✅ Improve UIDPlusData test coverage

test/net/imap/test_imap_response_parser.rb

@@ -202,4 +202,25 @@ def test_fetch_binary_and_binary_size
     Net::IMAP.debug = debug
   end
 
+  test "COPYUID with backwards ranges" do
+    parser = Net::IMAP::ResponseParser.new
+    response = parser.parse(
+      "A004 OK [copyUID 9999 20:19,500:495 92:97,101:100] Done\r\n"
+    )
+    code = response.data.code
+    assert_equal(
+      {
+         19 =>  92,
+         20 =>  93,
+        495 =>  94,
+        496 =>  95,
+        497 =>  96,
+        498 =>  97,
+        499 => 100,
+        500 => 101,
+      },
+      code.data.uid_mapping
+    )
+  end
+
 end

test/net/imap/test_thread_member.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+require "net/imap"
+require "test/unit"
+
+class ThreadMemberTest < Test::Unit::TestCase
+
+  test "#to_sequence_set" do
+    # copied from the fourth example in RFC5256: (3 6 (4 23)(44 7 96))
+    thmember = Net::IMAP::ThreadMember.method :new
+    thread = thmember.(3, [
+      thmember.(6, [
+        thmember.(4, [
+          thmember.(23, [])
+        ]),
+        thmember.(44, [
+          thmember.(7, [
+            thmember.(96, [])
+          ])
+        ])
+      ])
+    ])
+    expected = Net::IMAP::SequenceSet.new("3:4,6:7,23,44,96")
+    assert_equal(expected, thread.to_sequence_set)
+  end
+
+end

test/net/imap/test_uid_plus_data.rb

@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+require "net/imap"
+require "test/unit"
+
+class TestUIDPlusData < Test::Unit::TestCase
+
+  test "#uid_mapping with sorted source_uids" do
+    uidplus = Net::IMAP::UIDPlusData.new(
+      1, [19, 20, *(495..500)], [*(92..97), 100, 101],
+    )
+    assert_equal(
+      {
+         19 =>  92,
+         20 =>  93,
+        495 =>  94,
+        496 =>  95,
+        497 =>  96,
+        498 =>  97,
+        499 => 100,
+        500 => 101,
+      },
+      uidplus.uid_mapping
+    )
+  end
+
+  test "#uid_mapping for with source_uids in unsorted order" do
+    uidplus = Net::IMAP::UIDPlusData.new(
+      1, [*(495..500), 19, 20], [*(92..97), 100, 101],
+    )
+    assert_equal(
+      {
+        495 =>  92,
+        496 =>  93,
+        497 =>  94,
+        498 =>  95,
+        499 =>  96,
+        500 =>  97,
+         19 => 100,
+         20 => 101,
+      },
+      uidplus.uid_mapping
+    )
+  end
+
+end