rust-clippy/clippy_lints/src/tests_outside_test_module.rs
Kevin Reid 0f5338cd90 For restriction lints, replace “Why is this bad?” with “Why restrict this?”
The `restriction` group contains many lints which are not about
necessarily “bad” things, but style choices — perhaps even style choices
which contradict conventional Rust style — or are otherwise very
situational. This results in silly wording like “Why is this bad?
It isn't, but ...”, which I’ve seen confuse a newcomer at least once.

To improve this situation, this commit replaces the “Why is this bad?”
section heading with “Why restrict this?”, for most, but not all,
restriction lints. I left alone the ones whose placement in the
restriction group is more incidental.

In order to make this make sense, I had to remove the “It isn't, but”
texts from the contents of the sections. Sometimes further changes
were needed, or there were obvious fixes to make, and I went ahead
and made those changes without attempting to split them into another
commit, even though many of them are not strictly necessary for the
“Why restrict this?” project.
2024-05-23 15:51:33 -07:00

74 lines
2.1 KiB
Rust

use clippy_utils::diagnostics::span_lint_and_note;
use clippy_utils::{is_in_cfg_test, is_in_test_function};
use rustc_hir::intravisit::FnKind;
use rustc_hir::{Body, FnDecl};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::declare_lint_pass;
use rustc_span::def_id::LocalDefId;
use rustc_span::Span;
declare_clippy_lint! {
/// ### What it does
/// Triggers when a testing function (marked with the `#[test]` attribute) isn't inside a testing module
/// (marked with `#[cfg(test)]`).
///
/// ### Why restrict this?
/// The idiomatic (and more performant) way of writing tests is inside a testing module (flagged with `#[cfg(test)]`),
/// having test functions outside of this module is confusing and may lead to them being "hidden".
///
/// ### Example
/// ```no_run
/// #[test]
/// fn my_cool_test() {
/// // [...]
/// }
///
/// #[cfg(test)]
/// mod tests {
/// // [...]
/// }
///
/// ```
/// Use instead:
/// ```no_run
/// #[cfg(test)]
/// mod tests {
/// #[test]
/// fn my_cool_test() {
/// // [...]
/// }
/// }
/// ```
#[clippy::version = "1.70.0"]
pub TESTS_OUTSIDE_TEST_MODULE,
restriction,
"A test function is outside the testing module."
}
declare_lint_pass!(TestsOutsideTestModule => [TESTS_OUTSIDE_TEST_MODULE]);
impl LateLintPass<'_> for TestsOutsideTestModule {
fn check_fn(
&mut self,
cx: &LateContext<'_>,
kind: FnKind<'_>,
_: &FnDecl<'_>,
body: &Body<'_>,
sp: Span,
_: LocalDefId,
) {
if !matches!(kind, FnKind::Closure)
&& is_in_test_function(cx.tcx, body.id().hir_id)
&& !is_in_cfg_test(cx.tcx, body.id().hir_id)
{
span_lint_and_note(
cx,
TESTS_OUTSIDE_TEST_MODULE,
sp,
"this function marked with #[test] is outside a #[cfg(test)] module",
None,
"move it to a testing module marked with #[cfg(test)]",
);
}
}
}