How to Add a Custom Header FOO to Django Rest Framework APIClient

Learn how to customize the Django Rest Framework APIClient to include a custom header `FOO` in your API tests. This guide provides step-by-step instructions for effective unit testing.
---
This video is based on the question https://stackoverflow.com/q/73152530/ asked by the user 'abybaddi009' ( https://stackoverflow.com/u/4055021/ ) and on the answer https://stackoverflow.com/a/73156113/ provided by the user 'abybaddi009' ( https://stackoverflow.com/u/4055021/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Adding a custom header 'FOO' to Django Rest Framework APIClient

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Adding a Custom Header FOO to Django Rest Framework APIClient

When working with Django Rest Framework (DRF), especially in applications using Single Sign-On (SSO), it is not unusual to find the need for custom headers in your API requests. One common requirement could be to add a header like FOO to your requests, aiding in authentication or meeting specific API criteria. However, the default APIClient may not readily support this customization for all applications, leading to potential frustration while writing unit tests. In this post, we'll explore how to effectively add a custom header using Django Rest Framework's testing features.

The Challenge

In a scenario where an application utilizes an AuthBackend for SSO, users are authenticated based on a USERID provided in the headers. While writing unit tests, you might encounter the need to send additional headers along with your requests. Unfortunately, attempts to add custom headers through the default APIClient methods can often lead to unexpected results, as shown here:

[[See Video to Reveal this Text or Code Snippet]]

None of these approaches effectively add the FOO header, leaving our tests unable to function correctly.

The Solution

The solution to this challenge lies in using the RequestsClient provided by Django Rest Framework. This client allows for more flexible configuration of headers, making it easier to simulate requests as they would occur in production.

Step-by-Step Implementation

Import the Required Client:
At the top of your test file, ensure you import the RequestsClient from the DRF test module.

[[See Video to Reveal this Text or Code Snippet]]

Set up Your Test Class:
Replace the APIClient with RequestsClient in your test setup.

[[See Video to Reveal this Text or Code Snippet]]

Add the Required Headers:
In your test method, you can now use the headers.update() method on your client instance to include your custom header.

[[See Video to Reveal this Text or Code Snippet]]

Final Example

Here’s how your complete test case would look:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

Adding a custom header like FOO to your Django Rest Framework APIClient can be crucial for testing authentication and other aspects of your API. By utilizing the RequestsClient, you simplify the process and ensure that your tests can accurately mimic real-world scenarios. This approach not only resolves the limitation of the default APIClient but also enhances your testing capabilities within Django applications.

Remember, testing is an essential part of maintaining robust applications, and leveraging the right tools will help streamline this process.