Fill fields triggered from mid-item leaves `{}` appended when completion happens

[nuke-web3]

See helix-editor/helix#8263 for the details (I assumed wrongly this was an IDE issue) for a minimal viable example of the issue and feat req.

triggered the first option:

I would think the empty {} should be omitted.

I also would think that completion options for the incomplete struct name should include one that completes the name and the fields populated with todo!() rather than ().

This is a bug, but a tiny feature request to tweak the behavior of the suggestions when completing an item that has fields that can be filled in.
rust-analyzer version: rust-analyzer 1.72.0 (5680fa1 2023-08-23)

rustc version: rustc 1.72.0 (5680fa18f 2023-08-23)

relevant settings: None

[alibektas]

I could tackle this one in a couple of weeks if it isn't solved by then. But I wonder why is this labeled as a hard to solve issue @Veykril ?

[Veykril]

This is non-trivial to fix because of how our completions architecture works right now. But the bigge problem comes from how the LSP works here, insert vs replace behavior is determined by the client, if the client supports both the server can reply with completion items that describe both behaviors where the client cna then choose which to apply. The way this is done makes this non trivial to implement due to how the text edits are laid out in completion items