💥 Validate Set inputs to SequenceSet

Each member of the set should be an integer, a range, or a sequence-set
formatted string.  SequenceSet should not allow Set inputs to be nested.

Author: nevans

lib/net/imap/sequence_set.rb

@@ -37,7 +37,8 @@ class IMAP
     #
     # SequenceSet.new may receive a single optional argument: a non-zero 32 bit
     # unsigned integer, a range, a <tt>sequence-set</tt> formatted string,
-    # another sequence set, or an enumerable containing any of these.
+    # another sequence set, a Set (containing only numbers), or an enumerable
+    # containing any of these (which may be nested).
     #
     #     set = Net::IMAP::SequenceSet.new(1)
     #     set.valid_string  #=> "1"
@@ -1271,6 +1272,7 @@ def input_to_tuples(obj)
         when *STARS, Integer, Range then [input_to_tuple(obj)]
         when String      then str_to_tuples obj
         when SequenceSet then obj.tuples
+        when Set         then obj.map      { to_tuple_int _1 }
         when ENUMABLE    then obj.flat_map { input_to_tuples _1 }
         when nil         then []
         else

test/net/imap/test_sequence_set.rb

@@ -99,6 +99,8 @@ def compare_to_reference_set(nums, set, seqset)
     assert_raise DataFormatError do SequenceSet.new "2 "         end
     assert_raise DataFormatError do SequenceSet.new "2,"         end
     assert_raise DataFormatError do SequenceSet.new Time.now     end
+    assert_raise DataFormatError do SequenceSet.new Set[1, [2]]  end
+    assert_raise DataFormatError do SequenceSet.new Set[1..20]   end
   end
 
   test ".new, input may be empty" do