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Pratik sharma
Pratik sharma Subscriber

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Logging System with Proxy and Fetch

  1. Proxy Object: The fetchLogger wraps the fetch function.
    It uses the apply trap to intercept calls to fetch.

  2. Request Logging:Logs the url and options of the request.
    Response Handling: Logs the response status, status text, and URL.
    Clones the response to ensure the body can be read multiple times.

  3. Error Handling: Captures and logs any errors encountered during the fetch.

  4. Using the Proxy: You can replace fetch globally by assigning the proxy to window.fetch.

// Create a logging wrapper for fetch using Proxy const fetchLogger = new Proxy(fetch, { apply: (target, thisArg, args) => { // Log the request details const [url, options] = args; console.log("Fetch Request:"); console.log("URL:", url); console.log("Options:", options); // Call the original fetch function return Reflect.apply(target, thisArg, args) .then(response => { // Log response details console.log("Fetch Response:"); console.log("Status:", response.status); console.log("Status Text:", response.statusText); console.log("URL:", response.url); // Return the response for further use return response.clone(); // Clone to allow response reuse }) .catch(error => { // Log errors console.error("Fetch Error:", error); throw error; // Rethrow the error for caller handling }); } }); // Example usage of the logging fetch fetchLogger("https://jsonplaceholder.typicode.com/posts", { method: "GET", headers: { "Content-Type": "application/json" } }) .then(response => response.json()) .then(data => console.log("Data:", data)) .catch(error => console.error("Error in fetch:", error)); 
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Replace Global fetch with Logging

window.fetch = fetchLogger; 
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