require_relative '../../spec_helper' 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