From 10d2cf94cfede5c7814af916a5bdac19f07cb987 Mon Sep 17 00:00:00 2001
From: Michael Ficarra <mficarra@shapesecurity.com>
Date: Thu, 20 Jun 2024 12:38:28 -0600
Subject: [PATCH] use a special warning message for @@ notation

---
 src/lint/collect-header-diagnostics.ts | 9 ++++++---
 test/lint.js                           | 2 +-
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/lint/collect-header-diagnostics.ts b/src/lint/collect-header-diagnostics.ts
index f786833d..d276ca80 100644
--- a/src/lint/collect-header-diagnostics.ts
+++ b/src/lint/collect-header-diagnostics.ts
@@ -58,12 +58,15 @@ export function collectHeaderDiagnostics(
 
     if (!nameMatches) {
       const { line, column } = offsetToLineAndColumn(contents, 0);
+      let message = `expected operation to have a name like 'Example', 'Runtime Semantics: Foo', 'Example.prop', etc, but found ${JSON.stringify(name)}`;
+      let oldSymbolMatch = name.match(/@@([a-z][a-zA-Z]+)/);
+      if (oldSymbolMatch != null) {
+        message = `found use of unsupported legacy well-known Symbol notation ${oldSymbolMatch[0]}; use %Symbol.${oldSymbolMatch[1]}% instead`;
+      }
       report({
         type: 'contents',
         ruleId,
-        message: `expected operation to have a name like 'Example', 'Runtime Semantics: Foo', 'Example.prop', etc, but found ${JSON.stringify(
-          name,
-        )}`,
+        message,
         node: element,
         nodeRelativeLine: line,
         nodeRelativeColumn: column,
diff --git a/test/lint.js b/test/lint.js
index ad4d6dd0..5ef89cbb 100644
--- a/test/lint.js
+++ b/test/lint.js
@@ -299,7 +299,7 @@ describe('linting whole program', () => {
           ruleId: 'header-format',
           nodeType: 'h1',
           message:
-            "expected operation to have a name like 'Example', 'Runtime Semantics: Foo', 'Example.prop', etc, but found \"Example [ @@baz ] \"",
+            'found use of unsupported legacy well-known Symbol notation @@baz; use %Symbol.baz% instead',
         },
       );
     });