fix #49553

src/vs/base/node/config.ts

@@ -171,7 +171,7 @@ export class ConfigWatcher<T> implements IConfigWatcher<T>, IDisposable {
 			// Windows: in some cases the filename contains artifacts from the absolute path
 			// see https://github.com/nodejs/node/issues/19170
 			// As such, we have to ensure that the filename basename is used for comparison.
-			if (isWindows && filename !== this.configName) {
+			if (isWindows && filename && filename !== this.configName) {
 				filename = basename(filename);
 			}
 

src/vs/base/node/extfs.ts

@@ -620,7 +620,7 @@ function normalizePath(path: string): string {
 	return strings.rtrim(paths.normalize(path), paths.sep);
 }
 
-export function watch(path: string, onChange: (type: string, path: string) => void, onError: (error: string) => void): fs.FSWatcher {
+export function watch(path: string, onChange: (type: string, path?: string) => void, onError: (error: string) => void): fs.FSWatcher {
 	try {
 		const watcher = fs.watch(path);