Move spec/rubyspec to spec/ruby for consistency

* Other ruby implementations use the spec/ruby directory.
  [Misc #13792] [ruby-core:82287]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59979 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

spec/ruby/core/struct/dig_spec.rb

@@ -0,0 +1,44 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+
+ruby_version_is "2.3" do
+  describe "Struct#dig" do
+    before(:each) do
+      @klass = Struct.new(:a)
+      @instance = @klass.new(@klass.new({ b: [1, 2, 3] }))
+    end
+
+    it "returns the nested value specified by the sequence of keys" do
+      @instance.dig(:a, :a).should == { b: [1, 2, 3] }
+    end
+
+    it "returns the nested value specified if the sequence includes an index" do
+      @instance.dig(:a, :a, :b, 0).should == 1
+    end
+
+    it "returns nil if any intermediate step is nil" do
+      @instance.dig(:b, 0).should == nil
+    end
+
+    it "raises a TypeError if any intermediate step does not respond to #dig" do
+      instance = @klass.new(1)
+      lambda {
+        instance.dig(:a, 3)
+      }.should raise_error(TypeError)
+    end
+
+    it "raises an ArgumentError if no arguments provided" do
+      lambda { @instance.dig }.should raise_error(ArgumentError)
+    end
+
+    it "calls #dig on any intermediate step with the rest of the sequence as arguments" do
+      obj = Object.new
+      instance = @klass.new(obj)
+
+      def obj.dig(*args)
+        {dug: args}
+      end
+
+      instance.dig(:a, :bar, :baz).should == { dug: [:bar, :baz] }
+    end
+  end
+end