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_diagnostic_item;
5 use rustc_errors::Applicability;
7 use rustc_lint::LateContext;
9 use rustc_span::symbol::sym;
11 use super::STRING_EXTEND_CHARS;
13 pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, recv: &hir::Expr<'_>, arg: &hir::Expr<'_>) {
14 let obj_ty = cx.typeck_results().expr_ty(recv).peel_refs();
15 if !is_type_diagnostic_item(cx, obj_ty, sym::string_type) {
18 if let Some(arglists) = method_chain_args(arg, &["chars"]) {
19 let target = &arglists[0][0];
20 let self_ty = cx.typeck_results().expr_ty(target).peel_refs();
21 let ref_str = if *self_ty.kind() == ty::Str {
23 } else if is_type_diagnostic_item(cx, self_ty, sym::string_type) {
29 let mut applicability = Applicability::MachineApplicable;
34 "calling `.extend(_.chars())`",
38 snippet_with_applicability(cx, recv.span, "..", &mut applicability),
40 snippet_with_applicability(cx, target.span, "..", &mut applicability)