For both React and Preact, the useSignal hook implementation is currently defined as:

This implementation would cause the returned signal's .value to only be kept in sync with the value parameter on the very first call.

let param = 0;

// inside a compoenent

const num = useSignal(param); // num.value is 0

// re-render component with a modified param

param = 5;

const num = useSignal(param); // num.value is still 0

One way to get around this behavior is to immediately set the .value on the returned signal:

I am wondering, is there a specific reason that the .value is not set directly in the useSignal function? One possible limitation I can see is that batching multiple signal updates would become not possible.

I do think however that the benefit of synchronizing between a signal's .value and its value parameter outweighs that limitation.