Refactor Retry

[axdg]

WIP

@elyobo, the below signature is my suggested simplification of the API that we've incremented toward.

fn is wrapped as per the logic given in curve. Curve is expected to be a callback which will be called at each failed iteration with err (the error thrown by the wrapped function) and count which is the count of total attempts to resolve - it should either throw (should no more retries be required) or return an integer dictating the number of milliseconds to sleep before re-attempting resolution.

So, for example, the wrapped function below would retry a maximum of 12 times with exponential (base 2) back off.

const curve = function (err, count) {
  if (count > 12) throw err
  return (2 ** pow) * 1000
}

const wrapped = retry(fn, curve)

We can overload the sig so that it can instead take an object containing options as a second argument, although this wouldn't help much with determining which errors we don't want to retry on (unless the generated function was wrapped again).

What do you think?

[elyobo]

Seems like a cleaner API. It's still possible to opt out of retries, just have your curve throw if you want to stop retrying.

Breaking change.