Mark result of appendExtraQueryExclusions as Readonly to prevent further modification

Author: mbg

lib/analyze-action-post.js

@@ -1489,14 +1489,15 @@ export function generateCodeScanningConfig(
 export function appendExtraQueryExclusions(
   extraQueryExclusions: ExcludeQueryFilter[],
   cliConfig: UserConfig,
-): UserConfig {
+): Readonly<UserConfig> {
+  // make a copy so we can modify it and so that modifications to the input
+  // object do not affect the result that is marked as `Readonly`.
+  const augmentedConfig = cloneObject(cliConfig);
+
   if (extraQueryExclusions.length === 0) {
-    return cliConfig;
+    return augmentedConfig;
   }
 
-  // make a copy so we can modify it
-  const augmentedConfig = cloneObject(cliConfig);
-
   augmentedConfig["query-filters"] = [
     // Ordering matters. If the first filter is an inclusion, it implicitly
     // excludes all queries that are not included. If it is an exclusion,