tokenA.balanceOf(user1));
+        thunderSwapPool.flashSwapExactInput(
+            tokenA,
+            inputAmount,
+            minimumOutputTokensToReceive,
+            address(thunderSwapper),
+            true,
+            uint256(block.timestamp)
+        );
+        vm.stopPrank();
+
+        uint256 finalInvariantValue =
+            tokenA.balanceOf(address(thunderSwapPool)) * tokenB.balanceOf(address(thunderSwapPool));
+        assert(finalInvariantValue > initialInvariantValue);
+    }
+
+    function testFlashSwappingExactOutputDoesNotBreakInvariant()
+        public
+        distributeTokensToUsers(2e18, 4e18)
+        addInitialLiquidity(1e18, 2e18)
+        deployThunderSwapper
+    {
+        uint256 outputAmount = 5e17;
+        uint256 maximumInputTokensToSend = 3e18;
+        uint256 initialInvariantValue =
+            tokenA.balanceOf(address(thunderSwapPool)) * tokenB.balanceOf(address(thunderSwapPool));
+
+        vm.startPrank(user1);
+        tokenB.transfer(address(thunderSwapper), tokenB.balanceOf(user1));
+        thunderSwapPool.flashSwapExactOutput(
+            tokenA,
+            outputAmount,
+            maximumInputTokensToSend,
+            address(thunderSwapper),
+            true,
+            uint256(block.timestamp)
+        );
+        vm.stopPrank();
+
+        uint256 finalInvariantValue =
+            tokenA.balanceOf(address(thunderSwapPool)) * tokenB.balanceOf(address(thunderSwapPool));
+        assert(finalInvariantValue > initialInvariantValue);
+    }
+
+    function flashSwappingEmitsEvent()
+        public
+        distributeTokensToUsers(2e18, 4e18)
+        addInitialLiquidity(1e18, 2e18)
+        deployThunderSwapper
+    {
+        uint256 inputAmount = 1e18;
+        uint256 minimumOutputTokensToReceive = 5e17;
+
+        vm.startPrank(user1);
+        tokenA.transfer(address(thunderSwapper), tokenA.balanceOf(user1));
+        vm.expectEmit(true, true, true, false);
+        emit FlashSwapped(user1, tokenA, tokenB,inputAmount, thunderSwapPool.getOutputBasedOnInput(inputAmount, tokenA.balanceOf(address(thunderSwapPool)), tokenB.balanceOf(address(thunderSwapPool))));
+        thunderSwapPool.flashSwapExactInput(
+            tokenA,
+            inputAmount,
+            minimumOutputTokensToReceive,
+            address(thunderSwapper),
+            true,
+            uint256(block.timestamp)
+        );
+        vm.stopPrank();
+    }
+
+    function flashSwappingRevertsIfInputOrOutputAmountsAreZero()
+        public
+        deployThunderSwapper
+    {
+        vm.expectRevert(InputValueZeroNotAllowed.selector);
+        thunderSwapPool.flashSwapExactInput(
+            tokenA,
+            0,
+            0,
+            address(thunderSwapper),
+            true,
+            uint256(block.timestamp)
+        );
+
+        vm.expectRevert(InputValueZeroNotAllowed.selector);
+        thunderSwapPool.flashSwapExactOutput(
+            tokenA,
+            0,
+            0,
+            address(thunderSwapper),
+            true,
+            uint256(block.timestamp)
+        );
+    }
+
+    function flashSwappingRevertsIfDeadlinePassed()
+        public
+        deployThunderSwapper
+    {
+        uint256 dummyValue1 = 1e18;
+        uint256 dummyValue2 = 2e18;
+
+        vm.warp(1 days);
+        uint256 deadline = uint256(block.timestamp - 1);
+        vm.expectRevert(abi.encodeWithSelector(DeadlinePassed.selector, deadline));
+        thunderSwapPool.flashSwapExactInput(
+            tokenA,
+            dummyValue1,
+            dummyValue2,
+            address(thunderSwapper),
+            true,
+            deadline
+        );
+
+        vm.expectRevert(abi.encodeWithSelector(DeadlinePassed.selector, deadline));
+        thunderSwapPool.flashSwapExactOutput(
+            tokenA,
+            dummyValue1,
+            dummyValue2,
+            address(thunderSwapper),
+            true,
+            deadline
+        );
+    }
+
+    function flashSwappingRevertsIfReceiverAddressIsZero() public {
+        uint256 dummyValue1 = 1e18;
+        uint256 dummyValue2 = 2e18;
+
+        vm.expectRevert(ReceiverZeroAddress.selector);
+        thunderSwapPool.flashSwapExactInput(
+            tokenA,
+            dummyValue1,
+            dummyValue2,
+            address(0),
+            true,
+            uint256(block.timestamp)
+        );
+
+        vm.expectRevert(ReceiverZeroAddress.selector);
+        thunderSwapPool.flashSwapExactOutput(
+            tokenA,
+            dummyValue1,
+            dummyValue2,
+            address(0),
+            true,
+            uint256(block.timestamp)
+        );
+    }
+
+    function flashSwappingExactInputRevertsIfOutputAmountisLessThanMinimumOutputAmountToReceive() public distributeTokensToUsers(1e18, 2e18) addInitialLiquidity(1e18, 2e18) {
+        uint256 inputAmount = 1e18;
+        uint256 minimumOutputTokensToReceive = 5e18;
+        uint256 calculatedOutputAmount = thunderSwapPool.getOutputBasedOnInput(inputAmount, tokenA.balanceOf(address(thunderSwapPool)), tokenB.balanceOf(address(thunderSwapPool)));
+
+        vm.startPrank(user1);
+        tokenA.transfer(address(thunderSwapper), tokenA.balanceOf(user1));
+        vm.expectRevert(abi.encodeWithSelector(PoolTokenToReceiveLessThanMinimumPoolTokenToReceive.selector, tokenB, calculatedOutputAmount, minimumOutputTokensToReceive));
+        thunderSwapPool.flashSwapExactInput(
+            tokenA,
+            inputAmount,
+            minimumOutputTokensToReceive,
+            address(thunderSwapper),
+            true,
+            uint256(block.timestamp)
+        );
+        vm.stopPrank();
+    }
+
+    function testFlashSwappingExactOutputRevertsIfInputAmountisGreaterThanMaximumInputAmountToSend()
+        public
+        distributeTokensToUsers(2e18, 4e18)
+        addInitialLiquidity(1e18, 2e18)
+        deployThunderSwapper
+    {
+        uint256 outputAmount = 5e17;
+        uint256 maximumInputTokensToSend = 1e18;
+        uint256 calculatedInputAmount = thunderSwapPool.getInputBasedOnOuput(outputAmount, tokenB.balanceOf(address(thunderSwapPool)), tokenA.balanceOf(address(thunderSwapPool)));
+
+        vm.startPrank(user1);
+        tokenB.transfer(address(thunderSwapper), tokenB.balanceOf(user1));
+        vm.expectRevert(abi.encodeWithSelector(PoolTokenToSendMoreThanMaximumPoolTokenToSend.selector, tokenB, calculatedInputAmount, maximumInputTokensToSend));
+        thunderSwapPool.flashSwapExactOutput(
+            tokenA,
+            outputAmount,
+            maximumInputTokensToSend,
+            address(thunderSwapper),
+            true,
+            uint256(block.timestamp)
+        );
+        vm.stopPrank();
+    }
+}