**Run** should run doctests

[matklad]

Relevant code:

• https://github.com/rust-analyzer/rust-analyzer/blob/d1c1c01309cff76f6ba60c845500f67a1ca6cec6/crates/ra_ide/src/runnables.rs#L43 -- here we decide if there's a test under cursor
• https://github.com/rust-analyzer/rust-analyzer/blob/d1c1c01309cff76f6ba60c845500f67a1ca6cec6/crates/rust-analyzer/src/main_loop/handlers.rs#L377 -- here we convert "test under cursor" into json we send to LSP client
• https://github.com/rust-analyzer/rust-analyzer/blob/d1c1c01309cff76f6ba60c845500f67a1ca6cec6/editors/code/src/commands/runnables.ts#L9 -- here we run the actual tests

[bnjjj]

Hmm seems not so easy, in fact regarding these issues on cargo rust-lang/cargo#6424 and rust-lang/cargo#6669 the --all-targets seems to not test all targets :(

Then a proposal should be to add a new command suggest to just launch doc test with --doc flag. What do you think ?

[matklad]

I think the linked cargo issues are irrelevant here? We should just generate cargo test --doc -- name::of::the::test command (ie, just adding --doc to what we do already).

[bnjjj]

Maybe I didn't understood the issue but your linked source code seems to be linked to cargo test --package my_package_name (https://github.com/rust-analyzer/rust-analyzer/blob/d1c1c01309cff76f6ba60c845500f67a1ca6cec6/crates/rust-analyzer/src/main_loop/handlers.rs#L403) and then if we add --doc it won't test unit tests anymore.

[edwin0cheng]

One of the disadvantages to using cargo test --doc --name::of::the::test is it only support library target:

--doc
    Test only the library’s documentation. This cannot be mixed with other target options.

Maybe we could use rustdoc --test --test-args="name::of::the::test" src/main.rs ?

[matklad]

I think doc tests outside of the --lib are a niche use-case to begin with, so I'd start with only supporting --doc and doing something custom only when we get a bug report.

[matklad]

@bnjjj this is about running a single test, which goes via this code path.

[edwin0cheng]

--bin is common use case too :) , But of course I think starting from simplest is right.

[bjorn3]

According to that same page doc tests are only tested for lib targets, which is not true. This is probably outdated documentation.

When no target selection options are given, cargo test will build the following targets of the selected packages:
[...]

• doc tests for the lib target

[matklad]

Hm, but doc tests just don't work in --bin?

rust-lang/rust#50784

[bjorn3]

I assumed they work.