How to Mock React-Query useQuery in Jest with Moxios

Discover a clear solution to mock `useQuery` from React-Query in your Jest tests, including tips on using Moxios for Axios calls effectively.
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How to Mock React-Query useQuery in Jest with Moxios

If you're working with React and using React Query for data fetching, you might encounter situations where you need to test your components that rely on useQuery. Mocking these queries in your tests can sometimes lead to issues, especially when axios is involved in your data-fetching logic. Let's break down how to effectively mock useQuery while using Jest and Moxios.

The Problem

You're trying to test a function that uses useQuery for fetching data via Axios. The challenge is that simply mocking useQuery directly can lead to complications, such as missing context and state issues. This can make your tests fail or behave unpredictably, leading to frustration.

Code Example

Here's the code structure you're working with:

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

You mentioned trying to use Moxios to mock the Axios calls:

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

However, you faced problems with context and store requirements.

The Solution

To effectively test components that use useQuery, do not mock useQuery itself. Instead, focus on mocking Axios, which can lead to a more robust and reliable test setup.

Step 1: Refactor the Fetch Function

Instead of directly using Axios within fetchWithAxios, pass your Axios instance as a parameter. This way, you can easily inject a mocked version during testing.

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

Step 2: Create a Custom Axios Context

You'll need to create a context to provide the Axios instance throughout your application. This is crucial for testing, as it ensures that your components can access Axios without directly importing it.

Step 3: Write Your Jest Tests

With your code refactored, your Jest tests can now look like this:

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

Key Points to Remember

Do Not Mock useQuery: Instead, mock the Axios calls.

Create Context for Axios: This allows your components to retrieve the Axios instance easily.

Use Moxios Effectively: Stub requests and control responses for testing various scenarios.

Conclusion

Mocking Axios calls when testing React components that use useQuery from React Query can enhance the stability of your tests. By following the outlined steps and refactoring your fetch function to accept an Axios instance, you can create a smoother testing experience. This method not only improves your tests but also aligns with best practices in React development.

Implement these practices in your tests, and you should find that your issues with context and store requirements will be alleviated. Happy coding and testing!