Possible to support object keys?

Would it be possible to support objects as keys rather than forcing everything to be a string?

In my case I’m looking to do something like

const { data } = useSwr(userDetail.prepare({ id: 5 }));

which returns the same object given the same inputs. The object itself has a method on it that is called by the fetcher:

function fetcher(preparedAction) {
    return preparedAction.call();
}

As it is this doesn’t work because the object returned is forced to a string here: https://github.com/zeit/swr/blob/master/src/use-swr.ts#L66

Given the cache is a Map using an object as a key works, eg. changing that line to the following appears to do what I want:

else if (!key || typeof key !== 'object') {
        // convert null to ''
        key = String(key || '');
}

Wrapping it in an array does also work:

const { data } = useSwr([userDetail.prepare({ id: 5 })]);

but the ergonomics aren’t as good (especially given if you forget to wrap it in an array it just doesn’t work - no errors).

Unfortunately other things assume it’s a string as well - eg. CONCURRENT_PROMISES etc are just plain objects rather than a Map.

Is this something that you would be willing to extend the API to accomodate?

My alternative to make this work within the current API constraints would be to have prepare return a string that fetcher can look up into my own global cache… but I was thinking it would be nice to avoid this if swr already did that internally.

[Svish]

For simple cases, you could do something along the lines of what I did for Axios here: https://github.com/zeit/swr/tree/master/examples/axios

It basically just wraps useSWR in a new hook which uses JSON.stringify to create a key for the request object. Works fine so far here at least 🙂

[shuding]

Update: I’m planning to add key serialization and object key support in #1429.