1 files changed, 74 insertions, 0 deletions
diff --git a/spec/ruby/core/hash/slice_spec.rb b/spec/ruby/core/hash/slice_spec.rb
new file mode 100644
index 0000000000..fd93254517
--- /dev/null
+++ b/spec/ruby/core/hash/slice_spec.rb
@@ -0,0 +1,74 @@
+require_relative '../../spec_helper'
+
+describe "Hash#slice" do
+  before :each do
+    @hash = { a: 1, b: 2, c: 3 }
+  end
+
+  it "returns a new empty hash without arguments" do
+    ret = @hash.slice
+    ret.should_not.equal?(@hash)
+    ret.should.instance_of?(Hash)
+    ret.should == {}
+  end
+
+  it "returns the requested subset" do
+    @hash.slice(:c, :a).should == { c: 3, a: 1 }
+  end
+
+  it "returns a hash ordered in the order of the requested keys" do
+    @hash.slice(:c, :a).keys.should == [:c, :a]
+  end
+
+  it "returns only the keys of the original hash" do
+    @hash.slice(:a, :chunky_bacon).should == { a: 1 }
+  end
+
+  it "returns a Hash instance, even on subclasses" do
+    klass = Class.new(Hash)
+    h = klass.new
+    h[:bar] = 12
+    h[:foo] = 42
+    r = h.slice(:foo)
+    r.should == {foo: 42}
+    r.class.should == Hash
+  end
+
+  it "uses the regular Hash#[] method, even on subclasses that override it" do
+    ScratchPad.record []
+    klass = Class.new(Hash) do
+      def [](value)
+        ScratchPad << :used_subclassed_operator
+        super
+      end
+    end
+
+    h = klass.new
+    h[:bar] = 12
+    h[:foo] = 42
+    h.slice(:foo)
+
+    ScratchPad.recorded.should == []
+  end
+
+  it "does not retain the default value" do
+    h = Hash.new(1)
+    h.slice(:a).default.should == nil
+    h[:a] = 1
+    h.slice(:a).default.should == nil
+  end
+
+  it "does not retain the default_proc" do
+    pr = proc { |h, k| h[k] = [] }
+    h = Hash.new(&pr)
+    h.slice(:a).default_proc.should == nil
+    h[:a] = 1
+    h.slice(:a).default_proc.should == nil
+  end
+
+  it "retains compare_by_identity flag" do
+    h = { a: 9, c: 4 }.compare_by_identity
+    h2 = h.slice(:a)
+    h2.compare_by_identity?.should == true
+  end
+end