diff options
Diffstat (limited to 'src/tools/clippy/clippy_lints/src/methods/repeat_once.rs')
-rw-r--r-- | src/tools/clippy/clippy_lints/src/methods/repeat_once.rs | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/src/tools/clippy/clippy_lints/src/methods/repeat_once.rs b/src/tools/clippy/clippy_lints/src/methods/repeat_once.rs new file mode 100644 index 000000000..0a14f9216 --- /dev/null +++ b/src/tools/clippy/clippy_lints/src/methods/repeat_once.rs @@ -0,0 +1,52 @@ +use clippy_utils::consts::{constant_context, Constant}; +use clippy_utils::diagnostics::span_lint_and_sugg; +use clippy_utils::source::snippet; +use clippy_utils::ty::is_type_diagnostic_item; +use rustc_errors::Applicability; +use rustc_hir::Expr; +use rustc_lint::LateContext; +use rustc_span::sym; + +use super::REPEAT_ONCE; + +pub(super) fn check<'tcx>( + cx: &LateContext<'tcx>, + expr: &'tcx Expr<'_>, + recv: &'tcx Expr<'_>, + repeat_arg: &'tcx Expr<'_>, +) { + if constant_context(cx, cx.typeck_results()).expr(repeat_arg) == Some(Constant::Int(1)) { + let ty = cx.typeck_results().expr_ty(recv).peel_refs(); + if ty.is_str() { + span_lint_and_sugg( + cx, + REPEAT_ONCE, + expr.span, + "calling `repeat(1)` on str", + "consider using `.to_string()` instead", + format!("{}.to_string()", snippet(cx, recv.span, r#""...""#)), + Applicability::MachineApplicable, + ); + } else if ty.builtin_index().is_some() { + span_lint_and_sugg( + cx, + REPEAT_ONCE, + expr.span, + "calling `repeat(1)` on slice", + "consider using `.to_vec()` instead", + format!("{}.to_vec()", snippet(cx, recv.span, r#""...""#)), + Applicability::MachineApplicable, + ); + } else if is_type_diagnostic_item(cx, ty, sym::String) { + span_lint_and_sugg( + cx, + REPEAT_ONCE, + expr.span, + "calling `repeat(1)` on a string literal", + "consider using `.clone()` instead", + format!("{}.clone()", snippet(cx, recv.span, r#""...""#)), + Applicability::MachineApplicable, + ); + } + } +} |