Request: 由于 BOM 字符，JSON.parse 失败

概括

当正文充满缓冲区时，不会从响应正文中剥离 BOM

最简单的重现示例

    request({
        url: url,
        json: true,
        strictSSL: false,
    }, (error, response, data) => {
        if (error) {
            throw error;
        }

        if (response.statusCode === 200) {
            // data is string instead of json deserialized object 
        }
    })

预期行为

BOM 字符剥离和 json 响应反序列化

当前行为

JSON.parse 失败并返回一个字符串

可能的解决方案

    if (bufferLength) {
      debug('has body', self.uri.href, bufferLength)
      response.body = Buffer.concat(buffers, bufferLength)
      if (self.encoding !== null) {
        response.body = response.body.toString(self.encoding)
      }
      // `buffer` is defined in the parent scope and used in a closure it exists for the life of the Request.
      // This can lead to leaky behavior if the user retains a reference to the request object.
      buffers = []
      bufferLength = 0
    } else if (strings.length) {
      // The UTF8 BOM [0xEF,0xBB,0xBF] is converted to [0xFE,0xFF] in the JS UTC16/UCS2 representation.
      // Strip this value out when the encoding is set to 'utf8', as upstream consumers won't expect it and it breaks JSON.parse().
      if (self.encoding === 'utf8' && strings[0].length > 0 && strings[0][0] === '\uFEFF') {
        strings[0] = strings[0].substring(1)
      }
      response.body = strings.join('')
    }

正如我们所看到的，当使用字符串而不是缓冲区时，BOM 字符被剥离
提取 else if (strings.length) 之外的代码以始终清理响应正文。

语境

从基于 swashbuckle 的公司自定义 swagger 读取 json 响应

您的环境

| 软件| 版本
| ---------------- | -------
| 请求 | 2.83.0
| 节点 | 9.3.0
| npm | 5.5.1
| 操作系统 | 视窗 10