Jest worker encountered 4 child process exceptions, exceeding retry limit

When encountering the error message “jest worker encountered 4 child process exceptions, exceeding retry limit,” it means that the Jest test runner has encountered multiple failures in child processes during test execution. Jest spawns child processes to run tests concurrently, and if too many of these processes fail, it exceeds the retry limit set by Jest.

This error typically occurs when there are issues with the code being tested or the environment in which the tests are running. It could be due to a variety of reasons such as unhandled exceptions, memory leaks, or insufficient resources to run the tests.

To resolve this error, you can try the following steps:

1. Check for any unhandled exceptions in your code: Make sure to catch and handle any exceptions properly in your code. Unhandled exceptions can cause the child processes to fail and exceed the retry limit. Fix any issues that may be causing these exceptions.

2. Check for memory leaks: If your tests are leaking memory, it can lead to failures in the child processes. Make sure to clean up any resources or variables that are no longer needed. You can use tools like memory profilers to identify and fix any memory leaks.

3. Increase the retry limit: If the failures in the child processes are intermittent and not due to code or environment issues, you can consider increasing the retry limit in Jest configuration. This allows Jest to make more attempts before considering the test execution as failed. However, it is recommended to fix the underlying issues rather than relying solely on increasing the retry limit.

Example:

      
        describe('Example test suite', () => {
          test('Example test case', () => {
            // Testing code goes here
          });
        });