1 files changed, 61 insertions, 0 deletions
diff --git a/activesupport/test/core_ext/module/attribute_aliasing_test.rb b/activesupport/test/core_ext/module/attribute_aliasing_test.rb
new file mode 100644
index 0000000000..81aac224f9
--- /dev/null
+++ b/activesupport/test/core_ext/module/attribute_aliasing_test.rb
@@ -0,0 +1,61 @@
+# frozen_string_literal: true
+
+require "abstract_unit"
+require "active_support/core_ext/module/aliasing"
+
+module AttributeAliasing
+  class Content
+    attr_accessor :title, :Data
+
+    def initialize
+      @title, @Data = nil, nil
+    end
+
+    def title?
+      !title.nil?
+    end
+
+    def Data?
+      !self.Data.nil?
+    end
+  end
+
+  class Email < Content
+    alias_attribute :subject, :title
+    alias_attribute :body, :Data
+  end
+end
+
+class AttributeAliasingTest < ActiveSupport::TestCase
+  def test_attribute_alias
+    e = AttributeAliasing::Email.new
+
+    assert_not_predicate e, :subject?
+
+    e.title = "Upgrade computer"
+    assert_equal "Upgrade computer", e.subject
+    assert_predicate e, :subject?
+
+    e.subject = "We got a long way to go"
+    assert_equal "We got a long way to go", e.title
+    assert_predicate e, :title?
+  end
+
+  def test_aliasing_to_uppercase_attributes
+    # Although it's very un-Ruby, some people's AR-mapped tables have
+    # upper-case attributes, and when people want to alias those names
+    # to more sensible ones, everything goes *foof*.
+    e = AttributeAliasing::Email.new
+
+    assert_not_predicate e, :body?
+    assert_not_predicate e, :Data?
+
+    e.body = "No, really, this is not a joke."
+    assert_equal "No, really, this is not a joke.", e.Data
+    assert_predicate e, :Data?
+
+    e.Data = "Uppercased methods are the suck"
+    assert_equal "Uppercased methods are the suck", e.body
+    assert_predicate e, :body?
+  end
+end