@studnicky/v8/array-from-iterators

Disallows Array.from(iterable) when the argument is not already an array. Converting iterators (Map, Set, generators) to arrays materializes the full collection in memory — iterate directly instead. When type services are available, the rule uses the TypeScript checker to confirm the argument type.

Fixable: No · Options: No · Suggested severity: error

✗ Incorrect

// Materializes all Map values into an array unnecessarily
const values = Array.from(map.values());

// Materializes all Set entries into an array
const items = Array.from(new Set(source));

✓ Correct

// Iterate directly over the Map values
for (const value of map.values()) {
  process(value);
}

// Spread into array only when the array is truly needed
const snapshot = [...set];