✨ Coerce search args with SequenceSet.try_convert

lib/net/imap.rb

@@ -1948,6 +1948,7 @@ def uid_expunge(uid_set)
     #     * +Set+
     #     * +Range+
     #     * <tt>-1</tt> and +:*+ -- both translate to <tt>*</tt>
+    #     * responds to +#to_sequence_set+
     #     * nested +Array+
     #   * Any +String+ is sent verbatim when it is a valid \IMAP atom,
     #     and encoded as an \IMAP quoted or literal string otherwise.
@@ -3208,7 +3209,7 @@ def coerce_search_arg_to_seqset?(obj)
       when Set, -1, :* then true
       when Range       then true
       when Array       then true
-      else                  false
+      else                  obj.respond_to?(:to_sequence_set)
       end
     end
 

test/net/imap/test_imap.rb

@@ -1230,6 +1230,13 @@ def test_unselect
       imap.search([:*])
       assert_equal "*", server.commands.pop.args
 
+      seqset_coercible = Object.new
+      def seqset_coercible.to_sequence_set
+        Net::IMAP::SequenceSet[1..9]
+      end
+      imap.search([seqset_coercible])
+      assert_equal "1:9", server.commands.pop.args
+
       server.on "UID SEARCH", &search_resp
       assert_equal search_result, imap.uid_search(["subject", "hello",
                                                    [1..22, 30..-1]])