chore: use multipart_suggestions for match_same_arms (#13803)

This addresses #13099 for
the match_same_arms lint.

changelog: [match_same_arms]: Updated match_same_arms to use
multipart_suggestions where appropriate

clippy_lints/src/matches/match_same_arms.rs

@@ -74,8 +74,8 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, arms: &'tcx [Arm<'_>]) {
                         // check if using the same bindings as before
                         HirIdMapEntry::Occupied(entry) => return *entry.get() == b_id,
                     }
-                // the names technically don't have to match; this makes the lint more conservative
-                && cx.tcx.hir().name(a_id) == cx.tcx.hir().name(b_id)
+                    // the names technically don't have to match; this makes the lint more conservative
+                    && cx.tcx.hir().name(a_id) == cx.tcx.hir().name(b_id)
                     && cx.typeck_results().expr_ty(a) == cx.typeck_results().expr_ty(b)
                     && pat_contains_local(lhs.pat, a_id)
                     && pat_contains_local(rhs.pat, b_id)
@@ -149,16 +149,12 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, arms: &'tcx [Arm<'_>]) {
                     let move_pat_snip = snippet_with_applicability(cx, move_arm.pat.span, "<pat2>", &mut appl);
                     let keep_pat_snip = snippet_with_applicability(cx, keep_arm.pat.span, "<pat1>", &mut appl);
 
-                    diag.span_suggestion(
-                        keep_arm.pat.span,
-                        "or try merging the arm patterns",
-                        format!("{keep_pat_snip} | {move_pat_snip}"),
-                        appl,
-                    )
-                    .span_suggestion(
-                        adjusted_arm_span(cx, move_arm.span),
-                        "and remove this obsolete arm",
-                        "",
+                    diag.multipart_suggestion(
+                        "or try merging the arm patterns and removing the obsolete arm",
+                        vec![
+                            (keep_arm.pat.span, format!("{keep_pat_snip} | {move_pat_snip}")),
+                            (adjusted_arm_span(cx, move_arm.span), String::new()),
+                        ],
                         appl,
                     )
                     .help("try changing either arm body");

tests/ui/match_same_arms.stderr

@@ -20,13 +20,10 @@ LL |         (1, .., 3) => 42,
    |         ^^^^^^^^^^^^^^^^
    |
    = help: try changing either arm body
-help: or try merging the arm patterns
+help: or try merging the arm patterns and removing the obsolete arm
    |
-LL |         (1, .., 3) | (.., 3) => 42,
-   |         ~~~~~~~~~~~~~~~~~~~~
-help: and remove this obsolete arm
-   |
-LL -         (.., 3) => 42,
+LL ~         (1, .., 3) | (.., 3) => 42,
+LL ~         _ => 0,
    |
 
 error: this match arm has an identical body to another arm
@@ -36,13 +33,11 @@ LL |         51 => 1,
    |         ^^^^^^^
    |
    = help: try changing either arm body
-help: or try merging the arm patterns
-   |
-LL |         51 | 42 => 1,
-   |         ~~~~~~~
-help: and remove this obsolete arm
+help: or try merging the arm patterns and removing the obsolete arm
    |
 LL -         42 => 1,
+LL -         51 => 1,
+LL +         51 | 42 => 1,
    |
 
 error: this match arm has an identical body to another arm
@@ -52,13 +47,10 @@ LL |         41 => 2,
    |         ^^^^^^^
    |
    = help: try changing either arm body
-help: or try merging the arm patterns
+help: or try merging the arm patterns and removing the obsolete arm
    |
-LL |         41 | 52 => 2,
-   |         ~~~~~~~
-help: and remove this obsolete arm
-   |
-LL -         52 => 2,
+LL ~         41 | 52 => 2,
+LL ~         _ => 0,
    |
 
 error: this match arm has an identical body to another arm
@@ -68,13 +60,11 @@ LL |         2 => 2,
    |         ^^^^^^
    |
    = help: try changing either arm body
-help: or try merging the arm patterns
-   |
-LL |         2 | 1 => 2,
-   |         ~~~~~
-help: and remove this obsolete arm
+help: or try merging the arm patterns and removing the obsolete arm
    |
 LL -         1 => 2,
+LL -         2 => 2,
+LL +         2 | 1 => 2,
    |
 
 error: this match arm has an identical body to another arm
@@ -84,13 +74,11 @@ LL |         3 => 2,
    |         ^^^^^^
    |
    = help: try changing either arm body
-help: or try merging the arm patterns
+help: or try merging the arm patterns and removing the obsolete arm
    |
-LL |         3 | 1 => 2,
-   |         ~~~~~
-help: and remove this obsolete arm
-   |
-LL -         1 => 2,
+LL ~         2 => 2,
+LL |
+LL ~         3 | 1 => 2,
    |
 
 error: this match arm has an identical body to another arm
@@ -100,14 +88,11 @@ LL |         2 => 2,
    |         ^^^^^^
    |
    = help: try changing either arm body
-help: or try merging the arm patterns
+help: or try merging the arm patterns and removing the obsolete arm
    |
-LL |         2 | 3 => 2,
-   |         ~~~~~
-help: and remove this obsolete arm
-   |
-LL -         3 => 2,
-LL +
+LL ~         2 | 3 => 2,
+LL |
+LL ~
    |
 
 error: this match arm has an identical body to another arm
@@ -117,13 +102,11 @@ LL |                 CommandInfo::External { name, .. } => name.to_string(),
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: try changing either arm body
-help: or try merging the arm patterns
-   |
-LL |                 CommandInfo::External { name, .. } | CommandInfo::BuiltIn { name, .. } => name.to_string(),
-   |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-help: and remove this obsolete arm
+help: or try merging the arm patterns and removing the obsolete arm
    |
 LL -                 CommandInfo::BuiltIn { name, .. } => name.to_string(),
+LL -                 CommandInfo::External { name, .. } => name.to_string(),
+LL +                 CommandInfo::External { name, .. } | CommandInfo::BuiltIn { name, .. } => name.to_string(),
    |
 
 error: aborting due to 8 previous errors