1 files changed, 120 insertions, 0 deletions
diff --git a/spec/ruby/core/hash/element_reference_spec.rb b/spec/ruby/core/hash/element_reference_spec.rb
new file mode 100644
index 0000000000..b5ca56e84b
--- /dev/null
+++ b/spec/ruby/core/hash/element_reference_spec.rb
@@ -0,0 +1,120 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/classes', __FILE__)
+
+describe "Hash#[]" do
+  it "returns the value for key" do
+    obj = mock('x')
+    h = { 1 => 2, 3 => 4, "foo" => "bar", obj => obj, [] => "baz" }
+    h[1].should == 2
+    h[3].should == 4
+    h["foo"].should == "bar"
+    h[obj].should == obj
+    h[[]].should == "baz"
+  end
+
+  it "returns nil as default default value" do
+    { 0 => 0 }[5].should == nil
+  end
+
+  it "returns the default (immediate) value for missing keys" do
+    h = Hash.new(5)
+    h[:a].should == 5
+    h[:a] = 0
+    h[:a].should == 0
+    h[:b].should == 5
+  end
+
+  it "calls subclass implementations of default" do
+    h = HashSpecs::DefaultHash.new
+    h[:nothing].should == 100
+  end
+
+  it "does not create copies of the immediate default value" do
+    str = "foo"
+    h = Hash.new(str)
+    a = h[:a]
+    b = h[:b]
+    a << "bar"
+
+    a.should equal(b)
+    a.should == "foobar"
+    b.should == "foobar"
+  end
+
+  it "returns the default (dynamic) value for missing keys" do
+    h = Hash.new { |hsh, k| k.kind_of?(Numeric) ? hsh[k] = k + 2 : hsh[k] = k }
+    h[1].should == 3
+    h['this'].should == 'this'
+    h.should == { 1 => 3, 'this' => 'this' }
+
+    i = 0
+    h = Hash.new { |hsh, key| i += 1 }
+    h[:foo].should == 1
+    h[:foo].should == 2
+    h[:bar].should == 3
+  end
+
+  it "does not return default values for keys with nil values" do
+    h = Hash.new(5)
+    h[:a] = nil
+    h[:a].should == nil
+
+    h = Hash.new { 5 }
+    h[:a] = nil
+    h[:a].should == nil
+  end
+
+  it "compares keys with eql? semantics" do
+    { 1.0 => "x" }[1].should == nil
+    { 1.0 => "x" }[1.0].should == "x"
+    { 1 => "x" }[1.0].should == nil
+    { 1 => "x" }[1].should == "x"
+  end
+
+  it "compares key via hash" do
+    x = mock('0')
+    x.should_receive(:hash).and_return(0)
+
+    h = {}
+    # 1.9 only calls #hash if the hash had at least one entry beforehand.
+    h[:foo] = :bar
+    h[x].should == nil
+  end
+
+  it "does not compare keys with different #hash values via #eql?" do
+    x = mock('x')
+    x.should_not_receive(:eql?)
+    x.stub!(:hash).and_return(0)
+
+    y = mock('y')
+    y.should_not_receive(:eql?)
+    y.stub!(:hash).and_return(1)
+
+    { y => 1 }[x].should == nil
+  end
+
+  it "compares keys with the same #hash value via #eql?" do
+    x = mock('x')
+    x.should_receive(:eql?).and_return(true)
+    x.stub!(:hash).and_return(42)
+
+    y = mock('y')
+    y.should_not_receive(:eql?)
+    y.stub!(:hash).and_return(42)
+
+    { y => 1 }[x].should == 1
+  end
+
+  it "finds a value via an identical key even when its #eql? isn't reflexive" do
+    x = mock('x')
+    x.should_receive(:hash).at_least(1).and_return(42)
+    x.stub!(:eql?).and_return(false) # Stubbed for clarity and latitude in implementation; not actually sent by MRI.
+
+    { x => :x }[x].should == :x
+  end
+
+  it "supports keys with private #hash method" do
+    key = HashSpecs::KeyWithPrivateHash.new
+    { key => 42 }[key].should == 42
+  end
+end