Improve upgrade docs from V3 -> V4

[dannyheard7]

I am in the process of upgrading the BFF package from V3 to V4. The official migration guide states This upgrade guide covers cases where a breaking change was introduced. However there seems to be a lot of missing breaking changes from this guide that I have come across.

1. Changes to IUserSessionStore

The change from a string key to PartitionKey and UserKey is a breaking change, and there is no documentation about how these new properties relate to the previous string key. This makes it very difficult with a custom session store implementation as we need to know how to migrate existing sessions.

2. Removal of IUserService and DefaultUserService

3. Removal of HttpContext.GetUserAccessTokenAsync extension method

These are the ones I have encountered, however there are likely more. Is there a reason these changes were not documented in the upgrade guide? And could you give advice of how to migrate these to v4 please.

[maartenba]

Good catch! Just went through the upgrade guide and updated it: https://docs.duendesoftware.com/bff/upgrading/bff-v3-to-v4/

Hope this helps clarify the upgrade path a bit more (extensibility of IUserService and friends may need some rework)

[Erwinvandervalk]

fyi, a PR has been raised for this. DuendeSoftware/products#2329

[maartenba]

Docs PR is also ready once we ship the package: DuendeSoftware/docs.duendesoftware.com#994

[dannyheard7]

Great thanks. I've currently gone down the route of a custom user endpoint implementation, but will replace with this once it's released

[maartenba]

Docs are up with the correct way of doing this https://docs.duendesoftware.com/bff/extensibility/management/user/, and a new package has been uploaded.

[maartenba]

(linking https://github.com/orgs/DuendeSoftware/discussions/465)