internal: Migrate assists to the structured snippet API, part 3
Continuing from #15231
Migrates the following assists:
- `add_missing_match_arms`
- `fix_visibility`
- `promote_local_to_const`
The `add_missing_match_arms` changes are best reviewed commit-by-commit since they're relatively big changes compared to the rest of the commits.
`clone_for_update` is relatively cheap in comparison, since making a
node require parsing an entire source text
Adds a test to make sure that it doesn't crash when multiple uses are
present.
[lsp-server] Ignore 'Content-Length' case
this is a trivial PR meant to address issue #15197: the 'Content-Length' header field should probably be treated as case-insensitive
Skip building subtrees for builtin derives
This is a waste of resources, we go from node to subtree just to go from subtree to node in the expander impl. We can skip the subtree building and only build the tokenmap instead.
internal: Migrate more assists to use the structured snippet API
Continuing from #14979
Migrates the following assists:
- `generate_derive`
- `wrap_return_type_in_result`
- `generate_delegate_methods`
As a bonus, `generate_delegate_methods` now generates the function and impl block at the correct indentation 🎉.
Feature: Add a memory layout viewer
**Motivation**: rustc by default doesn't enforce a particular memory layout, however it can be useful to see what it is doing under the hood, or if using a particular repr ensure it is behaving how you want it to. This command provides a way to visually explore memory layouts of structures.
**Example**:
this structure:
```rust
struct X {
x: i32,
y: u8,
z: Vec<bool>,
w: usize,
}
```
produces this output:
<img width="692" alt="image" src="https://github.com/rust-lang/rust-analyzer/assets/22418744/e0312233-18a7-4bb9-ae5b-7b52fcff158a">
**Work yet to be done**:
- tests (see below)
- html is mildly janky (see below)
- enums and unions are viewed flatly, how should they be represented?
- should niches be marked somehow?
This was written for my own use, and the jank is fine for me, but in its current state it is probably not ready to merge mostly because it is missing tests, and also because the code quality is not great. However, before I spend time fixing those things idk if this is even something wanted, if it is I am happy to clean it up, if not that's cool too.
`does_not_fill_wildcard_with_wildcard`
and `does_not_fill_wildcard_with_partial_wildcard_and_wildcard`
both made no modifications to the code,
which is a problem for mutable ast porting as it generates a best-effort
minimal set of text edits,
and assists require at least one text edit.
Stop inserting semicolon when extracting match arm
# Overview
Extracting a match arm value that has type unit into a function, when a
comma already follows the match arm value, results in an invalid (syntax
error) semicolon added between the newly generated function's generated
call and the comma.
# Example
Running this extraction
```rust
fn main() {
match () {
_ => $0()$0,
};
}
```
would lead to
```rust
fn main() {
match () {
_ => fun_name();,
};
}
fn fun_name() {
}
```
# Issue / Fix details
This happens because when there is no comma, rust-analyzer would simply
add the comma and wouldn't even try to evaluate whether it needs to add
a semicolon. But when the comma is there, it proceeds to evaluate
whether it needs to add a semicolon and it looks like the evaluation
logic erroneously ignores the possibility that we're in a match arm.
IIUC it never makes sense to add a semicolon when we're extracting from
a match arm value, so I've adjusted the logic to always decide against
adding a semicolon when we're in a match arm
