feat: enable excluding refs search results in test

[Young-Flash]

Change

Here I introduce a new ReferenceCategory::Test type to indicate whether the function where this reference is located is marked as #[test], and expose an config item (rust-analyzer.references.excludeTests) to client.

I also changed the signature of ReferenceCategory::new, adding a sema: &Semantics<'_, RootDatabase> param to do some hir analysis. Hope the current implementation is good to go.

Demo

"rust-analyzer.references.excludeTests": false

"rust-analyzer.references.excludeTests": true

Performance

I look a bit more about the latency in rust-analyzer server LSP log trace, compared the Find All References between v0.4.1825 and this PR over syntax::ast::AstNode::syntax() and ide_assists::tests::check_assist(), taking an average of 5 operations response time (every operation is perform after restart rust-analyzer server so it's not the cache reslut). I found this PR does't bring noticable regression.

item	excludeTests?	v0.4.1825	this PR	ref results
syntax::ast::AstNode::syntax	false	13329.4 ms	13464.2 ms	2419 results in 257 files
syntax::ast::AstNode::syntax	true	-	13449.0 ms	2396 results in 256 files
ide_assists::tests::check_assist	false	333.2 ms	348.2 ms	1684 results in 110 files
ide_assists::tests::check_assist	true	-	335.6 ms	113 results in 110 files

close #14530

[Young-Flash]

I look a bit more about the latency in rust-analyzer server LSP log trace, compared the Find All References between v0.4.1825 and this PR over syntax::ast::AstNode::syntax() and ide_assists::tests::check_assist(), taking an average of 5 operations response time (every operation is perform after restart rust-analyzer server so it's not the cache reslut). I found this PR does't bring noticable regression.

item	excludeTests?	v0.4.1825	this PR	ref results
syntax::ast::AstNode::syntax	false	13329.4 ms	13464.2 ms	2419 results in 257 files
syntax::ast::AstNode::syntax	true	-	13449.0 ms	2396 results in 256 files
ide_assists::tests::check_assist	false	333.2 ms	348.2 ms	1684 results in 110 files
ide_assists::tests::check_assist	true	-	335.6 ms	113 results in 110 files

[Veykril]

@bors r+

[bors]

📌 Commit 2b71aca has been approved by Veykril

It is now in the queue for this repository.

[bors]

⌛ Testing commit 2b71aca with merge e4146af...

[bors]

☀️ Test successful - checks-actions
Approved by: Veykril
Pushing e4146af to master...

[matklad]

Great to see this! Supporting this feature is exactly why the search API was designed as it was, with reference categories and such!

[matklad]

exclude_tests should be pushed down as a parameter to find_all_refs.

that way, a potentially more optimal implementation would be able to avoid even analyzing the test, which would be faster than filtering out results after the fact.

I think the second parameter we are passing here, which is currently None, is something like a SearchScope. It exists exactly to narrow down search results, and I think could be extended to exclude tests.

[Young-Flash]

good point, I had create an issue for this

(sorry for the slow response, kind of busy recently)

[matklad]

Something can be a test and a read at the same time. So, the time has come to use a bitset here! This is precisely the situation the old comment just above this line talks about

[glasser]

I just discovered this and I'm really excited, as I've wanted this in VSCode for years!

It looks like this filters out things inside #[test] functions, but not inside blocks marked with #[cfg(test)]. Is this intentional? I really just want to find references in my actual production code, skipping both tests and test-support code.

[Young-Flash]

it is not intentional, just forgot #[cfg(test)]

[glasser]

Ah cool. Should I file an issue about this?

[Young-Flash]

yeah, you can also try to implement it

rust-analyzer/crates/ide-db/src/search.rs

Lines 1358 to 1363 in ab44866

	fn is_name_ref_in_test(sema: &Semantics<'_, RootDatabase>, name_ref: &ast::NameRef) -> bool {
	name_ref.syntax().ancestors().any(|node| match ast::Fn::cast(node) {
	Some(it) => sema.to_def(&it).map_or(false, |func| func.is_test(sema.db)),
	None => false,
	})
	}