check for presence of partialeq on linted types

Author: Jacherr

clippy_lints/src/methods/unnecessary_map_or.rs

@@ -5,7 +5,7 @@ use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::eager_or_lazy::switch_to_eager_eval;
 use clippy_utils::source::snippet_opt;
 use clippy_utils::sugg::{Sugg, make_binop};
-use clippy_utils::ty::get_type_diagnostic_name;
+use clippy_utils::ty::{get_type_diagnostic_name, implements_trait};
 use clippy_utils::visitors::is_local_used;
 use clippy_utils::{is_from_proc_macro, path_to_local_id};
 use rustc_ast::LitKind::Bool;
@@ -80,6 +80,8 @@ pub(super) fn check<'a>(
             && !is_local_used(cx, non_binding_location, hir_id)
             && let typeck_results = cx.typeck_results()
             && typeck_results.expr_ty(l) == typeck_results.expr_ty(r)
+            && let Some(partial_eq) = cx.tcx.get_diagnostic_item(sym::PartialEq)
+            && implements_trait(cx, recv_ty, partial_eq, &[recv_ty.into()])
     {
         let wrap = variant.variant_name();
 

tests/ui/unnecessary_map_or.fixed

@@ -45,6 +45,11 @@ fn main() {
     with_span! {
         let _ = Some(5).map_or(false, |n| n == 5);
     }
+
+    // check for presence of PartialEq, and alter suggestion to use `is_ok_and` if absent
+    struct S;
+    let r: Result<i32, S> = Ok(3);
+    let _ = r.is_ok_and(|x| x == 7);
 }
 
 #[clippy::msrv = "1.69.0"]

tests/ui/unnecessary_map_or.rs

@@ -48,6 +48,11 @@ fn main() {
     with_span! {
         let _ = Some(5).map_or(false, |n| n == 5);
     }
+
+    // check for presence of PartialEq, and alter suggestion to use `is_ok_and` if absent
+    struct S;
+    let r: Result<i32, S> = Ok(3);
+    let _ = r.map_or(false, |x| x == 7);
 }
 
 #[clippy::msrv = "1.69.0"]

tests/ui/unnecessary_map_or.stderr

@@ -83,5 +83,11 @@ error: this `map_or` is redundant
 LL |     let _ = Some(5).map_or(false, |n| n == 5).then(|| 1);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use a standard comparison instead: `(Some(5) == Some(5))`
 
-error: aborting due to 11 previous errors
+error: this `map_or` is redundant
+  --> tests/ui/unnecessary_map_or.rs:55:13
+   |
+LL |     let _ = r.map_or(false, |x| x == 7);
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use is_ok_and instead: `r.is_ok_and(|x| x == 7)`
+
+error: aborting due to 12 previous errors