Wun Code

TypeScript exam

This exam measures what you've actually learned, in three stages: Easy, Medium, then Hard. Each stage unlocks the next. There are no hints and no ready-made solutions, so it's just you and your code, graded automatically like in the lessons.

  1. Stage 1Locked

    Easy

    • User cardAn interface with an optional field9 min
    • Coffee sizesLiteral types and Record10 min
  2. Stage 2Locked

    Medium

    • A generic groupByA generic function that keeps the type14 min
    • Plucking a fieldThe keyof operator and the field type T[K]14 min
  3. Stage 3Locked

    Hard

    • A todo reducerA discriminated union with every case covered18 min
    • Untrusted dataThe unknown type and a type guard18 min