* string.c (rb_str_init): introduce String.new(capacity: size)

  [Feature #12024]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53850 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 12 insertions, 0 deletions

diff --git a/test/ruby/test_string.rb b/test/ruby/test_string.rb
index f1633e3d7b..339e8728ab 100644
--- a/test/ruby/test_string.rb
+++ b/test/ruby/test_string.rb
@@ -45,6 +45,18 @@ class TestString < Test::Unit::TestCase
     src.force_encoding("euc-jp")
     assert_equal(src, S(src, encoding: "utf-8"))
     assert_equal(Encoding::UTF_8, S(src, encoding: "utf-8").encoding)
+
+    assert_equal("", S(capacity: 1000))
+    assert_equal(Encoding::ASCII_8BIT, S(capacity: 1000).encoding)
+
+    assert_equal("", S(capacity: 1000, encoding: "euc-jp"))
+    assert_equal(Encoding::EUC_JP, S(capacity: 1000, encoding: "euc-jp").encoding)
+
+    assert_equal("", S("", capacity: 1000))
+    assert_equal(__ENCODING__, S("", capacity: 1000).encoding)
+
+    assert_equal("", S("", capacity: 1000, encoding: "euc-jp"))
+    assert_equal(Encoding::EUC_JP, S("", capacity: 1000, encoding: "euc-jp").encoding)
   end
 
   def test_AREF # '[]'