Meet ts-collect

Laravel's collections are one of the best APIs in any framework: a fluent, chainable wrapper over arrays that makes data transformation read like a sentence. ts-collect brings that API to TypeScript, with full type inference.

The shape

import { collect } from 'ts-collect'

const topSpenders = collect(orders)
  .filter(order => order.status === 'paid')
  .groupBy('customerId')
  .map(group => ({
    customer: group.first()?.customerName,
    total: group.sum('amount'),
  }))
  .sortByDesc('total')
  .take(5)
  .toArray()

Every step is typed. Rename a property in your model and the chain lights up with errors exactly where it should.

Why not just array methods

You can do all of this with reduce and friends, but groupBy, sum, sortByDesc, chunk, pluck, and a hundred other operations end up hand-rolled in every codebase, slightly differently each time. A collections library standardizes the vocabulary. If you know Laravel, you already know this API; if you do not, the method names say what they do.

ts-collect stays dependency-free and tree-shakeable, and it powers @stacksjs/collections inside the Stacks framework.

Grab it at github.com/stacksjs/ts-collect.