Only treat plain literal patterns as short

Author: oli-obk

src/tools/rustfmt/src/patterns.rs

@@ -37,12 +37,20 @@ pub(crate) fn is_short_pattern(pat: &ast::Pat, pat_str: &str) -> bool {
 }
 
 fn is_short_pattern_inner(pat: &ast::Pat) -> bool {
-    match pat.kind {
-        ast::PatKind::Rest
-        | ast::PatKind::Never
-        | ast::PatKind::Wild
-        | ast::PatKind::Err(_)
-        | ast::PatKind::Lit(_) => true,
+    match &pat.kind {
+        ast::PatKind::Rest | ast::PatKind::Never | ast::PatKind::Wild | ast::PatKind::Err(_) => {
+            true
+        }
+        ast::PatKind::Lit(expr) => match &expr.kind {
+            ast::ExprKind::Lit(_) => true,
+            ast::ExprKind::Unary(ast::UnOp::Neg, expr) => match &expr.kind {
+                ast::ExprKind::Lit(_) => true,
+                _ => unreachable!(),
+            },
+            ast::ExprKind::ConstBlock(_) => false,
+            ast::ExprKind::Path(..) => false,
+            _ => unreachable!(),
+        },
         ast::PatKind::Ident(_, _, ref pat) => pat.is_none(),
         ast::PatKind::Struct(..)
         | ast::PatKind::MacCall(..)

src/tools/rustfmt/tests/source/pattern.rs

@@ -88,3 +88,13 @@ fn issue3728() {
         | c;
     foo((1,));
 }
+
+fn literals() {
+    match 42 {
+        const { 1 + 2 } | 4
+        | 6 => {}
+        10 | 11 | 12
+        | 13 | 14 => {}
+        _ => {}
+    }
+}

src/tools/rustfmt/tests/target/pattern.rs

@@ -96,3 +96,11 @@ fn issue3728() {
     let foo = |(c,)| c;
     foo((1,));
 }
+
+fn literals() {
+    match 42 {
+        const { 1 + 2 } | 4 | 6 => {}
+        10 | 11 | 12 | 13 | 14 => {}
+        _ => {}
+    }
+}