1 files changed, 25 insertions, 2 deletions
diff --git a/spec/ruby/core/array/shuffle_spec.rb b/spec/ruby/core/array/shuffle_spec.rb
index b255147c75..b84394bcb5 100644
--- a/spec/ruby/core/array/shuffle_spec.rb
+++ b/spec/ruby/core/array/shuffle_spec.rb
@@ -47,6 +47,10 @@ describe "Array#shuffle" do
     [1, 2].shuffle(random: random).should be_an_instance_of(Array)
   end
 
+  it "accepts a Random class for the value for random: argument" do
+    [1, 2].shuffle(random: Random).should be_an_instance_of(Array)
+  end
+
   it "calls #to_int on the Object returned by #rand" do
     value = mock("array_shuffle_random_value")
     value.should_receive(:to_int).at_least(1).times.and_return(0)
@@ -65,9 +69,18 @@ describe "Array#shuffle" do
     -> { [1, 2].shuffle(random: random) }.should raise_error(RangeError)
   end
 
-  it "raises a RangeError if the value is equal to one" do
+  it "raises a RangeError if the value is equal to the Array size" do
     value = mock("array_shuffle_random_value")
-    value.should_receive(:to_int).at_least(1).times.and_return(1)
+    value.should_receive(:to_int).at_least(1).times.and_return(2)
+    random = mock("array_shuffle_random")
+    random.should_receive(:rand).at_least(1).times.and_return(value)
+
+    -> { [1, 2].shuffle(random: random) }.should raise_error(RangeError)
+  end
+
+  it "raises a RangeError if the value is greater than the Array size" do
+    value = mock("array_shuffle_random_value")
+    value.should_receive(:to_int).at_least(1).times.and_return(3)
     random = mock("array_shuffle_random")
     random.should_receive(:rand).at_least(1).times.and_return(value)
 
@@ -93,4 +106,14 @@ describe "Array#shuffle!" do
     -> { ArraySpecs.frozen_array.shuffle! }.should raise_error(FrozenError)
     -> { ArraySpecs.empty_frozen_array.shuffle! }.should raise_error(FrozenError)
   end
+
+  it "matches CRuby with random:" do
+    %w[a b c].shuffle(random: Random.new(1)).should == %w[a c b]
+    (0..10).to_a.shuffle(random: Random.new(10)).should == [2, 6, 8, 5, 7, 10, 3, 1, 0, 4, 9]
+  end
+
+  it "matches CRuby with srand" do
+    srand(123)
+    %w[a b c d e f g h i j k].shuffle.should == %w[a e f h i j d b g k c]
+  end
 end