patch 8.2.2747: Vim9: not always an error for too many function arguments

Problem:    Vim9: not always an error for too many function arguments.
Solution:   Check for getting too many arguments.
diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
index c02a324..6b353dd 100644
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
@@ -2102,7 +2102,7 @@
   var lines =<< trim END
       vim9script
       var script = 'test'
-      assert_equal(['test'], map(['one'], () => script))
+      assert_equal(['test'], map(['one'], (_, _) => script))
   END
   CheckScriptSuccess(lines)
 enddef
@@ -2355,7 +2355,7 @@
         var x = ['a', 'b', 'c']
         if 1
           var y = 'x'
-          map(x, () => y)
+          map(x, (_, _) => y)
         endif
         var z = x
         assert_equal(['x', 'x', 'x'], z)
@@ -2654,6 +2654,17 @@
   CheckDefAndScriptFailure(lines, 'E1181:', 1)
 enddef
 
+def Test_too_many_arguments()
+  var lines =<< trim END
+    echo [0, 1, 2]->map(() => 123)
+  END
+  CheckDefExecAndScriptFailure(lines, 'E1106: 2 arguments too many', 1)
+
+  lines =<< trim END
+    echo [0, 1, 2]->map((_) => 123)
+  END
+  CheckDefExecAndScriptFailure(lines, 'E1106: One argument too many', 1)
+enddef
 
 
 " vim: ts=8 sw=2 sts=2 expandtab tw=80 fdm=marker