Function f

tests/bigints.test.ts:6–15

(input: string | bigint)

describe('BigInts', () => {
  it(`P.bigint.between(1, 10)`, () => {
    const f = (input: string | bigint) =>
      match(input)
        .with(P.bigint.between(0n, 10n), (value) => {
          type t = Expect<Equal<typeof value, bigint>>;
          return 'between 0 and 10';
        })
        .otherwise((value) => {
          type t = Expect<Equal<typeof value, string | bigint>>;
          return 'something else';
        });

    expect(f(5n)).toBe('between 0 and 10');
    expect(f(0n)).toBe('between 0 and 10');