firebaseStorageUpload.js

import firebase from 'firebase/app'
import 'firebase/storage'
import uuid from 'uuid/v4'

export default function upload (file, metadata, onChange) {
  return new Promise((resolve) => {
    const ref = 'media/' + uuid()
    const uploadTask = firebase
      .storage()
      .ref()
      .child(ref)
      .put(file, metadata)

    uploadTask.on(
      'state_changed',
      sp => {
        if (onChange) {
          onChange(sp)
        }
      },
      null,
      () => {
        uploadTask.snapshot.ref.getDownloadURL().then(downloadURL => {
          resolve({
            url: downloadURL,
            id: ref,
            metadata: metadata,
            name: file.name,
            size: file.size,
            uploadedDate: new Date(),
            lastModified: file.lastModified,
            description: ''
          })
        })
      }
    )
  })
}