1 use clippy_utils::diagnostics::span_lint_and_sugg;
2 use clippy_utils::method_chain_args;
3 use clippy_utils::source::snippet_with_applicability;
4 use clippy_utils::ty::is_type_lang_item;
5 use rustc_errors::Applicability;
7 use rustc_lint::LateContext;
10 use super::STRING_EXTEND_CHARS;
12 pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, recv: &hir::Expr<'_>, arg: &hir::Expr<'_>) {
13 let obj_ty = cx.typeck_results().expr_ty(recv).peel_refs();
14 if !is_type_lang_item(cx, obj_ty, hir::LangItem::String) {
17 if let Some(arglists) = method_chain_args(arg, &["chars"]) {
18 let target = &arglists[0].0;
19 let self_ty = cx.typeck_results().expr_ty(target).peel_refs();
20 let ref_str = if *self_ty.kind() == ty::Str {
21 if matches!(target.kind, hir::ExprKind::Index(..)) {
26 } else if is_type_lang_item(cx, self_ty, hir::LangItem::String) {
32 let mut applicability = Applicability::MachineApplicable;
37 "calling `.extend(_.chars())`",
40 "{}.push_str({ref_str}{})",
41 snippet_with_applicability(cx, recv.span, "..", &mut applicability),
42 snippet_with_applicability(cx, target.span, "..", &mut applicability)