Add httl test

Author: vietqhoang

test/lint/hashes.rb

@@ -236,5 +236,19 @@ def test_hexpire
         assert_in_range(1..4, r.httl("foo", "f1")[0])
       end
     end
+
+    def test_httl
+      target_version "7.4.0" do
+        assert [-2], r.httl("foo", "f1")
+
+        r.hset("foo", "f1", "v2")
+
+        assert [-1], r.httl("foo", "f1")
+
+        r.hexpire("foo", 4, "f1")
+
+        assert_in_range(1..4, r.httl("foo", "f1")[0])
+      end
+    end
   end
 end