1 use super::utils::derefs_to_slice;
2 use clippy_utils::diagnostics::span_lint_and_sugg;
3 use clippy_utils::source::snippet_with_applicability;
4 use clippy_utils::ty::{is_type_diagnostic_item, match_type};
5 use clippy_utils::{get_parent_expr, paths};
6 use if_chain::if_chain;
7 use rustc_errors::Applicability;
9 use rustc_lint::LateContext;
12 use super::GET_UNWRAP;
14 pub(super) fn check<'tcx>(
15 cx: &LateContext<'tcx>,
17 recv: &'tcx hir::Expr<'tcx>,
18 get_arg: &'tcx hir::Expr<'_>,
21 // Note: we don't want to lint `get_mut().unwrap` for `HashMap` or `BTreeMap`,
22 // because they do not implement `IndexMut`
23 let mut applicability = Applicability::MachineApplicable;
24 let expr_ty = cx.typeck_results().expr_ty(recv);
25 let get_args_str = snippet_with_applicability(cx, get_arg.span, "..", &mut applicability);
27 let caller_type = if derefs_to_slice(cx, recv, expr_ty).is_some() {
28 needs_ref = get_args_str.parse::<usize>().is_ok();
30 } else if is_type_diagnostic_item(cx, expr_ty, sym::vec_type) {
31 needs_ref = get_args_str.parse::<usize>().is_ok();
33 } else if is_type_diagnostic_item(cx, expr_ty, sym::vecdeque_type) {
34 needs_ref = get_args_str.parse::<usize>().is_ok();
36 } else if !is_mut && is_type_diagnostic_item(cx, expr_ty, sym::hashmap_type) {
39 } else if !is_mut && match_type(cx, expr_ty, &paths::BTREEMAP) {
43 return; // caller is not a type that we want to lint
46 let mut span = expr.span;
48 // Handle the case where the result is immediately dereferenced
49 // by not requiring ref and pulling the dereference into the
53 if let Some(parent) = get_parent_expr(cx, expr);
54 if let hir::ExprKind::Unary(hir::UnOp::Deref, _) = parent.kind;
61 let mut_str = if is_mut { "_mut" } else { "" };
62 let borrow_str = if !needs_ref {
75 "called `.get{0}().unwrap()` on a {1}. Using `[]` is more clear and more concise",
82 snippet_with_applicability(cx, recv.span, "..", &mut applicability),