koa2通过https调用生成小程序码

        app.use(async (ctx, next) => {
         await next()
          ctx.set('content-type', ctx.mimeType)
          ctx.body = ctx.data
        })
        // 获取小程序码
        router.get('/getWxaCode', async (ctx, next) => {
         let page = ctx.request.query.page || '',
         token = ctx.request.header.token || ''
         // 获取小程序码配置
         const codeOptions = {
        method: 'POST',
        url:
        'https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token=' + token,
        body: {
        page: page,
        width: 230,
        scene: 'pc=1',
        },
        json: true,
        encoding: null,
         }
         let imgBuffer = await new Promise(function (resolve, reject) {
         request.post(codeOptions, function (error, response, body) {
        if (!error && response.statusCode == 200) {
        resolve(body)
        }
        reject(error)
        })
         })
          fs.writeFile(page.replace(/\//g, '-') + '.jpg', imgBuffer, function (err) {
        //生成图片(把buffer写入到图片文件)
        if (err) {
        console.log(err)
        }
         })
         // 上传至云存储
         const upOptions = {
        method: 'POST',
        url: 'https://api.weixin.qq.com/tcb/uploadfile?access_token=' + token,
        body: {
        env: env,//小程序云环境的ID
        path: page.replace(/\//g, '-') + '.jpg',
        },
        json: true,
         }
         let res = await new Promise(function (resolve, reject) {
        request(upOptions, function (error, response, body) {
        if (!error && response.statusCode == 200) {
        resolve(body)
        }
        reject(error)
        })
         })
          ctx.data = res
         await next()
        })