Server Response Modification

[ ui testing ]

Traffic Analyzers or sniffers allow you to intercept and modify the data that the server sends to the client (e.g., the browser) in response to a request.

The most popular sniffers for testing: Charles and Fiddler.

The browser's built-in DevTools also supports response rewriting:

Modify the server response with DevTools
Test the UI with a modified response

Modifying Server Response with DevTools

DevTools Local Override

DevTools Local Override allows you to locally rewrite the body and headers of the server response.

Open DevTools F12
Go to the Network tab
Refresh the page
Right-click on the request
Click Override content
(Override headers for header changes)
Select a folder to store the modified files
(Select folder)
Click “Allow”
Edit the data
Save changes
Refresh the page

Server Response Manipulation for UI Testing

Changing the server response helps to test UI scenarios in various situations:

When defects occur and the server returns incorrect data
When there is no access to data on the server
When it is difficult to prepare all necessary test data on the server

For example, let's take the profile of a cat named Whiskers.

Requirements

When the page loads, JavaScript sends a request, and the server returns Whiskers' data.

Endpoint /cat-facts
HTTP Method GET
Data format application/json

The response should contain the mandatory field furColor, which can have one of the following values: white, gray, orange, lightsteelblue, rosybrown.

The server response contains an error, please rewrite it using valid furColor values.

Save changes and refresh the page.

Task