We really want to only use declared variables in our JavaScript code

Author: matthiask

biome.json

@@ -15,15 +15,17 @@
         "enabled": true,
         "rules": {
             "recommended": true,
+            "correctness": {
+                "noUndeclaredVariables": "error"
+            },
             "suspicious": {
                 "noDocumentCookie": "off"
             }
         }
     },
     "javascript": {
         "formatter": {
-            "trailingCommas": "es5",
-            "quoteStyle": "double"
+            "trailingCommas": "es5"
         }
     }
 }