`wildcard_imports` is ignored in test crates

[Nemo157]

Summary

The wildcard_imports lint is skipped in all test crates. This is an explicit choice of the lint, but I wasn't able to find any history explaining why, the blame points to a merge commit.

rust-clippy/clippy_lints/src/wildcard_imports.rs

Lines 119 to 121 in 8f3cfb4

	if cx.sess().is_test_crate() {
	return;
	}

Lint Name

wildcard_imports

Reproducer

I tried this code:

use core::pin::*;

pub fn foo() {
    pin!(());
}

#[cfg(test)]
mod tests {
    use std::pin::*;

    #[test]
    fn foo() {
        pin!(());
    }
}

I expected to see this happen: two warnings about wildcard imports

Instead, this happened: only one warning about wildcard imports

> cargo clippy --all-targets -v -j1 -- -Wclippy::wildcard_imports
       Dirty foo v0.1.0 (/tmp/scratch.rust-unwrapped.2024-07-30T10-06.w3DuOq/foo): the file `src/lib.rs` has changed (1722328852.132977234s, 39s after last build at 1722328813.510891614s)
    Checking foo v0.1.0 (/tmp/scratch.rust-unwrapped.2024-07-30T10-06.w3DuOq/foo)
     Running `/nix/store/i1zng12k5g9x2p0pl3nhd1sjg3xa8m7n-rust-minimal-1.82.0-nightly-2024-07-27/bin/clippy-driver rustc --crate-name foo --edition=2021 src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --diagnostic-width=414 --emit=dep-info,metadata -C embed-bitcode=no -C debuginfo=2 --test --check-cfg 'cfg(docsrs)' --check-cfg 'cfg(feature, values())' -C metadata=4c9c1f22b2f5ad41 -C extra-filename=-4c9c1f22b2f5ad41 --out-dir /run/user/1000/cargo-home/target/shared/debug/deps -C incremental=/run/user/1000/cargo-home/target/shared/debug/incremental -L dependency=/run/user/1000/cargo-home/target/shared/debug/deps`
     Running `/nix/store/i1zng12k5g9x2p0pl3nhd1sjg3xa8m7n-rust-minimal-1.82.0-nightly-2024-07-27/bin/clippy-driver rustc --crate-name foo --edition=2021 src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --diagnostic-width=414 --crate-type lib --emit=dep-info,metadata -C embed-bitcode=no -C debuginfo=2 --check-cfg 'cfg(docsrs)' --check-cfg 'cfg(feature, values())' -C metadata=12419aaa3a6411f5 -C extra-filename=-12419aaa3a6411f5 --out-dir /run/user/1000/cargo-home/target/shared/debug/deps -C incremental=/run/user/1000/cargo-home/target/shared/debug/incremental -L dependency=/run/user/1000/cargo-home/target/shared/debug/deps`
warning: usage of wildcard import
 --> src/lib.rs:1:5
  |
1 | use core::pin::*;
  |     ^^^^^^^^^^^^ help: try: `core::pin::pin`
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#wildcard_imports
  = note: requested on the command line with `-W clippy::wildcard-imports`

warning: `foo` (lib) generated 1 warning (run `cargo clippy --fix --lib -p foo` to apply 1 suggestion)
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.10s

Version

rustc 1.82.0-nightly (7c2012d0e 2024-07-26)
binary: rustc
commit-hash: 7c2012d0ec3aae89fefc40e5d6b317a0949cda36
commit-date: 2024-07-26
host: x86_64-unknown-linux-gnu
release: 1.82.0-nightly
LLVM version: 18.1.7

[y21]

I wasn't able to find any history explaining why, the blame points to a merge commit.

Looks like the check was added in #10584 (which links to an issue with some reasoning)

[Nemo157]

I strongly disagree with having a blanket allow though, there's already logic around allowing special cases like use super::*; in test modules (though personally I want to run this with all the special cases disabled, IMO it's always an improvement to use explicit imports, especially in tests).

If someone wants to blanket allow it in tests, they can simply #![cfg_attr(test, allow(clippy::wildcard_imports))] the same as any other lint.