Suggest a list of possible arg labels when an argument is unlabelled (#6755)

Signed-off-by: Nick Cameron <nrc@ncameron.org>

src/lib/utils.ts

@@ -41,7 +41,9 @@ export async function refreshPage(method = 'UI button') {
  * Get all labels for a keyword call expression.
  */
 export function allLabels(callExpression: CallExpressionKw): string[] {
-  return callExpression.arguments.map((a) => a.label.name)
+  return callExpression.arguments
+    .map((a) => a.label?.name)
+    .filter((a) => a !== undefined)
 }
 
 /**