guard_oauth2.md
In fireproof: Authentication and Authorization for 'fiery' Servers

guard_oauth2 requires auth_url for authorization_code grant

Code
  guard_oauth2(token_url = "https://example.com/oauth/token", redirect_url = "https://myapp.com/auth/callback",
    client_id = "my_client_id", client_secret = "my_client_secret", grant_type = "authorization_code",
    name = "test")
Condition
  Error in `initialize()`:
  ! `auth_url` must be a single string, not `NULL`.

guard_oauth2 reject_response for password grant requests basic auth

Code
  auth$reject_response(no_auth$respond(), scope = NULL, .datastore = datastore)
Condition
  Error in `private$request_password_authorization()`:
  ! Unauthorized