Implement string escaping

lib/rubrik/document/serialize_object.rb

@@ -22,7 +22,7 @@ def [](obj)
         when PDF::Reader::Reference
           "#{obj.id} #{obj.gen} R"
         when String
-          "(#{obj})"
+          serialize_string(obj)
         when TrueClass
           "true"
         when FalseClass
@@ -48,6 +48,24 @@ def [](obj)
       end
 
       alias call []
+
+      private
+
+      ESCAPE_MAP = {
+        "\n" => "\\\n",
+        "\r" => "\\\r",
+        "\t" => "\\\t",
+        "\b" => "\\\b",
+        "\f" => "\\\f",
+        "\\" => "\\\\",
+        "(" => "\\(",
+        ")" => "\\)"
+      }.freeze
+
+      sig {params(string: String).returns(String)}
+      def serialize_string(string)
+        "(#{string.gsub(/[\n\r\t\b\f\\()]/n, ESCAPE_MAP)})"
+      end
     end
   end
 end

test/rubrik/document/serialize_object_test.rb

@@ -44,11 +44,17 @@ def test_reference_serialization
     end
 
     def test_string_serialization
-      # Act
-      result = SerializeObject["Test"]
-
-      # Assert
-      assert_equal("(Test)", result)
+      # Act + Assert
+      [
+        ["(Test)", "Test"],
+        ["(Test\\))", "Test)"],
+        ["(Test\\\n)", "Test\n"],
+        ["(hello \\\f\\\b hi)", "hello \f\b hi"],
+        ["(This is \\(\\)n inverted backslash \\\\)", "This is ()n inverted backslash \\"],
+        ["(Really \\(\\) \\\r\\\n complicated\\\ttest)", "Really () \r\n complicated\ttest"]
+      ].each do |(expected, subject)|
+        assert_equal(expected, SerializeObject[subject])
+      end
     end
 
     def test_booleans_serialization