call revert exception - method="getAmountsOut(uint256,address[])

[lucashenning]

First off, thanks for this great helper library! It saves a ton of time and effort when it comes to interacting with the uniswap sdk. I'm trying to swap from USDC to DAI on ropsten and everything is working fine when I submit the transaction manually, however, I'm getting a contract call error from the getAmountsOut() function in the uniswap contract.

swapTokens(
        signer, // ethers signer
        inputAddr, // input token address
        outputAddr, // output token address
        amount, // ammount to buy or sell with decimals
        true, // true if amount is input token, false if amount is output token
        {
          //recipient: '', // optional recipient address (default to signer)
          //maxSlippage: 100, // optional frontrunning tolerance (default to 100 basis points)
          //maxDelay: 60 * 2, // optional max settlement time in seconds (default to 2 minutes)
        },
    )

Here are the addresses that I'm using:

const USDC = '0x0D9C8723B343A8368BebE0B5E89273fF8D712e3C'; // USDC Address
const DAI = '0xad6d458402f60fd3bd25163575031acdce07538d';
const amount = '1.0';

This is the error:

Error: call revert exception (method="getAmountsOut(uint256,address[])", errorSignature=null, errorArgs=[null], reason=null, code=CALL_EXCEPTION, version=abi/5.0.5)
    at Logger.makeError (/Users/lucas/Desktop/SukuLab/twilio-suku/node_modules/@ethersproject/logger/lib/index.js:179:21)
    at Logger.throwError (/Users/lucas/Desktop/SukuLab/twilio-suku/node_modules/@ethersproject/logger/lib/index.js:188:20)
    at Interface.decodeFunctionResult (/Users/lucas/Desktop/SukuLab/twilio-suku/node_modules/@ethersproject/abi/lib/interface.js:286:23)
    at Contract.<anonymous> (/Users/lucas/Desktop/SukuLab/twilio-suku/node_modules/@ethersproject/contracts/lib/index.js:300:56)
    at step (/Users/lucas/Desktop/SukuLab/twilio-suku/node_modules/@ethersproject/contracts/lib/index.js:46:23)
    at Object.next (/Users/lucas/Desktop/SukuLab/twilio-suku/node_modules/@ethersproject/contracts/lib/index.js:27:53)
    at fulfilled (/Users/lucas/Desktop/SukuLab/twilio-suku/node_modules/@ethersproject/contracts/lib/index.js:18:58)
    at processTicksAndRejections (internal/process/task_queues.js:97:5)

Seems like the getAmountsOut() function in the uniswap contract is throwing. Any idea what might be causing this issue?

[thegostep]

Here are the addresses that I'm using:

@lucashenning which network are you targeting?

Here are the mainnet addresses for the tokens you mentioned:

• USDC: 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48
• DAI: 0x6B175474E89094C44Da98b954EedeAC495271d0F

[lucashenning]

Hi @thegostep,

Sorry I forgot to mention I'm using ropsten. The swap works in the uniswap UI (on ropsten with the addresses that I posted).

[thegostep]

@lucashenning

ah - there is no uniswap pair contract deployed for USDC-DAI on ropsten

you can see here: https://ropsten.etherscan.io/address/0x5C69bEe701ef814a2B6a3EDD4B1652CB9cc5aA6f#readContract

you will need to deploy the pair and add liquidity for the the system to work

lmk if you have any other qs

[lucashenning]

Hm, interesting... I see what you mean, getPair() returns 0x00000...

The two addresses that I posted do work in the UI, though. Here's a successful ropsten tx using those addresses: https://ropsten.etherscan.io/tx/0xb77126b28ca32855f467a086b54818c35fa21859dad8b7a33a49dcdd2dd540d4

I'm using these addresses (works in the UI but not in the code):

const uniSwapRouterAddress = '0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D'; 
const USDC = '0x0D9C8723B343A8368BebE0B5E89273fF8D712e3C'; // USDC Address
const DAI = '0xad6d458402f60fd3bd25163575031acdce07538d';

I must be missing something. Any ideas?

[thegostep]

The package does not currently support routing through a third token

[lucashenning]

Thank you! That makes a ton of sense!

Any plans on adding this feature?

[thegostep]

definitely - the hold up is that there is no easy way to calculate routes, it requires some kind of path finding algo using the liquidity in each pool - lots of calls!

[sentiasa]

@thegostep can you please explain your idea on the path finding algo? Why did you say "using liquidity in each pool" instead of just getting the price?