create interactive functions with autocomplete options

[mbristol78]

fish 3.1.2
ubuntu 18.04

Hello,
is there a way to create tab completion within a function?
The complete feature of fish seems to give the ability to have arguments passed to a function, but let say I have a function foo
which, when invoke, can ask the user a choice, like "do_this" or "do_that", available and select-able with the keyboard arrows?
A bit like when you do a "cd" and press tab, you have the list of the folders you can go into.
That would replace a code like
echo "Enter do_this or do_that"; read USER_RESPONSE

with ideally something easy to use like
read_pre-defined_choice' USER_RESPONSE ('do_this do_that')

Which would save the user from typing "do_this" or "do_that"

Thanks

[faho]

There currently is no way to arbitrarily trigger fish's completion pager from script.

That's tracked in #2805, so I'm closing this as a duplicate.