don't log errors in subroutines

Author: yasunariw

lib/slack.ml

@@ -5,8 +5,6 @@ open Common
 open Github_j
 open Slack_j
 
-let log = Log.from "slack"
-
 let empty_attachments =
   {
     mrkdwn_in = None;
@@ -361,23 +359,19 @@ let generate_commit_comment_notification api_commit notification channel =
   in
   { channel; text = None; attachments = Some [ attachment ]; blocks = None }
 
-let has_valid_signature ?(version = "v0") ?signing_key ~headers body =
+let validate_signature ?(version = "v0") ?signing_key ~headers body =
   match signing_key with
-  | None -> true
+  | None -> Ok ()
   | Some key ->
   match List.Assoc.find headers "x-slack-signature" ~equal:String.equal with
-  | None ->
-    log#error "unable to find header X-Slack-Signature";
-    false
+  | None -> Error "unable to find header X-Slack-Signature"
   | Some signature ->
   match List.Assoc.find headers "x-slack-request-timestamp" ~equal:String.equal with
-  | None ->
-    log#error "unable to find header X-Slack-Request-Timestamp";
-    false
+  | None -> Error "unable to find header X-Slack-Request-Timestamp"
   | Some timestamp ->
     let basestring = Printf.sprintf "%s:%s:%s" version timestamp body in
     let expected_signature = Printf.sprintf "%s=%s" version (Common.sign_string_sha256 ~key ~basestring) in
-    String.equal expected_signature signature
+    if String.equal expected_signature signature then Ok () else Error "signatures don't match"
 
 let has_valid_state ?oauth_state ~args =
   match oauth_state with