* 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, 16 insertions, 3 deletions

diff --git a/test/-ext-/string/test_capacity.rb b/test/-ext-/string/test_capacity.rb
index 54f3caf32e..48d2deadee 100644
--- a/test/-ext-/string/test_capacity.rb
+++ b/test/-ext-/string/test_capacity.rb
@@ -4,16 +4,29 @@ require '-test-/string'
 require 'rbconfig/sizeof'
 
 class Test_StringCapacity < Test::Unit::TestCase
+  def capa(str)
+    Bug::String.capacity(str)
+  end
+
   def test_capacity_embeded
     size = RbConfig::SIZEOF['void*'] * 3 - 1
-    assert_equal size, Bug::String.capacity('foo')
+    assert_equal size, capa('foo')
   end
 
   def test_capacity_shared
-    assert_equal 0, Bug::String.capacity(:abcdefghijklmnopqrstuvwxyz.to_s)
+    assert_equal 0, capa(:abcdefghijklmnopqrstuvwxyz.to_s)
   end
 
   def test_capacity_normal
-    assert_equal 128, Bug::String.capacity('1'*128)
+    assert_equal 128, capa('1'*128)
+  end
+
+  def test_s_new_capacity
+    assert_equal("", String.new(capacity: 1000))
+    assert_equal(String, String.new(capacity: 1000).class)
+    assert_equal(10000, capa(String.new(capacity: 10000)))
+
+    assert_equal("", String.new(capacity: -1000))
+    assert_equal(capa(String.new(capacity: -10000)), capa(String.new(capacity: -1000)))
   end
 end