问题：node.js下载图片一直是打开为空的状态

• 错误代码

async getImage(imageUrl) {
    const imageInfo = this.getImageInfo(imageUrl);
    const imagePath = path.join(__dirname, `../static/image/${imageInfo.name}`);
    await request.get(imageUrl).pip(fs.createWriteStream(imagePath))
  },

const rp = = require('request-promise');
async getImage(imageUrl) {
    const imageInfo = this.getImageInfo(imageUrl);
    const imagePath = path.join(__dirname, `../static/image/${imageInfo.name}`);
    await  rp.get(imageUrl).pipe(fs.createWriteStream(imagePath));
  },

• 优化代码

async getImage(imageUrl) {
    const imageInfo = this.getImageInfo(imageUrl);
    const imagePath = path.join(__dirname, `../static/image/${imageInfo.name}`);
    // const isexit = fs.statSync(imagePath);
    return new Promise(resolve => {
      request({
        url: imageUrl,
        encoding:null
      }, (err, response, body) => {
        fs.writeFileSync(
          imagePath, 
          body,
          {
            encoding:'binary'
          }
        )
        resolve()
       })
    })
  },

• 原因：