util: preserve function names without source map names

Signed-off-by: Hiroki Osame <hiroki.osame@gmail.com>
PR-URL: https://github.com/nodejs/node/pull/65108
Fixes: https://github.com/nodejs/node/issues/65104
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Aviv Keller <me@aviv.sh>
Reviewed-By: Marco Ippolito <marcoippolito54@gmail.com>
Signed-off-by: Juan José Arboleda <soyjuanarbol@gmail.com>

lib/util.js

@@ -537,8 +537,7 @@ function reconstructCallSite(callSite) {
   if (!entry?.originalSource) return;
   return {
     __proto__: null,
-    // If the name is not found, it is an empty string to match the behavior of `util.getCallSite()`
-    functionName: entry.name ?? '',
+    functionName: entry.name || callSite.functionName,
     scriptName: entry.originalSource,
     lineNumber: entry.originalLine + 1,
     column: entry.originalColumn + 1,

test/fixtures/source-map/get-call-sites-function-name-mapped.js

@@ -0,0 +1,2 @@
+const{getCallSites}=require('node:util');function foo(){process.stdout.write(JSON.stringify(getCallSites({sourceMap:true})[0]))}foo();
+//# sourceMappingURL=get-call-sites-function-name-mapped.map

test/fixtures/source-map/get-call-sites-function-name-mapped.map

@@ -0,0 +1,7 @@
+{
+  "version": 3,
+  "sources": ["get-call-sites-function-name-original.js"],
+  "sourcesContent": ["const { getCallSites } = require('node:util'); function foo() { process.stdout.write(JSON.stringify(getCallSites({ sourceMap: true })[0])); } foo();"],
+  "mappings": "AAAA,KAAM,CAAE,YAAa,EAAI,QAAQ,WAAW,EAAG,SAAS,KAAM,CAAE,QAAQ,OAAO,MAAM,KAAK,UAAU,aAAa,CAAE,UAAW,EAAK,CAAC,EAAE,CAAC,CAAC,CAAC,CAAG,CAAE,IAAI",
+  "names": []
+}