diff --git a/clippy_lints/src/matches/redundant_pattern_match.rs b/clippy_lints/src/matches/redundant_pattern_match.rs index c936c96f9719..9d0115791838 100644 --- a/clippy_lints/src/matches/redundant_pattern_match.rs +++ b/clippy_lints/src/matches/redundant_pattern_match.rs @@ -269,66 +269,61 @@ fn find_method_sugg_for_if_let<'tcx>( } pub(super) fn check_match<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, op: &Expr<'_>, arms: &[Arm<'_>]) { - if arms.len() == 2 { - let node_pair = (&arms[0].pat.kind, &arms[1].pat.kind); - - if let Some((good_method, maybe_guard)) = found_good_method(cx, arms, node_pair) { - let span = is_expn_of(expr.span, sym::matches).unwrap_or(expr.span.to(op.span)); - let result_expr = match &op.kind { - ExprKind::AddrOf(_, _, borrowed) => borrowed, - _ => op, - }; - let mut app = Applicability::MachineApplicable; - let receiver_sugg = Sugg::hir_with_applicability(cx, result_expr, "_", &mut app).maybe_paren(); - let mut sugg = format!("{receiver_sugg}.{good_method}"); - - if let Some(guard) = maybe_guard { - // wow, the HIR for match guards in `PAT if let PAT = expr && expr => ...` is annoying! - // `guard` here is `Guard::If` with the let expression somewhere deep in the tree of exprs, - // counter to the intuition that it should be `Guard::IfLet`, so we need another check - // to see that there aren't any let chains anywhere in the guard, as that would break - // if we suggest `t.is_none() && (let X = y && z)` for: - // `match t { None if let X = y && z => true, _ => false }` - let has_nested_let_chain = for_each_expr_without_closures(guard, |expr| { - if matches!(expr.kind, ExprKind::Let(..)) { - ControlFlow::Break(()) - } else { - ControlFlow::Continue(()) - } - }) - .is_some(); - - if has_nested_let_chain { - return; + if let Ok(arms) = arms.try_into() // TODO: use `slice::as_array` once stabilized + && let Some((good_method, maybe_guard)) = found_good_method(cx, arms) + { + let span = is_expn_of(expr.span, sym::matches).unwrap_or(expr.span.to(op.span)); + let result_expr = match &op.kind { + ExprKind::AddrOf(_, _, borrowed) => borrowed, + _ => op, + }; + let mut app = Applicability::MachineApplicable; + let receiver_sugg = Sugg::hir_with_applicability(cx, result_expr, "_", &mut app).maybe_paren(); + let mut sugg = format!("{receiver_sugg}.{good_method}"); + + if let Some(guard) = maybe_guard { + // wow, the HIR for match guards in `PAT if let PAT = expr && expr => ...` is annoying! + // `guard` here is `Guard::If` with the let expression somewhere deep in the tree of exprs, + // counter to the intuition that it should be `Guard::IfLet`, so we need another check + // to see that there aren't any let chains anywhere in the guard, as that would break + // if we suggest `t.is_none() && (let X = y && z)` for: + // `match t { None if let X = y && z => true, _ => false }` + let has_nested_let_chain = for_each_expr_without_closures(guard, |expr| { + if matches!(expr.kind, ExprKind::Let(..)) { + ControlFlow::Break(()) + } else { + ControlFlow::Continue(()) } + }) + .is_some(); - let guard = Sugg::hir(cx, guard, ".."); - let _ = write!(sugg, " && {}", guard.maybe_paren()); + if has_nested_let_chain { + return; } - span_lint_and_sugg( - cx, - REDUNDANT_PATTERN_MATCHING, - span, - format!("redundant pattern matching, consider using `{good_method}`"), - "try", - sugg, - app, - ); + let guard = Sugg::hir(cx, guard, ".."); + let _ = write!(sugg, " && {}", guard.maybe_paren()); } + + span_lint_and_sugg( + cx, + REDUNDANT_PATTERN_MATCHING, + span, + format!("redundant pattern matching, consider using `{good_method}`"), + "try", + sugg, + app, + ); } } fn found_good_method<'tcx>( cx: &LateContext<'_>, - arms: &'tcx [Arm<'tcx>], - node: (&PatKind<'_>, &PatKind<'_>), + arms: &'tcx [Arm<'tcx>; 2], ) -> Option<(&'static str, Option<&'tcx Expr<'tcx>>)> { - match node { - (PatKind::TupleStruct(path_left, patterns_left, _), PatKind::TupleStruct(path_right, patterns_right, _)) - if patterns_left.len() == 1 && patterns_right.len() == 1 => - { - if let (PatKind::Wild, PatKind::Wild) = (&patterns_left[0].kind, &patterns_right[0].kind) { + match (&arms[0].pat.kind, &arms[1].pat.kind) { + (PatKind::TupleStruct(path_left, [pattern_left], _), PatKind::TupleStruct(path_right, [pattern_right], _)) => { + if let (PatKind::Wild, PatKind::Wild) = (&pattern_left.kind, &pattern_right.kind) { find_good_method_for_match( cx, arms, @@ -356,7 +351,7 @@ fn found_good_method<'tcx>( } }, ( - PatKind::TupleStruct(path_left, patterns, _), + PatKind::TupleStruct(path_left, [pattern], _), PatKind::Expr(PatExpr { kind: PatExprKind::Path(path_right), .. @@ -367,9 +362,9 @@ fn found_good_method<'tcx>( kind: PatExprKind::Path(path_left), .. }), - PatKind::TupleStruct(path_right, patterns, _), - ) if patterns.len() == 1 => { - if let PatKind::Wild = patterns[0].kind { + PatKind::TupleStruct(path_right, [pattern], _), + ) => { + if let PatKind::Wild = pattern.kind { find_good_method_for_match( cx, arms, @@ -396,8 +391,8 @@ fn found_good_method<'tcx>( None } }, - (PatKind::TupleStruct(path_left, patterns, _), PatKind::Wild) if patterns.len() == 1 => { - if let PatKind::Wild = patterns[0].kind { + (PatKind::TupleStruct(path_left, [pattern], _), PatKind::Wild) => { + if let PatKind::Wild = pattern.kind { get_good_method(cx, arms, path_left) } else { None @@ -426,31 +421,23 @@ fn get_ident(path: &QPath<'_>) -> Option { fn get_good_method<'tcx>( cx: &LateContext<'_>, - arms: &'tcx [Arm<'tcx>], + arms: &'tcx [Arm<'tcx>; 2], path_left: &QPath<'_>, ) -> Option<(&'static str, Option<&'tcx Expr<'tcx>>)> { - if let Some(name) = get_ident(path_left) { - let (expected_item_left, should_be_left, should_be_right) = match name.as_str() { - "Ok" => (Item::Lang(ResultOk), "is_ok()", "is_err()"), - "Err" => (Item::Lang(ResultErr), "is_err()", "is_ok()"), - "Some" => (Item::Lang(OptionSome), "is_some()", "is_none()"), - "None" => (Item::Lang(OptionNone), "is_none()", "is_some()"), - "Ready" => (Item::Lang(PollReady), "is_ready()", "is_pending()"), - "Pending" => (Item::Lang(PollPending), "is_pending()", "is_ready()"), - "V4" => (Item::Diag(sym::IpAddr, sym::V4), "is_ipv4()", "is_ipv6()"), - "V6" => (Item::Diag(sym::IpAddr, sym::V6), "is_ipv6()", "is_ipv4()"), - _ => return None, - }; - return find_good_method_for_matches_macro( - cx, - arms, - path_left, - expected_item_left, - should_be_left, - should_be_right, - ); - } - None + let ident = get_ident(path_left)?; + + let (expected_item_left, should_be_left, should_be_right) = match ident.name { + sym::Ok => (Item::Lang(ResultOk), "is_ok()", "is_err()"), + sym::Err => (Item::Lang(ResultErr), "is_err()", "is_ok()"), + sym::Some => (Item::Lang(OptionSome), "is_some()", "is_none()"), + sym::None => (Item::Lang(OptionNone), "is_none()", "is_some()"), + sym::Ready => (Item::Lang(PollReady), "is_ready()", "is_pending()"), + sym::Pending => (Item::Lang(PollPending), "is_pending()", "is_ready()"), + sym::V4 => (Item::Diag(sym::IpAddr, sym::V4), "is_ipv4()", "is_ipv6()"), + sym::V6 => (Item::Diag(sym::IpAddr, sym::V6), "is_ipv6()", "is_ipv4()"), + _ => return None, + }; + find_good_method_for_matches_macro(cx, arms, path_left, expected_item_left, should_be_left, should_be_right) } #[derive(Clone, Copy)] @@ -490,7 +477,7 @@ fn is_pat_variant(cx: &LateContext<'_>, pat: &Pat<'_>, path: &QPath<'_>, expecte #[expect(clippy::too_many_arguments)] fn find_good_method_for_match<'a, 'tcx>( cx: &LateContext<'_>, - arms: &'tcx [Arm<'tcx>], + arms: &'tcx [Arm<'tcx>; 2], path_left: &QPath<'_>, path_right: &QPath<'_>, expected_item_left: Item, @@ -525,7 +512,7 @@ fn find_good_method_for_match<'a, 'tcx>( fn find_good_method_for_matches_macro<'a, 'tcx>( cx: &LateContext<'_>, - arms: &'tcx [Arm<'tcx>], + arms: &'tcx [Arm<'tcx>; 2], path_left: &QPath<'_>, expected_item_left: Item, should_be_left: &'a str,