Add identity expansion checking

1 files changed, 30 insertions, 0 deletions

diff --git a/crates/ra_ide/src/diagnostics.rs b/crates/ra_ide/src/diagnostics.rs
index a10e642db..50106e31e 100644
--- a/crates/ra_ide/src/diagnostics.rs
+++ b/crates/ra_ide/src/diagnostics.rs
@@ -715,4 +715,34 @@ fn main() {
             check_struct_shorthand_initialization,
         );
     }
+
+    #[test]
+    fn test_bad_macro_stackover() {
+        check_no_diagnostic(
+            r#"
+                //- /main.rs
+    #[macro_export]
+    macro_rules! match_ast {
+        (match $node:ident { $($tt:tt)* }) => { match_ast!(match ($node) { $($tt)* }) };
+
+        (match ($node:expr) {
+            $( ast::$ast:ident($it:ident) => $res:expr, )*
+            _ => $catch_all:expr $(,)?
+        }) => {{
+            $( if let Some($it) = ast::$ast::cast($node.clone()) { $res } else )*
+            { $catch_all }
+        }};
+    }
+
+    fn main() {
+        let anchor = match_ast! {
+            match parent {
+                as => {},
+                _ => return None
+            }
+        };
+    }
+            "#,
+        );
+    }
 }