Is it recommended to test as often as possible when building a complex expression?

Testing as often as possible during the development of complex expressions is indeed a good practice. Frequent testing allows developers to validate the behavior of their expressions incrementally, rather than waiting until the end of the development cycle. By conducting tests throughout the development process, developers can quickly identify and fix issues, reducing the time spent on debugging later.

Regular testing fosters a better understanding of how each part of the expression functions, making it easier to isolate any problems that arise. It also allows for immediate feedback, helping to ensure that the expression behaves as expected at each stage of development. By adopting this approach, developers can maintain confidence in their code, leading to a more robust final result.

In contrast, testing only at the end or only for crucial components can lead to overlooking errors that may compound over time, making them harder to identify and correct. Therefore, continuous testing is a best practice that aligns with agile development principles, aiming for high quality and reliability in the final application.