Support limit of redirects about bent

[swftvsn]

I'd mirror the fetch spec here and support the three modes also in nodejs:

A request has an associated redirect mode, which is "follow", "error", or "manual". Unless stated otherwise, it is "follow".

"follow"
Follow all redirects incurred when fetching a resource.
"error"
Return a network error when a request is met with a redirect.
"manual"
Retrieves an opaque-redirect filtered response when a request is met with a redirect, to allow a service worker to replay the redirect offline. The response is otherwise indistinguishable from a network error, to not violate atomic HTTP redirect handling.

source: https://fetch.spec.whatwg.org/#requests

It's also specced that:

A redirect status is a status that is 301, 302, 303, 307, or 308.

source: https://fetch.spec.whatwg.org/#statuses

The 20 redirect limit is in the spec:

If request’s redirect count is twenty, return a network error.

source: https://fetch.spec.whatwg.org/#http-redirect-fetch

The browser impl would be just passing that parameter to the fetch, and then tackle the nodejs side with up to 20 redirects. Then it would have full parity.

[mk-pmb]

Looks like following no redirects is actually the default, and I just made a typo in the URL. Could you please clarify the intended redirect behaviour in the Readme then?

[mikeal]

bent doesn’t implement redirect following, although I have considered adding it. But in the browser we use fetch which does its own redirect following, which is why it’s been a bit awkward to figure out how to add this feature to bent in a cross-platform way.

[amio]

I guess we could follow the convention of up to 20 redirects in node side.