1 use clippy_utils::diagnostics::span_lint_and_sugg;
2 use clippy_utils::source::snippet_with_applicability;
3 use clippy_utils::ty::is_type_diagnostic_item;
4 use if_chain::if_chain;
5 use rustc_errors::Applicability;
7 use rustc_lint::LateContext;
10 use super::BYTES_COUNT_TO_LEN;
12 pub(super) fn check<'tcx>(
13 cx: &LateContext<'tcx>,
14 expr: &'tcx hir::Expr<'_>,
15 count_recv: &'tcx hir::Expr<'_>,
16 bytes_recv: &'tcx hir::Expr<'_>,
19 if let Some(bytes_id) = cx.typeck_results().type_dependent_def_id(count_recv.hir_id);
20 if let Some(impl_id) = cx.tcx.impl_of_method(bytes_id);
21 if cx.tcx.type_of(impl_id).is_str();
22 let ty = cx.typeck_results().expr_ty(bytes_recv).peel_refs();
23 if ty.is_str() || is_type_diagnostic_item(cx, ty, sym::String);
25 let mut applicability = Applicability::MachineApplicable;
30 "using long and hard to read `.bytes().count()`",
31 "consider calling `.len()` instead",
32 format!("{}.len()", snippet_with_applicability(cx, bytes_recv.span, "..", &mut applicability)),