Feature request: hooks for data fetch about villus

[jbaubree]

Oh, i didn't see then function was provided, this is a solution. Feel free to close this issue if you think onSuccess and onError is too much for this library but i think it's important to have a specific hooks for error and success

[jbaubree]

Update: onFulfilled function in then is only triggered on first call so it does not work with computed variables etc...

[jbaubree]

@logaretm Do you think we can do the same thing for mutations ?

[logaretm]

@jbaubree Usually mutations are executed explicitly, so I don't think it is as common as queries but I don't see the harm. Feel free to PR it, and I guess you ran into needing it recently, would love to hear about it as well, use-case wise.

[jbaubree]

@logaretm There are several reasons why I think it is necessary.
Let's take a simple example:
We are in a login page.

const { execute: signIn } = useMutation<{ signIn: { token: string } }>(SIGN_IN)

async function onSubmit() {
  signIn({ publicAddress, signature }).then(({data, error}) => {
    if (data) <-- Here we don't know if mutation is a success and i find data/error conditions are pains
      //...
    if (error)
      //...
  }
}

Second reason, i find code more readable like this:

const { execute: signIn } = useMutation<{ signIn: { token: string } }>(SIGN_IN, {
  onData(data) {
    setToken(data.signIn.token) <--- We are sure that data exists here
    router.push({ name: 'Root' })
  },
  onError(err) {
    ...
  },
})

async function onSubmit() {
  signIn({ publicAddress, signature })
}

If you confirm that you are ok with that, i will PR it when i will get some free time