Should unwrap be avoided and how to chain mutations

[asher-feil]

I've used unwrap in some cases where I have multiple mutations and I want to kick one off after the first one finishes. unwrap allowing me to use Promise.then. I was looking at the docs, when I see unwrap mentioned it also says

This can be useful if you wish to determine whether the mutation succeeds/fails inline at the call-site.

Which has me wondering if unwrap is not meant for the case that I'm using it for and if thats true then what would be the "preferred" method of chaining mutations.

[EskiMojo14]

myMutation(arg).then((res) => {
  if (res.data) {
    // success
  } else {
    res.error
    // failure
  }
})

myMutation(arg).unwrap()
  .then((data) => {
    // success
  }).catch((error) => {
    // failure
  })

They're just two different ways of handling the result of the mutation - both promises will settle when the mutation finishes.

[markerikson]

Dispatching a mutation does return a promise. If all you care about is "did it finish", you can just await dispatch(someMutation()). However, that promise will still resolve successfully even if the actual mutation errored:

• https://redux-toolkit.js.org/api/createAsyncThunk#handling-thunk-results

so if you do care "did this mutation actually succeed", then yes, you'd want to await dispatch(someMutation()).unwrap().

As for waiting for the promise for chaining / sequencing purposes: yes, that's why async thunks return a promise to begin with.