remove both parens in ((x))

Author: ada4a

clippy_lints/src/double_parens.rs

@@ -43,8 +43,13 @@ declare_lint_pass!(DoubleParens => [DOUBLE_PARENS]);
 impl EarlyLintPass for DoubleParens {
     fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
         let (outer_span, inner_span) = match &expr.kind {
-            ExprKind::Paren(in_paren) if matches!(in_paren.kind, ExprKind::Paren(_) | ExprKind::Tup(_)) => {
-                (expr.span, in_paren.span)
+            ExprKind::Paren(in_paren) => {
+                let inner_span = match &in_paren.kind {
+                    ExprKind::Paren(inner) => inner.span,
+                    ExprKind::Tup(_) => in_paren.span,
+                    _ => return,
+                };
+                (expr.span, inner_span)
             },
             ExprKind::Call(_, params)
                 if let [param] = &**params

tests/ui/double_parens.fixed

@@ -12,7 +12,7 @@ impl DummyStruct {
 }
 
 fn simple_double_parens() -> i32 {
-    (0)
+    0
     //~^ double_parens
 }
 

tests/ui/double_parens.stderr

@@ -2,7 +2,7 @@ error: unnecessary parentheses
   --> tests/ui/double_parens.rs:15:5
    |
 LL |     ((0))
-   |     ^^^^^ help: remove them: `(0)`
+   |     ^^^^^ help: remove them: `0`
    |
    = note: `-D clippy::double-parens` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::double_parens)]`