Reserves are not changed after swap tokens

Question

I forked Fantom network. And I use UniswapV2Router02, WrappedFtm, Btc contracts deployed on Fantom network in my test scripts.

This is test scripits.

    beforeEach(async () => {
        [owner, account1, account2] = await ethers.getSigners();
        const myContract = await ethers.getContractFactory(
          "MyContract"
        );
        MyContract = await myContract.deploy();
        await MyContract.deployed();
    
        const UniswapAbi = require("./UniswapV2Router02.json");
        UniswapRouter = new ethers.Contract(UNISWAPV2ROUTER02, UniswapAbi, owner);
    
        const FtmAbi = require("./WrappedFtm.json");
        WrappedFtm = new ethers.Contract(FTM, FtmAbi, owner);
    });
    
    describe("Test", () => {
        beforeEach(async () => {
          await WrappedFtm.deposit({ value: "2000000000000000000" });
          await WrappedFtm.approve(UniswapRouter.address, "2000000000000000000");
        });
    
        it("getCurrentPrice test", async () => {
          await MyContract.setFeedAddress(FTM_USD_FEED, BTC_USD_FEED);
          await MyContract.getCurrentPrice(FTM_BTC_LP);
          const amount = await UniswapRouter.swapExactTokensForTokens(
            "1000000000000000000",
            1,
            [FTM, WBTC],
            owner.address,
            Date.now() + 100000
          );
          console.log({ amount });
          await MyContract.getCurrentPrice(FTM_BTC_LP);
        });
    });

This is my contract.

    // SPDX-License-Identifier: UNLICENSED
    pragma solidity ^0.8.0;
    
    import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
    import "@uniswap/v2-core/contracts/interfaces/IUniswapV2Pair.sol";
    import "hardhat/console.sol";
    
    contract MyContract {
        uint public version;
        address public token0FeedAddress;
        address public token1FeedAddress;
    
        constructor() {
            version = 1;
        }
        
        function getCurrentPrice(address token) external view returns(uint) {
            address token0Address = IUniswapV2Pair(token).token0();
            address token1Address = IUniswapV2Pair(token).token1();
            (
                uint reserve0,
                uint reserve1,
                // uint blockTimestampLast
            ) = IUniswapV2Pair(token).getReserves();
            console.log(reserve0, reserve1);
        }
    
        function setFeedAddress(address feedAddress0, address feedAddress1) external {
            token0FeedAddress = feedAddress0;
            token1FeedAddress = feedAddress1;
        }
    }

In getCurretPrice function, I logged reserves of token0 and token1 but they are not changed after swap tokens. Please someone help me.

Answer 1

Fixed. The factory addresses of IUniswapV2Router02 and IUniswapV2Pair were different.

Answer 2

A swap should not change the total supply of an ERC20 token. The total supply should stay exactly the same. Only the accounts holding the tokens will change because of the swap, not how many tokens are circulating.