Consider configuring Clippy

[vipentti]

According to rust-lang/rust-clippy#configuration:

Some lints can be configured in a TOML file named clippy.toml or .clippy.toml. It contains a basic variable = value mapping eg.

We could consider adding Clippy configuration to allow running cargo clippy on rust-analyzer while developing without reporting large number of warnings that are not relevant to rust-analyzer.

For the lints that currently cannot be configured in a TOML file we can ignore those (allow those to report warnings) or add some "global" inner attributes that allow them.

I think ideally running cargo clippy on rust-analyzer should return no warnings / errors even if it means we allow some lints to pass. This could help people trying to contribute with creating more idiomatic solutions.

[matklad]

I personally don't use clippy much, because, while it does find a number of legit issues, it also tends to find a significant number of false-positives (examples) and blindly fixing those usually makes code worse. I am also not a fan of suppressing warnings on each individual expression/function, etc, as that also makes code less readable for trivial reasons.

Disabling lints in .toml sounds great to me! Is there some preconfigured set of lints with no false positives?

[vipentti]

Looks like the actual Enabling/Disabling lints through the config is still pending according to rust-lang/rfcs#2476 (comment) and rust-lang/cargo#5034

I guess an alternative, since clippy allows passing lints as flags to cargo clippy e.g. cargo clippy -- -A clippy::lint_name, we could provide an alias or a set of flags in some document that would allow running the lints that rust-analyzer may be interested in.

It may even make sense to have cargo clippy -- -A clippy::all as the default and then having some explicit -D flags for denying particular types of lints.

[matklad]

I guess an alternative, since clippy allows passing lints as flags to cargo clippy e.g. cargo clippy -- -A clippy::lint_name, we could provide an alias or a set of flags in some document that would allow running the lints that rust-analyzer may be interested in.

We can add cargo lint command to the tools infra, the same way we added cargo format.

[matklad]

we have cargo xtask lint now