From 859d74279a41ff7aa1672a02e634120cdfd4c4e7 Mon Sep 17 00:00:00 2001
From: Nobuyoshi Nakada <nobu@ruby-lang.org>
Date: Sat, 12 Jul 2025 15:53:33 +0900
Subject: [PATCH] [ruby/uri] More tests for `check_to`

https://github.com/ruby/uri/commit/b1b5f9a476
---
 test/uri/test_mailto.rb | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/test/uri/test_mailto.rb b/test/uri/test_mailto.rb
index e7c04ef068..31adae2087 100644
--- a/test/uri/test_mailto.rb
+++ b/test/uri/test_mailto.rb
@@ -165,6 +165,45 @@ class URI::TestMailTo < Test::Unit::TestCase
     assert_raise(URI::InvalidComponentError) do
       u.to = 'n.@invalid.email'
     end
+
+    # Invalid host emails
+    assert_raise(URI::InvalidComponentError) do
+      u.to = 'a@.invalid.email'
+    end
+
+    assert_raise(URI::InvalidComponentError) do
+      u.to = 'a@invalid.email.'
+    end
+
+    assert_raise(URI::InvalidComponentError) do
+      u.to = 'a@invalid..email'
+    end
+
+    assert_raise(URI::InvalidComponentError) do
+      u.to = 'a@-invalid.email'
+    end
+
+    assert_raise(URI::InvalidComponentError) do
+      u.to = 'a@invalid-.email'
+    end
+
+    assert_raise(URI::InvalidComponentError) do
+      u.to = 'a@invalid.-email'
+    end
+
+    assert_raise(URI::InvalidComponentError) do
+      u.to = 'a@invalid.email-'
+    end
+
+    u.to = 'a@'+'invalid'.ljust(63, 'd')+'.email'
+    assert_raise(URI::InvalidComponentError) do
+      u.to = 'a@'+'invalid'.ljust(64, 'd')+'.email'
+    end
+
+    u.to = 'a@invalid.'+'email'.rjust(63, 'e')
+    assert_raise(URI::InvalidComponentError) do
+      u.to = 'a@invalid.'+'email'.rjust(64, 'e')
+    end
   end
 
   def test_to_s