1 files changed, 97 insertions, 0 deletions
diff --git a/test/ruby/test_call.rb b/test/ruby/test_call.rb
index ffbda1fdb9..dd1936c4e2 100644
--- a/test/ruby/test_call.rb
+++ b/test/ruby/test_call.rb
@@ -123,6 +123,25 @@ class TestCall < Test::Unit::TestCase
    assert_equal([1, 2, {kw: 3}], f(*a, kw: 3))
   end
 
+  def test_forward_argument_init
+    o = Object.new
+    def o.simple_forward_argument_init(a=eval('b'), b=1)
+      [a, b]
+    end
+
+    def o.complex_forward_argument_init(a=eval('b'), b=eval('kw'), kw: eval('kw2'), kw2: 3)
+      [a, b, kw, kw2]
+    end
+
+    def o.keyword_forward_argument_init(a: eval('b'), b: eval('kw'), kw: eval('kw2'), kw2: 3)
+      [a, b, kw, kw2]
+    end
+
+    assert_equal [nil, 1], o.simple_forward_argument_init
+    assert_equal [nil, nil, 3, 3], o.complex_forward_argument_init
+    assert_equal [nil, nil, 3, 3], o.keyword_forward_argument_init
+  end
+
   def test_call_bmethod_proc
     pr = proc{|sym| sym}
     define_singleton_method(:a, &pr)
@@ -374,6 +393,84 @@ class TestCall < Test::Unit::TestCase
     assert_equal({splat_modified: false}, b)
   end
 
+  def test_anon_splat
+    r2kh = Hash.ruby2_keywords_hash(kw: 2)
+    r2kea = [r2kh]
+    r2ka = [1, r2kh]
+
+    def self.s(*) ->(*a){a}.call(*) end
+    assert_equal([], s)
+    assert_equal([1], s(1))
+    assert_equal([{kw: 2}], s(kw: 2))
+    assert_equal([{kw: 2}], s(**{kw: 2}))
+    assert_equal([1, {kw: 2}], s(1, kw: 2))
+    assert_equal([1, {kw: 2}], s(1, **{kw: 2}))
+    assert_equal([{kw: 2}], s(*r2kea))
+    assert_equal([1, {kw: 2}], s(*r2ka))
+
+    singleton_class.remove_method(:s)
+    def self.s(*, kw: 0) [*->(*a){a}.call(*), kw] end
+    assert_equal([0], s)
+    assert_equal([1, 0], s(1))
+    assert_equal([2], s(kw: 2))
+    assert_equal([2], s(**{kw: 2}))
+    assert_equal([1, 2], s(1, kw: 2))
+    assert_equal([1, 2], s(1, **{kw: 2}))
+    assert_equal([2], s(*r2kea))
+    assert_equal([1, 2], s(*r2ka))
+
+    singleton_class.remove_method(:s)
+    def self.s(*, **kw) [*->(*a){a}.call(*), kw] end
+    assert_equal([{}], s)
+    assert_equal([1, {}], s(1))
+    assert_equal([{kw: 2}], s(kw: 2))
+    assert_equal([{kw: 2}], s(**{kw: 2}))
+    assert_equal([1, {kw: 2}], s(1, kw: 2))
+    assert_equal([1, {kw: 2}], s(1, **{kw: 2}))
+    assert_equal([{kw: 2}], s(*r2kea))
+    assert_equal([1, {kw: 2}], s(*r2ka))
+
+    singleton_class.remove_method(:s)
+    def self.s(*, kw: 0, **kws) [*->(*a){a}.call(*), kw, kws] end
+    assert_equal([0, {}], s)
+    assert_equal([1, 0, {}], s(1))
+    assert_equal([2, {}], s(kw: 2))
+    assert_equal([2, {}], s(**{kw: 2}))
+    assert_equal([1, 2, {}], s(1, kw: 2))
+    assert_equal([1, 2, {}], s(1, **{kw: 2}))
+    assert_equal([2, {}], s(*r2kea))
+    assert_equal([1, 2, {}], s(*r2ka))
+  end
+
+  def test_anon_splat_mutated_bug_21757
+    args = [1, 2]
+    kw = {bug: true}
+
+    def self.m(*); end
+    m(*args, bug: true)
+    assert_equal(2, args.length)
+
+    proc = ->(*) { }
+    proc.(*args, bug: true)
+    assert_equal(2, args.length)
+
+    def self.m2(*); end
+    m2(*args, **kw)
+    assert_equal(2, args.length)
+
+    proc = ->(*) { }
+    proc.(*args, **kw)
+    assert_equal(2, args.length)
+
+    def self.m3(*, **nil); end
+    assert_raise(ArgumentError) { m3(*args, bug: true) }
+    assert_equal(2, args.length)
+
+    proc = ->(*, **nil) { }
+    assert_raise(ArgumentError) { proc.(*args, bug: true) }
+    assert_equal(2, args.length)
+  end
+
   def test_kwsplat_block_eval_order
     def self.t(**kw, &b) [kw, b] end