The author critiques common TypeScript validation practices by advocating for Alexis King's 'Parse, Don't Validate' principle, arguing that parsers preserve type information while validators discard it. The article highlights the difficulty of applying this functional programming concept in TypeScript due to its permissive structural typing, which lacks the enforcement found in languages like Haskell or Elm.
Background
The 'Parse, Don't Validate' principle originates from functional programming communities, emphasizing that parsing transforms raw input into precise types, whereas validation merely checks correctness without enriching the type system.
- Source
- Lobsters
- Published
- Jun 30, 2026 at 11:02 PM
- Score
- 6.0 / 10