Add lemmy v0.19 authentication support

[aeharding]

NOTE: This just fixes auth for lemmy v0.19.

One month after lemmy v0.19 is released, a new version of Voyager will be released that phases out support for v0.18.

This will allow Voyager to adopt new v0.19 features.

NOTE 2: A new, breaking change of Voyager (Voyager v2) will likely be released sooner than that. Since the native clients can send a custom Cookie header, we can upgrade lemmy-js-client sooner than that. The web version will remain stuck of Voyager v1 until most Lemmy servers have a chance to upgrade to v0.19 (one month after v0.19 release)

NOTE3: Phase 2 PR is coming soon.

[phiresky]

Hey. quick question about this. even with 0.19 you still get the jwt token in the login body json response.

And you don't need to set a cookie header, you can also set a Authorization: `Bearer ${jwt}` header, which should work fine with the fetch api (https://stackoverflow.com/a/48943220/2639190 ). Did you consider this when saying you need to break backwards compat?

edit: i see you're using that header. maybe you need to add withCredentials: true, credentials: 'include', as seen in the above answer? or I'm missing something.

[aeharding]

Lemmy 0.18 doesn’t support the authorization header afaik. Only the cookie header (or auth url parameter)

[phiresky]

yes but you can still send both right? should be independent of other new features. I mean make sense to drop support at some point just wondering about your reasoning and if there's any incompatibility on Lemmy s side

[aeharding]

Yes, I can send both - However, lemmy-js-client v0.19 removes support for auth URL param. Which means that the only way to authenticate with lemmy v0.18 using lemmy-js-client v0.19 is to use the cookie header (which is incompatible with web-based clients)

That's why this PR keeps lemmy-js-client v0.18 - as a stopgap to allow compatibility with lemmy v0.18 and v0.19 for web-based clients. The only downside is since lemmy-js-client is stuck on v0.18, I can't take advantage of any new v0.19 features.