图片 url blob base64 互转

待补充

// url to blob
export const urlToBlob = async (url: string) => {
  return new Promise(resolve => {
    fetch(url).then(res => res.blob()).then(blob => {
      resolve(blob)
    })
  })
}

// blob to base64
export const blobToDataURI = (blob: any) => {
  return new Promise(resolve => {
    let reader = new FileReader()
    reader.readAsDataURL(blob)
    reader.onload = (e: any) => {
      resolve(e.target.result)
    }
  })
}