Accept inlay type hint and automatically insert into code

[a3lem]

I'm using inlay type hints in a gradually typed Python code base. My language server (basedpyright) is doing a great job of inferring types.

At the moment, whenever I encounter an inlay hint standing in for a missing type hint, I manually edit the code to add the type hint. I was wondering, does there are already exist some way to accept inlay hints? As in, could I move my caret onto the line containing inlay hints and do something like :insert-inlay-hints?

So far I haven't found anything, but I quickly wanted to check here before submitting a FR.

[mi2ebi]

beware that for some language servers inserting inlay hints would result in compiler diagnostics. for example rust-analyzer's inlay hints include function parameter names, eg f(x: 5), but you're not allowed to actually call functions that way

[a3lem]

Good to know. That'll make it harder to make a case, seeing as Helix is written in Rust.

My experience is mostly with Python language servers, where the hints are valid code. A command like the one suggested would save a lot of typing.

Perhaps others can chime in whether an :insert-inlay-hints might be useful?

For now we have:

Useful:

• ✔️ (based)pyright – Python

Not useful:

• ❌ rust-analyzer – Rust

[the-mikedavis]

This feature should be provided by the language server since it takes language-specific knowledge to know whether the inlay hint is valid code to be inserted. For example with rust-analyzer you can hover over a variable and use a code action (<space>a) to insert the explicit type

[a3lem]

Okay, that gives some indication that what I'm looking for may be outside of Helix's scope. I agree that the language server is in the best position to know what can be safely inserted.

Still – bear with me – many language servers that offer type hints don't offer the same code action as rust-analyzer. As a user, I know what is and isn't valid code. I'm fine assuming the responsibility of deciding. With an :insert-inlay-hint, I'm not dependent on the language server implementing the code action.

But I also understand the need to defend against scope creep. And since my Rust isn't good enough to build this feature, and since a Rust dev won't need it anyway, I'm probably better off seeing if my language server is open to a PR.