1 files changed, 23 insertions, 0 deletions
diff --git a/railties/test/abstract_unit.rb b/railties/test/abstract_unit.rb
index 9ccc286b4e..b6533a5fb2 100644
--- a/railties/test/abstract_unit.rb
+++ b/railties/test/abstract_unit.rb
@@ -26,3 +26,26 @@ end
 def jruby_skip(message = '')
   skip message if defined?(JRUBY_VERSION)
 end
+
+class ActiveSupport::TestCase
+  private
+
+  unless defined?(:capture)
+    def capture(stream)
+      stream = stream.to_s
+      captured_stream = Tempfile.new(stream)
+      stream_io = eval("$#{stream}")
+      origin_stream = stream_io.dup
+      stream_io.reopen(captured_stream)
+
+      yield
+
+      stream_io.rewind
+      return captured_stream.read
+    ensure
+      captured_stream.close
+      captured_stream.unlink
+      stream_io.reopen(origin_stream)
+    end
+  end
+end