* test/ruby/test_array.rb (test_sample): add tests for size of

  returned array and randomness.


git-svn-id: http://svn.ruby-lang.org/repos/ruby/trunk@19922 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 17 insertions, 0 deletions

diff --git a/test/ruby/test_array.rb b/test/ruby/test_array.rb
index 1b917ca77..cfb36045e 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