Test getReserves() on USDC-WETH pair on Ropsen

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1

I have a func to get eth price from uniswap pair USDC-WETH but could’t really test on Ropsten. The pair address is here https://ropsten.etherscan.io/address/0x7cae76c0517ddca4c10bf023b607b4db92114b41#readContract

However, getReserves() will give me (0,0,) for the pair ratio. How can I test a close to mainnet ratio for this pair? Thanks

2

Emmm, it seems like there is not any reserves in this pair contract, so maybe you can try to add some liquidity and then call this function

1 Like
3

I’m trying to add lidquidity to USDC-WETH pair on Ropsten through Truffle js script but couldn’t quite get it working with this error: Error: IUniswapV2Router02 has not been deployed to detected network (network/artifact mismatch)

module.exports = async function main(callback) {
    try {
        const IUniswapV2Pair = artifacts.require("IUniswapV2Pair");
        const IUniswapV2Factory = artifacts.require("IUniswapV2Factory");
        const IUniswapV2Router01 = artifacts.require("IUniswapV2Router01");
        const IUniswapV2Router02 = artifacts.require("IUniswapV2Router02");

        const uniswapV2Router = await IUniswapV2Router02.deployed('0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D');
        
        uniswapV2Router.approve('0x7cae76c0517ddca4c10bf023b607b4db92114b41', 1000);

        uniswapV2Router.addLiquidityETH(
            '0x7cae76c0517ddca4c10bf023b607b4db92114b41',
            3,
            3, // slippage is unavoidable
            1, // slippage is unavoidable
            owner(),
            block.timestamp
        );

        callback(0);
    } catch (error) {
        console.error(error);
        callback(1);
    }
4

Do you use truffle to run script or web3.js? I think for truffle, it should be

const uniswapV2Router = await UniswapV2Router02.at('0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D');

And if you use web3.js, it should be:
const uniswapV2Router = await new web3.eth.Contract(Contract_Interface, Contract_address)`
But there is a more easier to do this, you can add liquidity by the website of the Uniswap with the Ropsten network.

1 Like
5

Thank you. I’m using truffle to run the js script. Truffle documentation is quite lacking. How did you know it is UniswapV2Router02.at?

How do I use uniswap front end website on ropsten test net? I only see mainnet.

6

Just change your network to the Ropsten.