Monitor network request URL and response content (Throw custom exceptions)

Question

How can network requests be monitored and evaluated for their request URL, parameters, request, and response data?

Desired solution

I want to be notified or being given a custom exception, if specific content occurs in request or response.

Example

Assume a web application with many dynamic Ajax requests. A request or response might contain a broken value, e.g. undefined.

Request URL:

http://localhost:8080/app/?undefined=1

Response JSON data:

{"undefined":"1"}

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Attempts

• Filtering for request content in Dev Tools is not possible
• PostMan tests seem not viable (e.g. no user interactions)

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Not tried/found yet

Guesses of what might work ...

• Software to intercepts requests and log/alert details
• Proxying any URLs on an OS via some standalone application

Answer 1

If importing axios, you could leverage custom interceptors:

// Add a response interceptor
axios.interceptors.response.use(function (response) {
    // Any status code that lie within the range of 2xx cause this function to trigger
    // Do something with response data
    return response;
  }, function (error) {
    // Any status codes that falls outside the range of 2xx cause this function to trigger
    // Do something with response error
    return Promise.reject(error);
  });


// Similar functionality can be achieved for request
axios.interceptors.request.use(function (config) {
    // Do something before request is sent
    return config;
  }, function (error) {
    // Do something with request error
    return Promise.reject(error);
  });