typesafe onMutation promise

[quant-daddy]

onMutation hook resolves with the mutation response or reject with any error (except when an onError callback is specified, in which case it will resolve with no value on errors).

Wouldn't it be a good idea to make the resolve value optional regardless of whether onError is specified or nor? Currently, if I specify onError, I still get the typescript type of resolve value as non-null and this could lead to runtime error.

[morrys]

Hi @skk2142, I would like to add this issue to the new release (4.0.0).

The solution that could be adopted is to change this: https://github.com/relay-tools/react-relay-mutation/blob/master/src/index.tsx#L90-L95

if (mergedConfig.onError) {
  mergedConfig.onError(error);
  resolve();
} else {
  reject(error);
}

in

if (mergedConfig.onError) {
  mergedConfig.onError(error);
  resolve(null);
} else {
  reject(error);
}

or

if (mergedConfig.onError) {
  mergedConfig.onError(error);
} 
reject(error);

and remove support for HOC Mutation.

[morrys]

Issue resolved with relay-hooks version 4.0.0