If a Template in a builtin helper

if a Template in a builtin helper,like:

...
{{with data}}
    {{> templateB}}

{{/with}}
...

if the data is change ,will the templateB rerender?

No it won’t.
However, many things might happen: template sub-parts depending on data will be re-rendered, helpers which reactively depend on data will be called, and maybe some other things I don’t have in mind.

thanks you …