因此，我已经通过创建一个简单的http服务器解决了该问题。

以下是服务器的代码：

const http = require('http');

const body = [];
let text = null;
let path = null;

function createServer(port) {
  return http.createServer()
    .on('request', (req, res) => {
      if (req.method === 'POST' || req.method === 'PUT') {
        path = req.url;
        req.on('data', (chunk) => {
          body.push(chunk);
        }).on('end', () => {
          text = Buffer.concat(body).toString();
          res.end(`${req.method} success`);
        }).on('error', (err) => {
          console.error(err);
        });
      } else if (req.method === 'GET') {
        res.end(JSON.stringify({ path, text }));
      } else if (req.method === 'DELETE') {
        path = null;
        text = null;
        res.end('DELETE success');
      }
    }).on('error', (err) => {
      console.log(`Server error: ${err}`);
    })
    .listen(port, '0.0.0.0');
}

module.exports = (createServer);

服务器接受POST / PUT / DELETE / GET请求，以处理网关的pushAdd（）/ push（）/ delete（）函数来处理度量标准数据，并检查模拟的pushgateway上的push数据。

同样，保存到服务器的request.url和文本数据将被保存并传递到测试程序以进行验证。

以下是测试案例之一（使用Mocha + Chai）：

describe('Check adding custom push count metric', () => {
  it('Check connection: should return - network status: 200, result contains custom count metric string', async () => {
    metricInstance = promMetric.createCustomPushMetric({
      name: 'test_counter',
      help: 'Used to test the pushgateway for custom counter metrics',
      type: 'counter',
      jobName: 'custom-metric-pushgateway-counter',
      groupings: { key: 'test', type: 'customMetric' },
    });
    await promMetric.addPushMetric(metricInstance, 0.879);
    await sleep(500);
    const result = await chai.request(mockPgwServer).get('/');
    expect(result).to.have.status(200);
    const json = JSON.parse(result.text);
    expect(json.path).to.equal('/metrics/job/custom-metric-pushgateway-counter/key/test/type/customMetric');
    expect(json.text).to.match(/# HELP Push_gateway_test_test_counter Used to test the pushgateway for custom counter metrics/);
    expect(json.text).to.match(/# TYPE Push_gateway_test_test_counter counter/);
    expect(json.text).to.match(/Push_gateway_test_test_counter 0.879/);
  });
});

从客户端发布度量标准时，存储在服务器中的“路径”和“文本”在查询和验证后会发送回客户端。