A tiny engine for generating file trees

I just tagged 1.0.0 of ts-treegen, a small TypeScript library for describing file structures as data and writing them to disk. If you've ever built a CLI, a scaffolding tool, or anything that needs to generate a bunch of files and folders, you know the usual approach: a pile of fs.writeFileSync calls, manual path joins, and conditional logic scattered everywhere. ts-treegen is my attempt at making that feel less like plumbing and more like just describing what you want. What it looks like import { file , dir , emit , plan } from " ts-treegen/node " ; const files = await emit ( file ( " README.md " , " # My New App " ), dir ( " src " , file ( " index.ts " , " console.log('hello'); " )), ); const p = await plan ( files , { targetDir : " ./output " }); await p . run (); file() and dir() build a tree. emit() resolves it. plan() figures out what needs to be written and gives you a chance to inspect it before anything touches disk. That's the whole API. Conditional files don't need any special syntax either. It's just JavaScript: isProd && file ( " .env.production " , " NODE_ENV=production " ); No template tags, no wrapper nodes to learn. If a value is falsy, it's filtered out. Why I built it this way The goal from the start was to keep the surface area small enough that you could hold the whole API in your head after reading the README once. I went through a few iterations before landing here, and each one was mostly about removing things rather than adding them. Conflict resolution collapsed down to a single overwrite flag. Copy helpers got cut because fs.cp already does the job. Custom error types got replaced with things you'd actually reach for in normal code. Every feature I kept had to earn its place by solving something real, not just being possible to build. Along the way the library also became runtime-agnostic. The core has zero dependencies and works against a small FileSystem interface, so I/O is fully pluggable. ts-treegen/node wires up Node's fs/promises fo