improve diagnostics

Author: ada4a

clippy_lints/src/matches/match_as_ref.rs

@@ -1,4 +1,4 @@
-use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::res::{MaybeDef, MaybeQPath};
 use clippy_utils::source::snippet_with_applicability;
 use clippy_utils::ty::option_arg_ty;
@@ -41,17 +41,22 @@ pub(crate) fn check(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>], expr:
         };
 
         let mut applicability = Applicability::MachineApplicable;
-        span_lint_and_sugg(
+        span_lint_and_then(
             cx,
             MATCH_AS_REF,
             expr.span,
-            format!("use `{method}()` instead"),
-            "try",
-            format!(
-                "{}.{method}(){cast}",
-                snippet_with_applicability(cx, ex.span, "_", &mut applicability),
-            ),
-            applicability,
+            format!("manual implementation of `Option::{method}`"),
+            |diag| {
+                diag.span_suggestion_verbose(
+                    expr.span,
+                    format!("use `Option::{method}()` directly"),
+                    format!(
+                        "{}.{method}(){cast}",
+                        snippet_with_applicability(cx, ex.span, "_", &mut applicability),
+                    ),
+                    applicability,
+                );
+            },
         );
     }
 }

tests/ui/match_as_ref.stderr

@@ -1,4 +1,4 @@
-error: use `as_ref()` instead
+error: manual implementation of `Option::as_ref`
   --> tests/ui/match_as_ref.rs:6:33
    |
 LL |       let borrowed: Option<&()> = match owned {
@@ -7,12 +7,21 @@ LL | |
 LL | |         None => None,
 LL | |         Some(ref v) => Some(v),
 LL | |     };
-   | |_____^ help: try: `owned.as_ref()`
+   | |_____^
    |
    = note: `-D clippy::match-as-ref` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::match_as_ref)]`
+help: use `Option::as_ref()` directly
+   |
+LL -     let borrowed: Option<&()> = match owned {
+LL -
+LL -         None => None,
+LL -         Some(ref v) => Some(v),
+LL -     };
+LL +     let borrowed: Option<&()> = owned.as_ref();
+   |
 
-error: use `as_mut()` instead
+error: manual implementation of `Option::as_mut`
   --> tests/ui/match_as_ref.rs:13:39
    |
 LL |       let borrow_mut: Option<&mut ()> = match mut_owned {
@@ -21,17 +30,37 @@ LL | |
 LL | |         None => None,
 LL | |         Some(ref mut v) => Some(v),
 LL | |     };
-   | |_____^ help: try: `mut_owned.as_mut()`
+   | |_____^
+   |
+help: use `Option::as_mut()` directly
+   |
+LL -     let borrow_mut: Option<&mut ()> = match mut_owned {
+LL -
+LL -         None => None,
+LL -         Some(ref mut v) => Some(v),
+LL -     };
+LL +     let borrow_mut: Option<&mut ()> = mut_owned.as_mut();
+   |
 
-error: use `as_ref()` instead
+error: manual implementation of `Option::as_ref`
   --> tests/ui/match_as_ref.rs:32:13
    |
 LL | /             match self.source {
 LL | |
 LL | |                 Some(ref s) => Some(s),
 LL | |                 None => None,
 LL | |             }
-   | |_____________^ help: try: `self.source.as_ref().map(|x| x as _)`
+   | |_____________^
+   |
+help: use `Option::as_ref()` directly
+   |
+LL -             match self.source {
+LL -
+LL -                 Some(ref s) => Some(s),
+LL -                 None => None,
+LL -             }
+LL +             self.source.as_ref().map(|x| x as _)
+   |
 
 error: aborting due to 3 previous errors