1 files changed, 26 insertions, 0 deletions
diff --git a/lib/gitlab/template_parser/eval_state.rb b/lib/gitlab/template_parser/eval_state.rb
new file mode 100644
index 00000000000..7cf2ab21f50
--- /dev/null
+++ b/lib/gitlab/template_parser/eval_state.rb
@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module TemplateParser
+    # A class for tracking state when evaluating a template
+    class EvalState
+      MAX_LOOPS = 4
+
+      def initialize
+        @loops = 0
+      end
+
+      def enter_loop
+        if @loops == MAX_LOOPS
+          raise Error, "You can only nest up to #{MAX_LOOPS} loops"
+        end
+
+        @loops += 1
+        retval = yield
+        @loops -= 1
+
+        retval
+      end
+    end
+  end
+end