⚙ Compilation target

ESNext

⚙ Library

lib.esnext.d.ts

Missing / Incorrect Definition

global Iterator class

Sample Code

Iterator.from([1, 2, 3, 4, 5])
  .map(n => n + 1)
  .filter(n => n > 2)
  .drop(1)
  .take(2)
  .toArray() // [4, 5]

See also all the validation tests (working since Node.js 22.0.0) at https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helpers

However, the following code should (ideally) continue working:

const customIterator: Iterator<number> = { next: () => ({ value: 42 }) };

Documentation Link

• TC39 Proposal: https://github.com/tc39/proposal-iterator-helpers
• MDN Documentation: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helpers