require_relative '../spec_helper' describe "Safe navigator" do it "requires a method name to be provided" do -> { eval("obj&. {}") }.should raise_error(SyntaxError) end context "when context is nil" do it "always returns nil" do eval("nil&.unknown").should == nil eval("[][10]&.unknown").should == nil end it "can be chained" do eval("nil&.one&.two&.three").should == nil end it "doesn't evaluate arguments" do obj = Object.new obj.should_not_receive(:m) eval("nil&.unknown(obj.m) { obj.m }") end end context "when context is false" do it "calls the method" do eval("false&.to_s").should == "false" -> { eval("false&.unknown") }.should raise_error(NoMethodError) end end context "when context is truthy" do it "calls the method" do eval("1&.to_s").should == "1" -> { eval("1&.unknown") }.should raise_error(NoMethodError) end end it "takes a list of arguments" do eval("[1,2,3]&.first(2)").should == [1,2] end it "takes a block" do eval("[1,2]&.map { |i| i * 2 }").should == [2, 4] end it "allows assignment methods" do klass = Class.new do attr_reader :foo def foo=(val) @foo = val 42 end end obj = klass.new eval("obj&.foo = 3").should == 3 obj.foo.should == 3 obj = nil eval("obj&.foo = 3").should == nil end it "allows assignment operators" do klass = Class.new do attr_accessor :m def initialize @m = 0 end end obj = klass.new eval("obj&.m += 3") obj.m.should == 3 obj = nil eval("obj&.m += 3").should == nil end it "does not call the operator method lazily with an assignment operator" do klass = Class.new do attr_writer :foo def foo nil end end obj = klass.new -> { eval("obj&.foo += 3") }.should raise_error(NoMethodError) { |e| e.name.should == :+ } end end