rust/clippy_lints/src/methods/repeat_once.rs
2022-08-19 10:54:55 -04:00

53 lines
1.8 KiB
Rust

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,
);
}
}
}