There are few things to note in the implementation:
First, this is a best-effort implementation. Mainly, type aliases may not be shown (due to their eager nature it's harder) and partial pathes (aka. hovering over `Struct` in `Struct::method`) are not supported at all.
Second, we only need to show substitutions in expression and pattern position, because in type position all generic arguments always have to be written explicitly.
internal: Send less data during `textDocument/completion` if possible
Similar to https://github.com/rust-lang/rust-analyzer/pull/15522, stops sending extra data during `textDocument/completion` if that data was set in the client completions resolve capabilities, and sends those only during `completionItem/resolve` requests.
Currently, rust-analyzer sends back all fields (including potentially huge docs) for every completion item which might get large.
Same as the other one, this PR aims to keep the changes minimal and does not remove extra computations for such fields — instead, it just filters them out before sending to the client.
The PR omits primitive, boolean and integer, types such as `deprecated`, `preselect`, `insertTextFormat`, `insertTextMode`, etc. AND `additionalTextEdits` — this one looks very dangerous to compute for each completion item (as the spec says we ought to if there's no corresponding resolve capabilities provided) due to the diff computations and the fact that this code had been in the resolution for some time.
It would be good to resolve this lazily too, please let me know if it's ok to do.
When tested with Zed which only defines `documentation` and `additionalTextEdits` in its client completion resolve capabilities, rust-analyzer starts to send almost 3 times less characters:
Request:
```json
{"jsonrpc":"2.0","id":104,"method":"textDocument/completion","params":{"textDocument":{"uri":"file:///Users/someonetoignore/work/rust-analyzer/crates/ide/src/inlay_hints.rs"},"position":{"line":90,"character":14},"context":{"triggerKind":1}}}
```
<img width="1338" alt="image" src="https://github.com/user-attachments/assets/104f19b5-7095-4fc1-b008-5d829623b2e2">
Before: 381944 characters
[before.json](https://github.com/user-attachments/files/17092385/before.json)
After: 140503 characters
[after.json](https://github.com/user-attachments/files/17092386/after.json)
After Zed's [patch](https://github.com/zed-industries/zed/pull/18212) to enable all resolving possible: 84452 characters
[after-after.json](https://github.com/user-attachments/files/17092755/after-after.json)
internal: Better testing infra for ratoml
This PR makes some improvements on how we test configs that come from `rust-analyzer.toml` files.
It was primarily used to solve #18021 but along the way I could not really determine the cause of the said issue which makes me think that it may not be related to the changes that I made earlier to the ratoml infra. In either way `custom_snippets` are now made `global` because we still don't have a tree that maps a `SourceRootId` to a set of `Snippet`s.
But provide a config to suppress that.
I didn't check whether we are in statement expression position, because this is hard in completion (due to the natural incompleteness of source code when completion is invoked), and anyway using function returning unit as an argument to something seems... dubious.
These flags were added to help rust-analyzer integrate with repos
requiring non-Cargo invocations. The consensus is that having two
independent settings are no longer needed. This change removes
`invocationLocation` in favor of `invocationStrategy` and changes
the internal representation of `InvocationStrategy::Once` to hold
the workspace root.
feat: Use spans for builtin and declarative macro expansion errors
This should generally improve some error reporting for macro expansion errors. Especially for `compile_error!` within proc-macros
