Treat doctests as rust code

[ordian]

With syntax highlighting, completion, etc. See https://github.com/intellij-rust/intellij-rust/pull/3144.

[matklad]

The relevant bit of code to look at is https://github.com/rust-analyzer/rust-analyzer/blob/7a9ba1657daa9fd90c639dcd937da11b4f526675/crates/ra_ide/src/syntax_highlighting.rs#L473-L510

[flodiebold]

Well, that's the relevant bit of code just for syntax highlighting, right? For proper analysis, completion etc. this gets even more interesting/fun :smile:

(Conversely, completion in ra_fixture parameters would be cool, if not that useful... And a problem if the fixture is a test for a crash...)

[matklad]

That's another use case for hypothetical, -1 durability things in salsa btw.

[flodiebold]

Hmm doctests don't need to be hypothetical though, right? They could just be normal HIR files, or am I missing something? (Kind of similar to macros)

[matklad]

Hm, I guess we could make them real files, but I'd rather avoid that. Like, we don't want to bust caches when we add an impl to a doc test. More generally, they feel like they should be something which is processed only after everything else is fully analyzed.

[flodiebold]

Well, I guess this is rather hypothetical anyway currently :thinking:

[petr-tik]

looks like this can be closed?

[ordian]

Was completion, type resolution, etc implemented? As far as I see, only syntax highlighting was (which is great btw, thank you!).

[frantisekhanzlikbl]

was #4683 also supposed to work with inner doctests? e.g.: is missing syntax highlighting here intended?

[Veykril]

That should ideally work but doesn't due to the way its currently implemented, see https://github.com/rust-analyzer/rust-analyzer/issues/6873.

[frantisekhanzlikbl]

I am not sure if I missed something, but to me, it seems like #6873 only discusses block comments, but line comments don't work either for me.

[Veykril]

Oh sorry, I misunderstood that. I'm a bit confused though because inner line doc comment highlighting works for me 🤔

Do you have Semantic Highlighting enabled? Without that Doccomment highlighting injection won't work, that is your theme has to support semantic highlighting.

[frantisekhanzlikbl]

Oh, that's my fault - I didn't realise that whether it is enabled or not is by default dependant on the selected theme. After setting "editor.semanticHighlighting.enabled": true everything works as expected.

[Wardenfar]

Hello, Someone knows the steps (or where to look) for implementing completion in doctests ? Maybe just some hints. Thanks

[Veykril]

I don't think we have a clear view on how we want to achieve this yet

[mohe2015]

I think a good workaround is implementing a proc macro that generates the doctests comment from source code. I did this in https://gist.github.com/mohe2015/84725cc7b60040afe2d44fe03a9d5eef. The advantage also is that you don't need to handle the weird /// at the start of every line and in my opinion it just looks nicer. Also line number information seems to be more correct in normal tests than in doctests.

Edit: I hope I have now improved it so it plays nicely with rust-analyzer.

[IceTDrinker]

I'm interested in this if it is planned to include refactoring, i.e. if I'm renaming a function/struct in my code base that the change also gets propagated to docstrings

Maybe by pretending a doctest is a file somehow ? I'm really not familiar with rust analyzer internals, would be curious to know more about this topic

[bionicles]

Would it be possible to implement this the same way normal code is treated? Rust-analyzer is so useful, it's hugely noticeable to not have on doctests (which are simultaneously awesome usage examples, unit tests, and enablers of compile_fail) ... i'd love to see rust-analyzer's feedback on doctest code, doctests are great, more doctest driven development could help the community a lot