Forward compatible with ERC20 which is`function symbol() view returns (bytes32)`

[hujw77]

• I'm submitting a bug report and feature request When I trade with RING/ETH pair at app.uniswap.org. An HTTP 500 error occur.

  
  ~ curl 'https://api.uniswap.org/v1/quote?protocols=v2%2Cv3&tokenInAddress=0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2&tokenInChainId=1&tokenOutAddress=0x9469D013805bFfB7D3DEBe5E7839237e535ec483&tokenOutChainId=1&amount=11613710000000&type=exactIn' \
      -H 'authority: api.uniswap.org' \
      -H 'pragma: no-cache' \
      -H 'cache-control: no-cache' \
      -H 'accept: */*' \
      -H 'origin: https://app.uniswap.org' \
      -H 'sec-fetch-site: same-site' \
      -H 'sec-fetch-mode: cors' \
      -H 'sec-fetch-dest: empty' \
      -H 'referer: https://app.uniswap.org/' \
      --compressed

{"errorCode":"INTERNAL_ERROR","detail":"Unexpected error","id":"1e381"}

I figure out that is a `smart-order-router` API query, and then I try it by `smart-order-router` CLI.
```shell
~ ./bin/cli quote --tokenIn 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2 --tokenOut 0x9469d013805bffb7d3debe5e7839237e535ec483 --amount 1000 --exactIn --recipient 0xAb5801a7D398351b8bE11C439e05C5B3259aeC9B --protocols v2,v3 --debug
INFO:  [Metric]: TokenListLoad: 1 | Milliseconds
  key: "TokenListLoad"
  value: 1
  unit: "Milliseconds"
INFO:  Found 1 out of 2 tokens in local cache. Checking primary token provider for 1 tokens

  addressesToFindInPrimary: ["0x9469d013805bffb7d3debe5e7839237e535ec483"]
INFO:  Found 0 tokens in primary. Checking secondary token provider for 1 tokens
  addressesToFindInSecondary: ["0x9469d013805bffb7d3debe5e7839237e535ec483"]
DEBUG: About to multicall for symbol across 1 addresses
  calls: [{"target":"0x9469d013805bffb7d3debe5e7839237e535ec483","callData":"0x95d89b41...
DEBUG: About to multicall for decimals across 1 addresses
  calls: [{"target":"0x9469d013805bffb7d3debe5e7839237e535ec483","callData":"0x313ce567...
DEBUG: Results for multicall on decimals across 1 addresses as of block 13900877
  results: [{"success":true,"result":[18]}]
    Error: call revert exception (method="symbol()", errorArgs=null, errorName=null,
    errorSignature=null, reason=null, code=CALL_EXCEPTION, version=abi/5.5.0)
    Code: CALL_EXCEPTION

A call revert error occurred, I think the reason is RING's symbol type is bytes32 not the string. This is a historical reason. https://github.com/dapphub/ds-token/pull/28 And there is a lot of token like MKR have the same issue, but the MKR token is in the @uniswap/default-token-list, so it has no effect on MRK. But other tokens like RING got hit. And I file an issue at https://github.com/Uniswap/default-token-list/issues/1031. To verify my idea, I added RING to @uniswap/default-token-list locally. It works 🚀

~ ./bin/cli quote --tokenIn 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2 --tokenOut 0x9469d013805bffb7d3debe5e7839237e535ec483 --amount 1000 --exactIn --recipient 0xAb5801a7D398351b8bE11C439e05C5B3259aeC9B --protocols v2,v3
Best Route:
[V2] 85.00% = WETH --> RING, [V3] 15.00% = WETH -- 0.3% --> RING
        Raw Quote Exact In:
                16472715.82
        Gas Adjusted Quote In:
                16470330.17

Gas Used Quote Token: 2385.644467
Gas Used USD: 104.133692
Calldata: 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
Value: 0x00

  blockNumber: "13900919"
  estimatedGasUsed: "228000"
  gasPriceWei: "121520560130"

• Summary There are two ways to fix the issue, Add RING token to @uniswap/default-token-list https://github.com/Uniswap/default-token-list/issues/1031 or support ERC20 which isfunction symbol() view returns (bytes32)

[willpote]

Thanks for digging into this and providing such a detailed report!

It would be best to support ERC20 with symbol() view returns (bytes32) but I can't think of an elegant way to do this given the current code (without adding retries).

We generally do not add tokens to the Uniswap default list and prefer users to use community owned lists, so that option is unlikely.

For now, I went with a third option which adds the token to the smart-order-router's hardcoded list of known tokens. We use this list, and the uniswap default token list, to seed our cache of token metadata. https://github.com/Uniswap/smart-order-router/commit/5e60d46c7996eb1a6ee632c65e177cd874dad8db

We will release this to the API in the next few days so RING should be swappable soon

[hujw77]

Thanks for the commit 5e60d46.

It would be best to support ERC20 with symbol() view returns (bytes32) but I can't think of an elegant way to do this given the current code (without adding retries).

I agree with this approach. Because of there is a lot of token still have this issue.