1 files changed, 42 insertions, 0 deletions
diff --git a/spec/ruby/core/hash/rehash_spec.rb b/spec/ruby/core/hash/rehash_spec.rb
new file mode 100644
index 0000000000..09315737b6
--- /dev/null
+++ b/spec/ruby/core/hash/rehash_spec.rb
@@ -0,0 +1,42 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/classes', __FILE__)
+
+describe "Hash#rehash" do
+  it "reorganizes the hash by recomputing all key hash codes" do
+    k1 = [1]
+    k2 = [2]
+    h = {}
+    h[k1] = 0
+    h[k2] = 1
+
+    k1 << 2
+    h.key?(k1).should == false
+    h.keys.include?(k1).should == true
+
+    h.rehash.should equal(h)
+    h.key?(k1).should == true
+    h[k1].should == 0
+
+    k1 = mock('k1')
+    k2 = mock('k2')
+    v1 = mock('v1')
+    v2 = mock('v2')
+
+    v1.should_not_receive(:hash)
+    v2.should_not_receive(:hash)
+
+    h = { k1 => v1, k2 => v2 }
+
+    k1.should_receive(:hash).twice.and_return(0)
+    k2.should_receive(:hash).twice.and_return(0)
+
+    h.rehash
+    h[k1].should == v1
+    h[k2].should == v2
+  end
+
+  it "raises a RuntimeError if called on a frozen instance" do
+    lambda { HashSpecs.frozen_hash.rehash  }.should raise_error(RuntimeError)
+    lambda { HashSpecs.empty_frozen_hash.rehash }.should raise_error(RuntimeError)
+  end
+end