vm_args.c: improve keyword argument errors

* vm_args.c (argument_arity_error): improve required keyword
  argument errors when non-keyword arguments given.
  [ruby-core:79439] [Bug #13196]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59259 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 13 insertions, 0 deletions

diff --git a/test/ruby/test_keyword.rb b/test/ruby/test_keyword.rb
index f10412e6cd..4c99a3212d 100644
--- a/test/ruby/test_keyword.rb
+++ b/test/ruby/test_keyword.rb
@@ -641,4 +641,17 @@ class TestKeywordArguments < Test::Unit::TestCase
     assert_equal(x, result)
     assert_kind_of(klass, result, bug12884)
   end
+
+  def test_arity_error_message
+    obj = Object.new
+    def obj.t(x:) end
+    assert_raise_with_message(ArgumentError, /required keyword: x\)/) do
+      obj.t(42)
+    end
+    obj = Object.new
+    def obj.t(x:, y:, z: nil) end
+    assert_raise_with_message(ArgumentError, /required keywords: x, y\)/) do
+      obj.t(42)
+    end
+  end
 end