storage-upload/api/media/formidable.mjs

import fs from 'fs'
import { HttpError } from '../error.mjs'
import formidable from 'formidable'
import config from '../config.mjs'

let lastDateString = ''
let incrementor = 1

export function uploadFile(ctx, siteName, noprefix = false) {
  return new Promise((res, rej) => {
    const date = new Date()

    let prefix = ''

    if (!noprefix) {
      // Generate 'YYYYMMDD_HHMMSS_' prefix
      prefix = date
        .toISOString()
        .replace(/-/g, '')
        .replace('T', '_')
        .replace(/:/g, '')
        .replace(/\..+/, '_')

      // Append xx_ if same date is hit multiple times
      if (prefix === lastDateString) {
        prefix += incrementor.toString().padStart('2', '0') + '_'
        incrementor++
      } else {
        lastDateString = prefix
      }
    }

    var form = new formidable.IncomingForm()
    form.uploadDir = `./public/${siteName}`
    form.maxFileSize = config.get('fileSize')

    form.parse(ctx.req, function(err, fields, files) {
      if (err) return rej(err)
      if (!files || !files.file) return rej(new HttpError('File in body was missing', 422))
      let file = files.file

      Object.keys(fields).forEach(function(key) {
        try {
          fields[key] = JSON.parse(fields[key])
        } catch { }
      })
      ctx.req.body = fields

      fs.rename(files.file.path, `./public/${siteName}/${prefix}${file.name}`, function(err) {
        if (err) return rej(err)
        file.path = `./public/${siteName}/${prefix}${file.name}`
        file.filename = `${prefix}${file.name}`

        return res(file)
      })
    })
  })
}