source: frontend/node_modules/stop-iteration-iterator/index.js

'use strict';

var SLOT = require('internal-slot');
var $SyntaxError = require('es-errors/syntax');

var $StopIteration = typeof StopIteration === 'object' ? StopIteration : null;

/** @type {import('.')} */
module.exports = function getStopIterationIterator(origIterator) {
        if (!$StopIteration) {
                throw new $SyntaxError('this environment lacks StopIteration');
        }

        SLOT.set(origIterator, '[[Done]]', false);

        /** @template T @typedef {T extends Iterator<infer U> ? U : never} IteratorType */
        /** @typedef {IteratorType<ReturnType<typeof getStopIterationIterator>>} T */
        var siIterator = {
                next: /** @type {() => IteratorResult<T>} */ function next() {
                        // eslint-disable-next-line no-extra-parens
                        var iterator = /** @type {typeof origIterator} */ (SLOT.get(this, '[[Iterator]]'));
                        var done = !!SLOT.get(iterator, '[[Done]]');
                        try {
                                return {
                                        done: done,
                                        // eslint-disable-next-line no-extra-parens
                                        value: done ? void undefined : /** @type {T} */ (iterator.next())
                                };
                        } catch (e) {
                                SLOT.set(iterator, '[[Done]]', true);
                                if (e !== $StopIteration) {
                                        throw e;
                                }
                                return {
                                        done: true,
                                        value: void undefined
                                };
                        }
                }
        };

        SLOT.set(siIterator, '[[Iterator]]', origIterator);

        // @ts-expect-error TODO FIXME
        return siIterator;
};