Write pre-request scripts to add dynamic behavior in Insomnia

In this example, we’ll configure a pre-request script that sets a variable in the request:

1. In Insomnia, navigate to the “Flight Service 0.1.0” document.
2. Click the Collections tab.
3. In the sidebar of your collection, select the GET A specific flight by flight number request.
4. Click the Scripts tab on the request.
5. Insomnia provides example pre-request scripts. From the Pre-request tab of Scripts, click Variable Snippets at the bottom of the pane and select Set an environment variable.
6. In the example script, replace variable_name with flightNumber and variable_value with KA0285. The script should look like the following:

   insomnia.environment.set("flightNumber", "KA0285");
   

Now that we created a pre-request script, we can validate it by sending a GET request to the /flights/{flightNumber} endpoint:

1. Click Send. You should get a 200 status code and the following response:

   {
    "number": "KA0285",
    "route_id": "LHR-SFO",
    "scheduled_arrival": "2024-04-03T11:10:00Z",
    "scheduled_departure": "2024-04-03T22:15:00Z"
   }