Suggestion: Pass through auth_url from oauth_client$auth_params to oauth_flow/req_oauth

[thohan88]

This may just make sense to me, but I think it would be nice if auth_url (and potentially pkce and redirect_uri) could be included in auth_params. This would make oauth_client a self-contained object which is easier to pass around, especially in the context of multiple clients.

Current situation: Currently, when using oauth_client(), auth_url pkce and redirect_uri need to be specified separately in the flow:

github_client <- oauth_client(
  id = "",
  secret = "",
  token_url = "https://github.com/login/oauth/access_token"
)

oauth_flow_auth_code(
  client = github_client,
  auth_url = "https://github.com/login/oauth/authorize",
  redirect_uri = "http://127.0.0.1:1410"
  pkce = FALSE
)

Proposed Change Override arguments specified within auth_params of the oauth_client object, so that the flow can be simplified:

github_client <- oauth_client(
  id = "",
  secret = "",
  token_url = "https://github.com/login/oauth/access_token",
  auth_params = list(
    auth_url = "https://github.com/login/oauth/authorize",
    redirect_uri = "http://localhost:1410",
    pkce = FALSE
  )
)

oauth_flow_auth_code(client = github_client)

Caveats The above example would of course break if you attempt a device flow:

oauth_flow_device_code(client = github_client)

Which could be overriden with:

oauth_flow_device_code(client = github_client, auth_url = "https://github.com/login/device/code")

Alternatively, one could have auth_url_auth_code and auth_url_device_code, but this feels more clunky. I think most users will rarely mix auth code and device code flows, but not sure here.

Context I'm working on a PR draft for Shiny integration that supports multiple providers. During this process, I found it cleaner and more intuitive to provide a list of oauth_clients rather than managing parameters separately for each client. Fully understand there may be good reasons they are separate today.