Promise.all

Requirements

• Export promiseAll as the default export. Accept any iterable, including arrays, sets, strings, and generators.
• Return a new promise that fulfills with an array of fulfilled values in the original iteration order, regardless of completion order.
• Reject with the first observed rejection reason without waiting for other pending inputs. Preserve the original rejection reason.
• Treat non-promise values as fulfilled values. Adopt thenables using their eventual outcome, and count each input only once.
• Fulfill an empty iterable with an empty array. Sparse array slots behave as undefined values.
• Invalid iterables or failures while reading/advancing the iterator must reject the returned promise rather than throw synchronously.
• Do not mutate the iterable, its entries, or resolved objects. Do not use Promise.all, Promise.allSettled, Promise.any, or Promise.race in your implementation. Promise.resolve is allowed.
• Implement ordinary Promise behavior only; subclass constructors, custom Promise constructors, cancellation, and cyclic inputs are outside the scope of this exercise.

Examples

Input: await promiseAll([Promise.resolve(1), 2, Promise.resolve(3)])
Output: [1, 2, 3]

Input: await promiseAll([])
Output: []

Input: await promiseAll([Promise.resolve("ready"), Promise.reject("failed")])
Output: Rejects with "failed".

Input: await promiseAll(new Set(["first", Promise.resolve("second")]))
Output: ["first", "second"]