aubade/src/transform/chain.js

filesystem-based content processor

export function chain(items, options) {
    const { breakpoint, key = 'flank', sort, transform = ({ slug, title }) => ({ slug, title }), } = options;
    sort && items.sort(sort);
    for (let idx = 0; idx < items.length; idx++) {
        const [back, next] = [items[idx - 1], items[idx + 1]];
        if (!back && !next)
            continue;
        items[idx][key] = items[idx][key] || {};
        if (back)
            items[idx][key].back = transform(back);
        if (breakpoint && breakpoint(next))
            return items;
        if (next)
            items[idx][key].next = transform(next);
    }
    return items;
}