* string.c (rb_str_ellipsize): new function to ellipsize a string.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@30729 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 46 insertions, 0 deletions

diff --git a/test/-ext-/string/test_ellipsize.rb b/test/-ext-/string/test_ellipsize.rb
new file mode 100644
index 0000000000..6ef7d0a1a3
--- /dev/null
+++ b/test/-ext-/string/test_ellipsize.rb
@@ -0,0 +1,46 @@
+require 'test/unit'
+require "-test-/string/string"
+
+class Test_StringEllipsize < Test::Unit::TestCase
+  def setup
+    @foobar = Bug::String.new("foobar")
+  end
+
+  def assert_equal_with_class(expected, result, *rest)
+    assert_equal(expected.encoding, result.encoding, *rest)
+    assert_equal(expected, result, result.encoding.name)
+    assert_instance_of(Bug::String, result, *rest)
+  end
+
+  def test_longer
+    assert_equal_with_class("", @foobar.ellipsize(0))
+    assert_equal_with_class(".", @foobar.ellipsize(1))
+    assert_equal_with_class("..", @foobar.ellipsize(2))
+    assert_equal_with_class("...", @foobar.ellipsize(3))
+    assert_equal_with_class("f...", @foobar.ellipsize(4))
+    assert_equal_with_class("fo...", @foobar.ellipsize(5))
+  end
+
+  def test_shorter
+    assert_same(@foobar, @foobar.ellipsize(6))
+    assert_same(@foobar, @foobar.ellipsize(7))
+  end
+
+  def test_negative_length
+    assert_raise(IndexError) {@foobar.ellipsize(-1)}
+  end
+
+  def test_nonascii
+    a = "\u3042"
+    encs = Encoding.list.each do |enc|
+      next if enc.dummy?
+      begin
+        s = a.encode(enc)
+        e = "...".encode(enc)
+      rescue
+      else
+        assert_equal_with_class(s*12+e, Bug::String.new(s*20).ellipsize(15))
+      end
+    end
+  end
+end