Use capture_output instead of capture_io

test/ruby/test_enumerator.rb

@@ -79,7 +79,7 @@ class TestEnumerator < Test::Unit::TestCase
     assert_raise(NoMethodError) { enum.each {} }
     enum.freeze
     assert_raise(ArgumentError) {
-      capture_io do
+      capture_output do
         # warning: Enumerator.new without a block is deprecated; use Object#to_enum
         enum.__send__(:initialize, @obj, :foo)
       end

test/ruby/test_pack.rb

@@ -764,7 +764,7 @@ EXPECTED
 
     $VERBOSE = true
 
-    _, err = capture_io do
+    _, err = capture_output do
       assert_equal "\000", [0].pack("*U")
     end
 
@@ -783,7 +783,7 @@ EXPECTED
 
     $VERBOSE = true
 
-    _, err = capture_io do
+    _, err = capture_output do
       assert_equal [0], "\000".unpack("*U")
     end
 

tool/lib/test/unit/assertions.rb

@@ -214,7 +214,7 @@ module Test
       # See also: #assert_silent
 
       def assert_output stdout = nil, stderr = nil
-        out, err = capture_io do
+        out, err = capture_output do
           yield
         end
 

tool/test/testunit/test_minitest_unit.rb

@@ -1070,11 +1070,11 @@ class TestMiniTestUnitTestCase < Test::Unit::TestCase
     end
   end
 
-  def test_capture_io
+  def test_capture_output
     @assertion_count = 0
 
     non_verbose do
-      out, err = capture_io do
+      out, err = capture_output do
         puts 'hi'
         $stderr.puts 'bye!'
       end