From a70e59463f743830f64f743f8b6c081794b4eaaf Mon Sep 17 00:00:00 2001
From: Clombrong <cromblong@egregore.fun>
Date: Sun, 29 Jun 2025 20:51:22 +0200
Subject: refactor(stream): migrate indifferent features to own function

---
 lib/stream.ml | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/lib/stream.ml b/lib/stream.ml
index cbc8a16..451f9b5 100644
--- a/lib/stream.ml
+++ b/lib/stream.ml
@@ -89,13 +89,16 @@ let negotiate feature portal {starttls; sasl; _} : unit Lwt.t =
          | Error err -> Lwt.fail_with (parse_auth_error err)
          | Ok _ -> print_endline "Success!"; Lwt.return_unit
     else Lwt.fail InsufficientEncryption
-  in let open Feature in
-     match feature with
-     | Mandatory STARTTLS -> Starttls.upgrade portal
-     | Optional STARTTLS -> if starttls.prefer_starttls
-                            then Starttls.upgrade portal
-                            else Lwt.return_unit
-     | f ->
-        match unwrap f with
-        | Mechanisms mechs -> authenticate mechs
-        | _ ->  Lwt.return_unit
+  in
+  let open Feature in
+  (* Most features don't care about whether they're mandatory or optional. *)
+  let indifferent = function
+    | Mechanisms mechs -> authenticate mechs
+    | _ ->  Lwt.return_unit
+  in
+  match feature with
+  | Mandatory STARTTLS -> Starttls.upgrade portal
+  | Optional STARTTLS -> if starttls.prefer_starttls
+                         then Starttls.upgrade portal
+                         else Lwt.return_unit
+  | f ->  unwrap f |> indifferent
-- 
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