New lint: unnecessary_map_or

CHANGELOG.md

@@ -6071,6 +6071,7 @@ Released 2018-09-13
 [`unnecessary_literal_bound`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_literal_bound
 [`unnecessary_literal_unwrap`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_literal_unwrap
 [`unnecessary_map_on_constructor`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_map_on_constructor
+[`unnecessary_map_or`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_map_or
 [`unnecessary_min_or_max`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_min_or_max
 [`unnecessary_mut_passed`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_mut_passed
 [`unnecessary_operation`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_operation

clippy_dev/src/setup/vscode.rs

@@ -84,7 +84,7 @@ fn delete_vs_task_file(path: &Path) -> bool {
 /// It may fail silently.
 fn try_delete_vs_directory_if_empty() {
     let path = Path::new(VSCODE_DIR);
-    if path.read_dir().map_or(false, |mut iter| iter.next().is_none()) {
+    if path.read_dir().is_ok_and(|mut iter| iter.next().is_none()) {
         // The directory is empty. We just try to delete it but allow a silence
         // fail as an empty `.vscode` directory is still valid
         let _silence_result = fs::remove_dir(path);

clippy_lints/src/attrs/useless_attribute.rs

@@ -16,7 +16,7 @@ pub(super) fn check(cx: &EarlyContext<'_>, item: &Item, attrs: &[Attribute]) {
             return;
         }
         if let Some(lint_list) = &attr.meta_item_list() {
-            if attr.ident().map_or(false, |ident| is_lint_level(ident.name, attr.id)) {
+            if attr.ident().is_some_and(|ident| is_lint_level(ident.name, attr.id)) {
                 for lint in lint_list {
                     match item.kind {
                         ItemKind::Use(..) => {

clippy_lints/src/attrs/utils.rs

@@ -50,7 +50,7 @@ fn is_relevant_block(cx: &LateContext<'_>, typeck_results: &ty::TypeckResults<'_
         block
             .expr
             .as_ref()
-            .map_or(false, |e| is_relevant_expr(cx, typeck_results, e)),
+            .is_some_and(|e| is_relevant_expr(cx, typeck_results, e)),
         |stmt| match &stmt.kind {
             StmtKind::Let(_) => true,
             StmtKind::Expr(expr) | StmtKind::Semi(expr) => is_relevant_expr(cx, typeck_results, expr),
@@ -60,7 +60,7 @@ fn is_relevant_block(cx: &LateContext<'_>, typeck_results: &ty::TypeckResults<'_
 }
 
 fn is_relevant_expr(cx: &LateContext<'_>, typeck_results: &ty::TypeckResults<'_>, expr: &Expr<'_>) -> bool {
-    if macro_backtrace(expr.span).last().map_or(false, |macro_call| {
+    if macro_backtrace(expr.span).last().is_some_and(|macro_call| {
         is_panic(cx, macro_call.def_id) || cx.tcx.item_name(macro_call.def_id) == sym::unreachable
     }) {
         return false;

clippy_lints/src/bool_assert_comparison.rs

@@ -60,8 +60,8 @@ fn is_impl_not_trait_with_bool_out<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -
                 trait_id,
             )
         })
-        .map_or(false, |assoc_item| {
-            let proj = Ty::new_projection_from_args(cx.tcx, assoc_item.def_id, cx.tcx.mk_args_trait(ty, []));
+        .is_some_and(|assoc_item| {
+            let proj = Ty::new_projection(cx.tcx, assoc_item.def_id, cx.tcx.mk_args_trait(ty, []));
             let nty = cx.tcx.normalize_erasing_regions(cx.param_env, proj);
 
             nty.is_bool()

clippy_lints/src/booleans.rs

@@ -667,5 +667,5 @@ fn implements_ord(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
     let ty = cx.typeck_results().expr_ty(expr);
     cx.tcx
         .get_diagnostic_item(sym::Ord)
-        .map_or(false, |id| implements_trait(cx, ty, id, &[]))
+        .is_some_and(|id| implements_trait(cx, ty, id, &[]))
 }

clippy_lints/src/box_default.rs

@@ -45,7 +45,7 @@ impl LateLintPass<'_> for BoxDefault {
             // And that method is `new`
             && seg.ident.name == sym::new
             // And the call is that of a `Box` method
-            && path_def_id(cx, ty).map_or(false, |id| Some(id) == cx.tcx.lang_items().owned_box())
+            && path_def_id(cx, ty).is_some_and(|id| Some(id) == cx.tcx.lang_items().owned_box())
             // And the single argument to the call is another function call
             // This is the `T::default()` (or default equivalent) of `Box::new(T::default())`
             && let ExprKind::Call(arg_path, _) = arg.kind
@@ -83,9 +83,9 @@ fn is_plain_default(cx: &LateContext<'_>, arg_path: &Expr<'_>) -> bool {
 }
 
 fn is_local_vec_expn(cx: &LateContext<'_>, expr: &Expr<'_>, ref_expr: &Expr<'_>) -> bool {
-    macro_backtrace(expr.span).next().map_or(false, |call| {
-        cx.tcx.is_diagnostic_item(sym::vec_macro, call.def_id) && call.span.eq_ctxt(ref_expr.span)
-    })
+    macro_backtrace(expr.span)
+        .next()
+        .is_some_and(|call| cx.tcx.is_diagnostic_item(sym::vec_macro, call.def_id) && call.span.eq_ctxt(ref_expr.span))
 }
 
 #[derive(Default)]

clippy_lints/src/casts/unnecessary_cast.rs

@@ -159,8 +159,7 @@ pub(super) fn check<'tcx>(
         // The same is true if the expression encompassing the cast expression is a unary
         // expression or an addressof expression.
         let needs_block = matches!(cast_expr.kind, ExprKind::Unary(..) | ExprKind::AddrOf(..))
-            || get_parent_expr(cx, expr)
-                .map_or(false, |e| matches!(e.kind, ExprKind::Unary(..) | ExprKind::AddrOf(..)));
+            || get_parent_expr(cx, expr).is_some_and(|e| matches!(e.kind, ExprKind::Unary(..) | ExprKind::AddrOf(..)));
 
         span_lint_and_sugg(
             cx,

clippy_lints/src/comparison_chain.rs

@@ -110,7 +110,7 @@ impl<'tcx> LateLintPass<'tcx> for ComparisonChain {
                 let is_ord = cx
                     .tcx
                     .get_diagnostic_item(sym::Ord)
-                    .map_or(false, |id| implements_trait(cx, ty, id, &[]));
+                    .is_some_and(|id| implements_trait(cx, ty, id, &[]));
 
                 if !is_ord {
                     return;

clippy_lints/src/copies.rs

@@ -345,7 +345,7 @@ fn eq_binding_names(s: &Stmt<'_>, names: &[(HirId, Symbol)]) -> bool {
         let mut i = 0usize;
         let mut res = true;
         l.pat.each_binding_or_first(&mut |_, _, _, name| {
-            if names.get(i).map_or(false, |&(_, n)| n == name.name) {
+            if names.get(i).is_some_and(|&(_, n)| n == name.name) {
                 i += 1;
             } else {
                 res = false;
@@ -389,12 +389,10 @@ fn eq_stmts(
         let new_bindings = &moved_bindings[old_count..];
         blocks
             .iter()
-            .all(|b| get_stmt(b).map_or(false, |s| eq_binding_names(s, new_bindings)))
+            .all(|b| get_stmt(b).is_some_and(|s| eq_binding_names(s, new_bindings)))
     } else {
         true
-    }) && blocks
-        .iter()
-        .all(|b| get_stmt(b).map_or(false, |s| eq.eq_stmt(s, stmt)))
+    }) && blocks.iter().all(|b| get_stmt(b).is_some_and(|s| eq.eq_stmt(s, stmt)))
 }
 
 #[expect(clippy::too_many_lines)]
@@ -451,9 +449,7 @@ fn scan_block_for_eq<'tcx>(
     //     x + 50
     let expr_hash_eq = if let Some(e) = block.expr {
         let hash = hash_expr(cx, e);
-        blocks
-            .iter()
-            .all(|b| b.expr.map_or(false, |e| hash_expr(cx, e) == hash))
+        blocks.iter().all(|b| b.expr.is_some_and(|e| hash_expr(cx, e) == hash))
     } else {
         blocks.iter().all(|b| b.expr.is_none())
     };
@@ -514,7 +510,7 @@ fn scan_block_for_eq<'tcx>(
         });
     if let Some(e) = block.expr {
         for block in blocks {
-            if block.expr.map_or(false, |expr| !eq.eq_expr(expr, e)) {
+            if block.expr.is_some_and(|expr| !eq.eq_expr(expr, e)) {
                 moved_locals.truncate(moved_locals_at_start);
                 return BlockEq {
                     start_end_eq,
@@ -533,7 +529,7 @@ fn scan_block_for_eq<'tcx>(
 }
 
 fn check_for_warn_of_moved_symbol(cx: &LateContext<'_>, symbols: &[(HirId, Symbol)], if_expr: &Expr<'_>) -> bool {
-    get_enclosing_block(cx, if_expr.hir_id).map_or(false, |block| {
+    get_enclosing_block(cx, if_expr.hir_id).is_some_and(|block| {
         let ignore_span = block.span.shrink_to_lo().to(if_expr.span);
 
         symbols

clippy_lints/src/declared_lints.rs

@@ -481,6 +481,7 @@ pub static LINTS: &[&crate::LintInfo] = &[
     crate::methods::UNNECESSARY_JOIN_INFO,
     crate::methods::UNNECESSARY_LAZY_EVALUATIONS_INFO,
     crate::methods::UNNECESSARY_LITERAL_UNWRAP_INFO,
+    crate::methods::UNNECESSARY_MAP_OR_INFO,
     crate::methods::UNNECESSARY_MIN_OR_MAX_INFO,
     crate::methods::UNNECESSARY_RESULT_MAP_OR_ELSE_INFO,
     crate::methods::UNNECESSARY_SORT_BY_INFO,

clippy_lints/src/default_numeric_fallback.rs

@@ -253,6 +253,6 @@ impl<'tcx> From<Ty<'tcx>> for ExplicitTyBound {
 
 impl<'tcx> From<Option<Ty<'tcx>>> for ExplicitTyBound {
     fn from(v: Option<Ty<'tcx>>) -> Self {
-        Self(v.map_or(false, Ty::is_numeric))
+        Self(v.is_some_and(Ty::is_numeric))
     }
 }

clippy_lints/src/derivable_impls.rs

@@ -81,7 +81,7 @@ fn is_path_self(e: &Expr<'_>) -> bool {
 fn contains_trait_object(ty: Ty<'_>) -> bool {
     match ty.kind() {
         ty::Ref(_, ty, _) => contains_trait_object(*ty),
-        ty::Adt(def, args) => def.is_box() && args[0].as_type().map_or(false, contains_trait_object),
+        ty::Adt(def, args) => def.is_box() && args[0].as_type().is_some_and(contains_trait_object),
         ty::Dynamic(..) => true,
         _ => false,
     }

clippy_lints/src/derive.rs

@@ -327,7 +327,7 @@ fn check_copy_clone<'tcx>(cx: &LateContext<'tcx>, item: &Item<'_>, trait_ref: &h
     // there's a Copy impl for any instance of the adt.
     if !is_copy(cx, ty) {
         if ty_subs.non_erasable_generics().next().is_some() {
-            let has_copy_impl = cx.tcx.all_local_trait_impls(()).get(&copy_id).map_or(false, |impls| {
+            let has_copy_impl = cx.tcx.all_local_trait_impls(()).get(&copy_id).is_some_and(|impls| {
                 impls.iter().any(|&id| {
                     matches!(cx.tcx.type_of(id).instantiate_identity().kind(), ty::Adt(adt, _)
                                         if ty_adt.did() == adt.did())

clippy_lints/src/doc/missing_headers.rs

@@ -47,7 +47,7 @@ pub fn check(
         ),
         _ => (),
     }
-    if !headers.panics && panic_info.map_or(false, |el| !el.1) {
+    if !headers.panics && panic_info.is_some_and(|el| !el.1) {
         span_lint_and_note(
             cx,
             MISSING_PANICS_DOC,

clippy_lints/src/drop_forget_ref.rs

@@ -112,7 +112,7 @@ impl<'tcx> LateLintPass<'tcx> for DropForgetRef {
                             MEM_FORGET,
                             Cow::Owned(format!(
                                 "usage of `mem::forget` on {}",
-                                if arg_ty.ty_adt_def().map_or(false, |def| def.has_dtor(cx.tcx)) {
+                                if arg_ty.ty_adt_def().is_some_and(|def| def.has_dtor(cx.tcx)) {
                                     "`Drop` type"
                                 } else {
                                     "type with `Drop` fields"

clippy_lints/src/eta_reduction.rs

@@ -196,7 +196,7 @@ fn check_clousure<'tcx>(cx: &LateContext<'tcx>, outer_receiver: Option<&Expr<'tc
             {
                 span_lint_and_then(cx, REDUNDANT_CLOSURE, expr.span, "redundant closure", |diag| {
                     if let Some(mut snippet) = snippet_opt(cx, callee.span) {
-                        if path_to_local(callee).map_or(false, |l| {
+                        if path_to_local(callee).is_some_and(|l| {
                             // FIXME: Do we really need this `local_used_in` check?
                             // Isn't it checking something like... `callee(callee)`?
                             // If somehow this check is needed, add some test for it,

clippy_lints/src/functions/not_unsafe_ptr_arg_deref.rs

@@ -87,7 +87,7 @@ fn raw_ptr_arg(cx: &LateContext<'_>, arg: &hir::Param<'_>) -> Option<HirId> {
 }
 
 fn check_arg(cx: &LateContext<'_>, raw_ptrs: &HirIdSet, arg: &hir::Expr<'_>) {
-    if path_to_local(arg).map_or(false, |id| raw_ptrs.contains(&id)) {
+    if path_to_local(arg).is_some_and(|id| raw_ptrs.contains(&id)) {
         span_lint(
             cx,
             NOT_UNSAFE_PTR_ARG_DEREF,

clippy_lints/src/infinite_iter.rs

@@ -171,13 +171,13 @@ fn is_infinite(cx: &LateContext<'_>, expr: &Expr<'_>) -> Finiteness {
             if let ExprKind::Path(ref qpath) = path.kind {
                 cx.qpath_res(qpath, path.hir_id)
                     .opt_def_id()
-                    .map_or(false, |id| cx.tcx.is_diagnostic_item(sym::iter_repeat, id))
+                    .is_some_and(|id| cx.tcx.is_diagnostic_item(sym::iter_repeat, id))
                     .into()
             } else {
                 Finite
             }
         },
-        ExprKind::Struct(..) => higher::Range::hir(expr).map_or(false, |r| r.end.is_none()).into(),
+        ExprKind::Struct(..) => higher::Range::hir(expr).is_some_and(|r| r.end.is_none()).into(),
         _ => Finite,
     }
 }
@@ -228,9 +228,7 @@ fn complete_infinite_iter(cx: &LateContext<'_>, expr: &Expr<'_>) -> Finiteness {
                 let not_double_ended = cx
                     .tcx
                     .get_diagnostic_item(sym::DoubleEndedIterator)
-                    .map_or(false, |id| {
-                        !implements_trait(cx, cx.typeck_results().expr_ty(receiver), id, &[])
-                    });
+                    .is_some_and(|id| !implements_trait(cx, cx.typeck_results().expr_ty(receiver), id, &[]));
                 if not_double_ended {
                     return is_infinite(cx, receiver);
                 }

clippy_lints/src/item_name_repetitions.rs

@@ -309,8 +309,8 @@ fn check_enum_start(cx: &LateContext<'_>, item_name: &str, variant: &Variant<'_>
     let item_name_chars = item_name.chars().count();
 
     if count_match_start(item_name, name).char_count == item_name_chars
-        && name.chars().nth(item_name_chars).map_or(false, |c| !c.is_lowercase())
-        && name.chars().nth(item_name_chars + 1).map_or(false, |c| !c.is_numeric())
+        && name.chars().nth(item_name_chars).is_some_and(|c| !c.is_lowercase())
+        && name.chars().nth(item_name_chars + 1).is_some_and(|c| !c.is_numeric())
     {
         span_lint_hir(
             cx,

clippy_lints/src/iter_not_returning_iterator.rs

@@ -75,7 +75,7 @@ fn check_sig(cx: &LateContext<'_>, name: Symbol, sig: &FnSig<'_>, fn_id: LocalDe
         if cx
             .tcx
             .get_diagnostic_item(sym::Iterator)
-            .map_or(false, |iter_id| !implements_trait(cx, ret_ty, iter_id, &[]))
+            .is_some_and(|iter_id| !implements_trait(cx, ret_ty, iter_id, &[]))
         {
             span_lint(
                 cx,

clippy_lints/src/len_zero.rs

@@ -622,7 +622,7 @@ fn has_is_empty(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
 
     let ty = &cx.typeck_results().expr_ty(expr).peel_refs();
     match ty.kind() {
-        ty::Dynamic(tt, ..) => tt.principal().map_or(false, |principal| {
+        ty::Dynamic(tt, ..) => tt.principal().is_some_and(|principal| {
             let is_empty = sym!(is_empty);
             cx.tcx
                 .associated_items(principal.def_id())

clippy_lints/src/lifetimes.rs

@@ -737,7 +737,7 @@ fn elision_suggestions(
     suggestions.extend(
         usages
             .iter()
-            .filter(|usage| named_lifetime(usage).map_or(false, |id| elidable_lts.contains(&id)))
+            .filter(|usage| named_lifetime(usage).is_some_and(|id| elidable_lts.contains(&id)))
             .map(|usage| {
                 match cx.tcx.parent_hir_node(usage.hir_id) {
                     Node::Ty(Ty {

clippy_lints/src/loops/manual_find.rs

@@ -58,7 +58,7 @@ pub(super) fn check<'tcx>(
             .tcx
             .lang_items()
             .copy_trait()
-            .map_or(false, |id| implements_trait(cx, ty, id, &[]))
+            .is_some_and(|id| implements_trait(cx, ty, id, &[]))
         {
             snippet.push_str(
                 &format!(

clippy_lints/src/loops/manual_memcpy.rs

@@ -416,7 +416,7 @@ fn get_assignments<'a, 'tcx>(
         .chain(*expr)
         .filter(move |e| {
             if let ExprKind::AssignOp(_, place, _) = e.kind {
-                path_to_local(place).map_or(false, |id| {
+                path_to_local(place).is_some_and(|id| {
                     !loop_counters
                         .iter()
                         // skip the first item which should be `StartKind::Range`

clippy_lints/src/loops/mut_range_bound.rs

@@ -126,7 +126,7 @@ impl BreakAfterExprVisitor {
             break_after_expr: false,
         };
 
-        get_enclosing_block(cx, hir_id).map_or(false, |block| {
+        get_enclosing_block(cx, hir_id).is_some_and(|block| {
             visitor.visit_block(block);
             visitor.break_after_expr
         })

clippy_lints/src/loops/same_item_push.rs

@@ -50,7 +50,7 @@ pub(super) fn check<'tcx>(
             .tcx
             .lang_items()
             .clone_trait()
-            .map_or(false, |id| implements_trait(cx, ty, id, &[]))
+            .is_some_and(|id| implements_trait(cx, ty, id, &[]))
     {
         // Make sure that the push does not involve possibly mutating values
         match pushed_item.kind {

clippy_lints/src/loops/utils.rs

@@ -256,9 +256,10 @@ fn is_conditional(expr: &Expr<'_>) -> bool {
 /// If `arg` was the argument to a `for` loop, return the "cleanest" way of writing the
 /// actual `Iterator` that the loop uses.
 pub(super) fn make_iterator_snippet(cx: &LateContext<'_>, arg: &Expr<'_>, applic_ref: &mut Applicability) -> String {
-    let impls_iterator = cx.tcx.get_diagnostic_item(sym::Iterator).map_or(false, |id| {
-        implements_trait(cx, cx.typeck_results().expr_ty(arg), id, &[])
-    });
+    let impls_iterator = cx
+        .tcx
+        .get_diagnostic_item(sym::Iterator)
+        .is_some_and(|id| implements_trait(cx, cx.typeck_results().expr_ty(arg), id, &[]));
     if impls_iterator {
         format!(
             "{}",

clippy_lints/src/manual_clamp.rs

@@ -226,7 +226,7 @@ impl TypeClampability {
         } else if cx
             .tcx
             .get_diagnostic_item(sym::Ord)
-            .map_or(false, |id| implements_trait(cx, ty, id, &[]))
+            .is_some_and(|id| implements_trait(cx, ty, id, &[]))
         {
             Some(TypeClampability::Ord)
         } else {

clippy_lints/src/manual_strip.rs

@@ -162,9 +162,9 @@ fn eq_pattern_length<'tcx>(cx: &LateContext<'tcx>, pattern: &Expr<'_>, expr: &'t
         ..
     }) = expr.kind
     {
-        constant_length(cx, pattern).map_or(false, |length| *n == length)
+        constant_length(cx, pattern).is_some_and(|length| *n == length)
     } else {
-        len_arg(cx, expr).map_or(false, |arg| eq_expr_value(cx, pattern, arg))
+        len_arg(cx, expr).is_some_and(|arg| eq_expr_value(cx, pattern, arg))
     }
 }
 

clippy_lints/src/matches/match_like_matches.rs

@@ -74,7 +74,7 @@ where
         && b0 != b1
         && (first_guard.is_none() || iter.len() == 0)
         && first_attrs.is_empty()
-        && iter.all(|arm| find_bool_lit(&arm.2.kind).map_or(false, |b| b == b0) && arm.3.is_none() && arm.0.is_empty())
+        && iter.all(|arm| find_bool_lit(&arm.2.kind).is_some_and(|b| b == b0) && arm.3.is_none() && arm.0.is_empty())
     {
         if let Some(last_pat) = last_pat_opt {
             if !is_wild(last_pat) {

clippy_lints/src/matches/redundant_pattern_match.rs

@@ -447,7 +447,7 @@ fn is_pat_variant(cx: &LateContext<'_>, pat: &Pat<'_>, path: &QPath<'_>, expecte
             .tcx
             .lang_items()
             .get(expected_lang_item)
-            .map_or(false, |expected_id| cx.tcx.parent(id) == expected_id),
+            .is_some_and(|expected_id| cx.tcx.parent(id) == expected_id),
         Item::Diag(expected_ty, expected_variant) => {
             let ty = cx.typeck_results().pat_ty(pat);
 

clippy_lints/src/matches/single_match.rs

@@ -175,7 +175,7 @@ impl<'tcx> Visitor<'tcx> for PatVisitor<'tcx> {
         if matches!(pat.kind, PatKind::Binding(..)) {
             ControlFlow::Break(())
         } else {
-            self.has_enum |= self.typeck.pat_ty(pat).ty_adt_def().map_or(false, AdtDef::is_enum);
+            self.has_enum |= self.typeck.pat_ty(pat).ty_adt_def().is_some_and(AdtDef::is_enum);
             walk_pat(self, pat)
         }
     }

clippy_lints/src/matches/try_err.rs

@@ -58,7 +58,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, scrutine
                 let span = hygiene::walk_chain(err_arg.span, try_arg.span.ctxt());
                 let mut applicability = Applicability::MachineApplicable;
                 let origin_snippet = snippet_with_applicability(cx, span, "_", &mut applicability);
-                let ret_prefix = if get_parent_expr(cx, expr).map_or(false, |e| matches!(e.kind, ExprKind::Ret(_))) {
+                let ret_prefix = if get_parent_expr(cx, expr).is_some_and(|e| matches!(e.kind, ExprKind::Ret(_))) {
                     "" // already returns
                 } else {
                     "return "