White noise testing for functional time series

We review white noise tests in the context of functional time series, and compare many them using a custom developed R package wwntests. The are categorized based on whether they conducted domain or spectral domain, valid for i.i.d. general uncorrelated noise. also extend several residual-based goodness-of-fit popular models used data analysis. Through numerous simulation experiments application, we demonstrate use these tests, able to provide practical guidance their implementation, benefits, drawbacks.