Add test for absolute TTL

Change-Id: I42f9e659692f90f844f42895286f97b31dd1d6a3
Reviewed-on: http://review.couchbase.org/13265
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Reviewed-by: Chris Anderson <jchris@couchbase.com>

test/test_arithmetic.rb

@@ -87,6 +87,17 @@ def test_it_allows_custom_ttl
     refute connection.get(uniq_id(:missing))
   end
 
+  def test_decrement_with_absolute_ttl
+    connection = Couchbase.new(:hostname => @mock.host, :port => @mock.port)
+    # absolute TTL: one second from now
+    exp = Time.now.to_i + 1
+    val = connection.decr(uniq_id, 12, :initial => 0, :ttl => exp)
+    assert_equal 0, val
+    assert_equal 0, connection.get(uniq_id)
+    sleep(2)
+    refute connection.get(uniq_id)
+  end
+
   def test_it_allows_custom_delta
     connection = Couchbase.new(:hostname => @mock.host, :port => @mock.port)