Pre-request Scripts in Postman

Syntax

Pre-request scripts in Postman are written in JavaScript and must be enclosed in the pm.sendRequest() function.

Example

Here's an example of a pre-request script in Postman:

pm.sendRequest('https://api.example.com/token', function (err, res) {
    pm.environment.set('token', res.json().token);
});

Output

The output of a pre-request script will vary depending on the specific actions being performed. In the example above, the output will be a token that is stored in the Postman environment.

Explanation

Pre-request scripts in Postman are JavaScript functions that are executed before a request is sent. These scripts are used to set variables, modify the request, or perform other actions that are required prior to sending the request. This can be useful for scenarios where authentication tokens or other variables need to be set dynamically.

Use

Pre-request scripts are commonly used in Postman to set environment variables, headers, or authentication tokens before sending a request. By using pre-request scripts, you can automate the process of setting these variables and ensure that they are always up-to-date.

Important Points

• Pre-request scripts in Postman are written in JavaScript.
• Pre-request scripts are executed before a request is sent.
• Pre-request scripts can be used to modify the request, set variables, or perform other actions required prior to sending the request.

Summary

Pre-request scripts in Postman are a useful tool for setting variables, modifying requests, and automating certain actions that are required prior to sending a request. By using pre-request scripts, you can streamline your Postman workflow and make testing APIs more efficient.