idea: extract individual contract read errors from useContractReads

[0xVesper]

Is there an existing issue for this?

• I have searched the existing issues

Package Version

0.6.7

Current Behavior

Hello,

I've tried adding an onError to each read of useContractReads, but I don't believe the feature exists.

Is there a way to retrieve the error from each read, instead of aborting and only getting the first error returned?

Thank you 🤝

Expected Behavior

useContractreads only will use onError if allowFailure: false and aborts all of the reads upon a single error. I need the reads to happen for each call passed in, and return an error for each call that happens if it exists.

Steps To Reproduce

For example:

const { data, isError, isLoading } = useContractReads({
    contracts: [
      {
        ...wagmigotchiContract,
        functionName: 'getAlive',
        onError(error) {       // this does nothing since feature doesn't exist
               console.log("Error thrown: ", error);
        },
      },
    ],
  })

It currently forces use of allowFailure, will stop calling the reads after the first error is thrown, and only show said first error:

const { data, isError, isLoading } = useContractReads({
    contracts: [
      {
        ...wagmigotchiContract,
        functionName: 'getAlive'
      },
    allowFailure: false,
    onError(error) {     // only works on first read error and stops all reads
      console.log("Error thrown: ", error);
    },
    ],
  })

Link to Minimal Reproducible Example (CodeSandbox, StackBlitz, etc.)

No response

Anything else?

No response

[jxom]

Thanks for this issue!

Definitely agree it would be nice to have a way to extract the error of a contract read when allowFailure is truthy.

The way onError behaves right now is that it is invoked when the hook's function throws an error, but in this case, it will not as allowFailure is truthy. Perhaps we should have another option to handle this, like onReadError or something.

I'd say this issue is more of a feature request than a bug, so I am going to move this to a discussion under "Ideas" & I'll add it to the wagmi roadmap.

[0xVesper]

The returned error per read shows in the console when allowFailure: true. How can we catch this and use it?

[jxom]

You can't yet, but we can definitely make this happen.

[0xVesper]

I see... it's a necessity in my case since a read is happening per front-end component, so if I don't catch the error I can't display the revert reason for UX.

How could I go about contributing to this feature? Or even a global feature for showing a toast or something whenever any revert happens, inside whatever is handling console.log of the revert..

[iainnash]

Can the return value be the object or an javascript Error object when in this mode?

That way you can iterate the response and handle the Error objects as needed. Multicall3 supports this in the return value.

We recently ran into this with a front-end.

[jxom]

On the roadmap for v1!

[j5h46bd]

Why is allowFailure on reads but not read (singular)? Is there a more appropriate way to suppress a particular common contract reversion?