busboy.js

  const busboy = require('co-busboy')
  
  const parts = busboy(ctx, {
      limits: {
        fieldSize: 10 * 1024 * 1024,
      },
    })

    let part
    
    while (part = await parts) {
      switch (part[0]) {
        case 'message': {
          body.message = part[1]
          break
        }
        case 'files': {
          body.files.push(await obj.run(part[1]))
          break
        }
        default:
          break
      }
    }