server/job-store.js

import { mkdir, readFile, rename, writeFile } from "node:fs/promises";
import path from "node:path";

export class JobStore {
  constructor(rootDir) {
    this.rootDir = rootDir;
  }

  file(id) {
    return path.join(this.rootDir, `${id}.json`);
  }

  async save(job) {
    await mkdir(this.rootDir, { recursive: true });
    const target = this.file(job.id);
    const temporary = `${target}.tmp`;
    await writeFile(temporary, JSON.stringify(job, null, 2), "utf8");
    await rename(temporary, target);
    return job;
  }

  async get(id) {
    return JSON.parse(await readFile(this.file(id), "utf8"));
  }
}