1 files changed, 24 insertions, 0 deletions
diff --git a/test/rubygems/test_gem_safe_yaml.rb b/test/rubygems/test_gem_safe_yaml.rb
new file mode 100644
index 0000000000..02df9f97da
--- /dev/null
+++ b/test/rubygems/test_gem_safe_yaml.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+require_relative "helper"
+
+Gem.load_yaml
+
+class TestGemSafeYAML < Gem::TestCase
+  def test_aliases_enabled_by_default
+    assert_predicate Gem::SafeYAML, :aliases_enabled?
+    assert_equal({ "a" => "a", "b" => "a" }, Gem::SafeYAML.safe_load("a: &a a\nb: *a\n"))
+  end
+
+  def test_aliases_disabled
+    aliases_enabled = Gem::SafeYAML.aliases_enabled?
+    Gem::SafeYAML.aliases_enabled = false
+    refute_predicate Gem::SafeYAML, :aliases_enabled?
+    expected_error = defined?(Psych::AliasesNotEnabled) ? Psych::AliasesNotEnabled : Psych::BadAlias
+    assert_raise expected_error do
+      Gem::SafeYAML.safe_load("a: &a\nb: *a\n")
+    end
+  ensure
+    Gem::SafeYAML.aliases_enabled = aliases_enabled
+  end
+end