1 files changed, 67 insertions, 0 deletions
diff --git a/spec/ruby/core/kernel/freeze_spec.rb b/spec/ruby/core/kernel/freeze_spec.rb
new file mode 100644
index 0000000000..961c1bccf0
--- /dev/null
+++ b/spec/ruby/core/kernel/freeze_spec.rb
@@ -0,0 +1,67 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/classes', __FILE__)
+
+describe "Kernel#freeze" do
+  it "prevents self from being further modified" do
+    o = mock('o')
+    o.frozen?.should be_false
+    o.freeze
+    o.frozen?.should be_true
+  end
+
+  it "returns self" do
+    o = Object.new
+    o.freeze.should equal(o)
+  end
+
+  describe "on integers" do
+    it "has no effect since they are already frozen" do
+      1.frozen?.should be_true
+      1.freeze
+
+      bignum = bignum_value
+      bignum.frozen?.should be_true
+      bignum.freeze
+    end
+  end
+
+  describe "on a Float" do
+    it "has no effect since it is already frozen" do
+      1.2.frozen?.should be_true
+      1.2.freeze
+    end
+  end
+
+  describe "on a Symbol" do
+    it "has no effect since it is already frozen" do
+      :sym.frozen?.should be_true
+      :sym.freeze
+    end
+  end
+
+  describe "on true, false and nil" do
+    it "has no effect since they are already frozen" do
+      nil.frozen?.should be_true
+      true.frozen?.should be_true
+      false.frozen?.should be_true
+
+      nil.freeze
+      true.freeze
+      false.freeze
+    end
+  end
+
+  it "causes mutative calls to raise RuntimeError" do
+    o = Class.new do
+      def mutate; @foo = 1; end
+    end.new
+    o.freeze
+    lambda {o.mutate}.should raise_error(RuntimeError)
+  end
+
+  it "causes instance_variable_set to raise RuntimeError" do
+    o = Object.new
+    o.freeze
+    lambda {o.instance_variable_set(:@foo, 1)}.should raise_error(RuntimeError)
+  end
+end