612-kebabcase.ts

/*
  612 - KebabCase
  -------
  by Johnson Chu (@johnsoncodehk) #medium #template-literal

  ### Question

  Replace the `camelCase` or `PascalCase` string with `kebab-case`.

  `FooBarBaz` -> `foo-bar-baz`

  For example

  ```ts
  type FooBarBaz = KebabCase<"FooBarBaz">;
  const foobarbaz: FooBarBaz = "foo-bar-baz";

  type DoNothing = KebabCase<"do-nothing">;
  const doNothing: DoNothing = "do-nothing";
  ```

  > View on GitHub: https://tsch.js.org/612
*/

/* _____________ Your Code Here _____________ */

type KebabCase<S extends string> = S extends `${infer F}${infer R}`
    ? R extends Uncapitalize<R> ? `${Uncapitalize<F>}${KebabCase<R>}` : `${Uncapitalize<F>}-${KebabCase<R>}`
    : S;

/* _____________ Test Cases _____________ */
import type { Equal, Expect } from '@type-challenges/utils'

type cases = [
    Expect<Equal<KebabCase<'FooBarBaz'>, 'foo-bar-baz'>>,
    Expect<Equal<KebabCase<'fooBarBaz'>, 'foo-bar-baz'>>,
    Expect<Equal<KebabCase<'foo-bar'>, 'foo-bar'>>,
    Expect<Equal<KebabCase<'foo_bar'>, 'foo_bar'>>,
    Expect<Equal<KebabCase<'Foo-Bar'>, 'foo--bar'>>,
    Expect<Equal<KebabCase<'ABC'>, 'a-b-c'>>,
    Expect<Equal<KebabCase<'-'>, '-'>>,
    Expect<Equal<KebabCase<''>, ''>>,
    Expect<Equal<KebabCase<'😎'>, '😎'>>,
]

/* _____________ Further Steps _____________ */
/*
  > Share your solutions: https://tsch.js.org/612/answer
  > View solutions: https://tsch.js.org/612/solutions
  > More Challenges: https://tsch.js.org
*/