Passing argument of trigger to optimisticData function.

[pociej]

Correct me if im wrong but optimisticData is function of one argument, current data. This end up with awkward usage as in documentation :

import useSWRMutation from 'swr/mutation'

function Profile () {
  const { trigger } = useSWRMutation('/api/user', updateUserName)

  return (
    <div>
      <h1>My name is {data.name}.</h1>
      <button onClick={async () => {
        const newName = data.name.toUpperCase()

        trigger(newName, {
          optimisticData: user => ({ ...user, name: newName }),
          rollbackOnError: true
        })
      }}>Uppercase my name!</button>
    </div>
  )
}

I would prefer not be forced to set config like this in button onClick handler. Instead I would like

to do it that way

import useSWRMutation from 'swr/mutation'

function Profile () {
  const { trigger } = useSWRMutation('/api/user', updateUserName , {
    optimisticData : (currentData, newName) =>  ({ ...user, name: newName }),
  })

  return (
    <div>
      <h1>My name is {data.name}.</h1>
      <button onClick={async () => {
        const newName = data.name.toUpperCase()
        trigger(newName)
      }}>Uppercase my name!</button>
    </div>
  )
}

Which doesn't work because argument passed in trigger is not passed down to optimisticData function. Isnt it worth to update api to work like this?

[leonelpena]

Same here. I think it will improve code legibility.