Uncaught (in promise) by calling useSWRMutation trigger function

[peresleguine]

Bug report

Description / Observed Behavior

Uncaught error is thrown inside the fetcher function by triggering useSWRMutation.

Expected Behavior

Error should be caught by SWR and returned as an error object like it happens in useSWR hook.

Repro Steps / Code Example

CodeSandbox

Additional Context

SWR version: 2.0.1

[koba04]

@peresleguine Could you provide a CodeSandbox project to reproduce this?

[peresleguine]

@koba04 changes weren't saved for some reason, sorry: https://codesandbox.io/s/festive-glade-kexfd6?file=/src/App.js

[jdukleth]

Try putting throwOnError to false into the options parameter.

I got this working with the following code. It catches my custom throws fine on bad status codes. I'm throwing an object instead of new Error() though.

[ragnaroks]

i have same problem with SWR@2.1.0, code here:

import useSWRMutation, {SWRMutationResponse} from 'swr/mutation';

type SWRKey = {url:string};

const fetchAsync = async function(key:SWRKey) : Promise<string> {
  let httpResponse:Response;
  let responseData:string;
  try{
    httpResponse = await fetch(key.url,{method:'GET'});
    responseData = await httpResponse.text();
  }catch(exception){
    throw exception as string;
  }
  return responseData;
};

const useData = function() : SWRMutationResponse<string,string,string> {
  const swrKey:SWRKey = {url:'any no reachable URL'};
  return useSWRMutation<string,string,SWRKey,string>(swrKey,fetchAsync);
};

export default useData;

update

my mistake, this is not about SWR, it's other library that replaced fetch

[peresleguine]

So the question is what should be the right default behavior. I guess in terms of throwing errors useSWRMutation should behave like useSWR hook. Probably the throwOnError option should be false by default.

[BryceMehring]

I'm also not seeing an option globally to configure the throwOnError option. The only way to set this option is via the useSWRMutation hook