A practical refactoring journey addressing Ruby 3.4's frozen string literal warnings by replacing mutable string concatenation with an immutable array-based approach, then evolving it into a dedicated single-purpose Message class. The solution eliminates primitive obsession, hides implementation details, supports flexible delimiters, and enables clean composition through Ruby's implicit string conversion protocol.
Table of contents
Ruby has both mutable and immutable stringsProblem with string literal mutation in our codeNoticing the patternImprove the codeFinal refactoringSummary480 Impressions