From f7d4df50c004d775a296b8989bb3ac792db6e639 Mon Sep 17 00:00:00 2001
From: mame <mame@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Fri, 24 Oct 2008 14:01:21 +0000
Subject: [PATCH] * test/ruby/test_array.rb (test_sample): add tests for size
 of   returned array and randomness.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@19922 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog               |  5 +++++
 test/ruby/test_array.rb | 17 +++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index b70a774919..139d8b0fe5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Oct 24 22:59:27 2008  Yusuke Endoh  <mame@tsg.ne.jp>
+
+	* test/ruby/test_array.rb (test_sample): add tests for size of
+	  returned array and randomness.
+
 Fri Oct 24 21:50:21 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* id.h, template/id.h.tmpl (enum ruby_method_ids): reordered.
diff --git a/test/ruby/test_array.rb b/test/ruby/test_array.rb
index 1b917ca77a..cfb36045e3 100644
--- a/test/ruby/test_array.rb
+++ b/test/ruby/test_array.rb
@@ -1545,6 +1545,23 @@ class TestArray < Test::Unit::TestCase
         assert([0, 1, 2].include?(sample))
       }
     end
+
+    srand(0)
+    a = (1..18).to_a
+    (0..20).each do |n|
+      10000.times do
+        b = a.sample(n)
+        assert_equal([n, 18].min, b.uniq.size)
+        assert_equal(a, (a | b).sort)
+        assert_equal(b.sort, (a & b).sort)
+      end
+
+      h = Hash.new(0)
+      10000.times do
+        a.sample(n).each {|x| h[x] += 1 }
+      end
+      assert_operator(h.values.min * 2, :>=, h.values.max) if n != 0
+    end
   end
 
   def test_cycle