Fiddler Everywhere provides a Rules tab tool, which is a powerful feature that enables you to mock server responses and simulate various real-life scenarios.
You can use the Rule Builder to create rules and automatically trigger a specific request, which meets the criteria set in the rule. To mock a server response, enable the Rules tab, set a rule, and execute the request that will trigger that rule.
To create and test a rule:
- Select the Rules tab and click the Add New Rule button. As a result, the Rule Builder will be opened.
- Enter a descriptive rule name, which will later appear in the Rules Queue.
- Add a condition or a set of conditions to match sessions.
- Add an action or a set of actions to modify the matched sessions.
- Click Save to save and add the created rule in the Rules Queue.
Switch the Live traffic to the Capturing mode.
- If you test with Live Traffic, make sure that you enable the toggle of the main Rules. Open the application in the browser and execute a request that matches the set conditions. The rule is immediately applied to the ongoing captured traffic.
- If you test with saved sessions, select the rule and use the Execute button. The rule is immediately applied to the loaded saved sessions.