import asyncBusboy from 'async-busboy';

// Koa 2 middleware
async function someFunction(ctx, next) {
  const { files, fields } = await asyncBusboy(ctx.req);

  // Make some validation on the fields before upload to S3
  if (checkFiles(fields)) {
    files.map(uploadFilesToS3);
  } else {
    return 'error';
  }
}

import asyncBusboy from 'async-busboy';

// Koa 2 middleware
async function someFunction(ctx, next) {
  const { fields } = await asyncBusboy(ctx.req, {
    onFile: function (fieldname, file, filename, encoding, mimetype) {
      uploadFilesToS3(file);
    },
  });

  // Do validation, but files are already uploading...
  if (!checkFiles(fields)) {
    return 'error';
  }
}

var asyncBusboy = require('async-busboy');

function someFunction(someHTTPRequest) {
  asyncBusboy(someHTTPRequest).then(function (formData) {
    // do something with formData.files
    // do someting with formData.fields
  });
}

// Given an object that represent the form data:
{
  field1: 'value',
  objectField: {
    key: 'anotherValue',
  },
  arrayField: ['a', 'b'],
  //...
}

// -> field1[value]
// -> objectField[key][anotherKey]
// -> arrayField[0]['a']
// -> arrayField[1]['b']
// .....

const serializeFormData = (obj, formDataObj, namespace = null) => {
  var formDataObj = formDataObj || {};
  var formKey;
  for (var property in obj) {
    if (obj.hasOwnProperty(property)) {
      if (namespace) {
        formKey = namespace + '[' + property + ']';
      } else {
        formKey = property;
      }

      var value = obj[property];
      if (
        typeof value === 'object' &&
        !(value instanceof File) &&
        !(value instanceof Date)
      ) {
        serializeFormData(value, formDataObj, formKey);
      } else if (value instanceof Date) {
        formDataObj[formKey] = value.toISOString();
      } else {
        formDataObj[formKey] = value;
      }
    }
  }
  return formDataObj;
};

// -->