How to Fix Jest Mock for React-Select or React Testing Library onChange Not Firing on Target Change Issue

Introduction: Are you currently facing an issue with Jest mock for React-Select or React Testing Library where the onChange event is not firing correctly on target change? You’re not alone! In this article, we will explore this problem and provide you with a solution to fix it. We’ll dive into the code, discuss possible reasons for the issue, and guide you step-by-step on how to resolve it. So, let’s get started and find out why the change event is only firing once and how we can make it work as expected.

Table of Contents:

1. Understanding the Problem
2. Exploring the Jest Mock
3. Debugging the Issue
4. Solution: Modifying the fireEvent.change
5. Testing the Updated Code
6. Additional Tips and Considerations
7. Conclusion
8. Understanding the Problem: Before we delve into the solution, let’s first understand the problem at hand. You mentioned that no matter what you do, the fireEvent.change from React Testing Library only fires on the first call. This means that when you try to simulate a change event using fireEvent.change on a React-Select component, it works fine for the first call but fails to trigger subsequent onChange events. This can be frustrating and prevent you from testing your code properly.
9. Exploring the Jest Mock: To address this issue, let’s take a closer look at the Jest mock code you provided. The mock is used to replace the original React-Select component during testing. It overrides the behavior of the select element, intercepts the onChange event, and triggers the provided onChange function when an option is selected. The code seems straightforward and should work as expected.
10. Debugging the Issue: To debug the problem, you mentioned that you used console.log to check if the handleChange function is being called multiple times. Surprisingly, you noticed that it is only called once, even when you fire multiple change events on different select elements. This indicates that the issue lies within the fireEvent.change itself, rather than the Jest mock implementation.
11. Solution: Modifying the fireEvent.change: To fix the problem, we need to modify the way we use fireEvent.change in our tests. Currently, you are using queryAllByTestId to get the select elements and then firing change events on them separately. However, this approach might not work as expected due to React’s internal rendering and update mechanisms. Instead, we can modify our approach to ensure that the select elements are queried after each change event, avoiding any potential conflicts.

Here’s an updated version of your test code:

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const { queryByTestId } = renderWithRedux(
  <TabByRestraints setOpen={mockSetOpen} hidden={false} />,
  {
    userCatagories: userCategoriesMock,
    permissionGroups: permissionGroupsMock,
    roles: rolesMock
  }
);

// Query for the select elements after each change event
const firstSelect = queryByTestId("select1");
fireEvent.change(firstSelect, { target: { value: "0" } });

const secondSelect = queryByTestId("select2");
fireEvent.change(secondSelect, { target: { value: "132" } });

// Assert the expected behavior
expect(getByLabelText("Add a new user category restraint")).toBeTruthy();

By querying the select elements after each fireEvent.change call, we ensure that the correct elements are targeted and that the onChange events are triggered as expected.

5. Testing the Updated Code: Once you’ve made the modifications, run your tests again to check if the issue has been resolved. You should now see that the onChange events are firing correctly for both select elements, allowing your test to pass successfully.
6. Additional Tips and Considerations:

• Make sure that the option with value 132 exists in the second select element at the time the fireEvent.change is executed. You can use the debug function provided by React Testing Library to verify the rendered options.
• If you encounter any other issues related to testing React-Select components, consider referring to the official documentation and community resources for further guidance.

7. Conclusion: In this article, we discussed the problem of the onChange event not firing correctly when using Jest mock for React-Select or React Testing Library. We explored the code, identified the issue with fireEvent.change, and provided a solution to fix the problem. By modifying the way we query and fire change events on the select elements, we ensure that the onChange events are triggered as expected. Remember to adapt these changes to your specific codebase and continue testing to ensure the desired functionality.