round-down

* numeric.c (round_half_down, int_round_half_down): support
  round-down mode.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56897 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 21 insertions, 0 deletions

diff --git a/test/ruby/test_float.rb b/test/ruby/test_float.rb
index 74744bfaa2..aed387029e 100644
--- a/test/ruby/test_float.rb
+++ b/test/ruby/test_float.rb
@@ -701,6 +701,27 @@ class TestFloat < Test::Unit::TestCase
     assert_equal(-7.1364, -7.1364499.round(4, half: :up))
   end
 
+  def test_round_half_down
+    assert_equal(12.0, 12.5.round(half: :down))
+    assert_equal(13.0, 13.5.round(half: :down))
+
+    assert_equal(2.1, 2.15.round(1, half: :down))
+    assert_equal(2.2, 2.25.round(1, half: :down))
+    assert_equal(2.3, 2.35.round(1, half: :down))
+
+    assert_equal(-2.1, -2.15.round(1, half: :down))
+    assert_equal(-2.2, -2.25.round(1, half: :down))
+    assert_equal(-2.3, -2.35.round(1, half: :down))
+
+    assert_equal(7.1364, 7.13645.round(4, half: :down))
+    assert_equal(7.1365, 7.1364501.round(4, half: :down))
+    assert_equal(7.1364, 7.1364499.round(4, half: :down))
+
+    assert_equal(-7.1364, -7.13645.round(4, half: :down))
+    assert_equal(-7.1365, -7.1364501.round(4, half: :down))
+    assert_equal(-7.1364, -7.1364499.round(4, half: :down))
+  end
+
   def test_round_half_invalid
     assert_raise_with_message(ArgumentError, /xxx/) {
       1.0.round(half: "\0xxx")