[Node.js] TmpFile class

index.ts

// src/index.ts

async function main() {
  const tmpFile = new TmpFile();

  const data = { name: "foo", age: 30 };

  await tmpFile.write("users/1.json", JSON.stringify(data));

  console.log(await tmpFile.read("users/1.json"));
}

main().catch(console.error);

tmp-file.ts

// src/core/tmp-file.ts

import { readFile, writeFile, mkdir } from "fs/promises";
import { resolve, dirname } from "path";

// Suppose having `tmp` dir on the project root.
export class TmpFile {
  async read(path: string): Promise<string> {
    const fpath = this.getFilePath(path);

    await this.prepare(fpath);

    const buf = await readFile(fpath);
    return buf.toString();
  }

  async write(path: string, data: string): Promise<void> {
    const fpath = this.getFilePath(path);

    await this.prepare(fpath);

    await writeFile(fpath, data);
  }

  private async prepare(path: string) {
    const dirPath = dirname(path);
    console.log(`dirPath=${dirPath}`);
    await mkdir(dirPath, { recursive: true });
  }

  private getFilePath(path: string) {
    return this.getRootPath() + "/" + path;
  }

  private getRootPath() {
    return resolve(__dirname, "../../tmp");
  }
}