require_relative '../../spec_helper' ruby_version_is "2.5" do 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 be_an_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 end end