diff --git a/language/reserved_keywords.rb b/language/reserved_keywords.rb new file mode 100644 index 000000000..6c40e34cc --- /dev/null +++ b/language/reserved_keywords.rb @@ -0,0 +1,149 @@ +require_relative '../spec_helper' + +describe "Ruby's reserved keywords" do + # Copied from https://github.com/ruby/ruby/blob/master/defs/keywords + keywords = %w[ + alias + and + begin + BEGIN + break + case + class + def + defined? + do + else + elsif + end + END + ensure + false + for + if + in + module + next + nil + not + or + redo + rescue + retry + return + self + super + then + true + undef + unless + until + when + while + yield + __ENCODING__ + __FILE__ + __LINE__ + ] + + keywords.each do |name| + describe "keyword '#{name}'" do + it "can't be used as local variable name" do + -> { eval(<<~RUBY) }.should raise_error(SyntaxError) + #{name} = :local_variable + RUBY + end + + if name == "defined?" + it "can't be used as an instance variable name" do + -> { eval(<<~RUBY) }.should raise_error(SyntaxError) + @#{name} = :instance_variable + RUBY + end + + it "can't be used as a class variable name" do + -> { eval(<<~RUBY) }.should raise_error(SyntaxError) + class C + @@#{name} = :class_variable + end + RUBY + end + + it "can't be used as a global variable name" do + -> { eval(<<~RUBY) }.should raise_error(SyntaxError) + $#{name} = :global_variable + RUBY + end + else + it "can be used as an instance variable name" do + result = eval <<~RUBY + @#{name} = :instance_variable + @#{name} + RUBY + + result.should == :instance_variable + end + + it "can be used as a class variable name" do + result = eval <<~RUBY + class C + @@#{name} = :class_variable + @@#{name} + end + RUBY + + result.should == :class_variable + end + + it "can be used as a global variable name" do + result = eval <<~RUBY + $#{name} = :global_variable + $#{name} + RUBY + + result.should == :global_variable + end + end + + it "can't be used as a positional parameter name" do + -> { eval(<<~RUBY) }.should raise_error(SyntaxError) + def x(#{name}); end + RUBY + end + + invalid_kw_param_names = ["BEGIN","END","defined?"] + + if invalid_kw_param_names.include?(name) + it "can't be used a keyword parameter name" do + -> { eval(<<~RUBY) }.should raise_error(SyntaxError) + def m(#{name}:); end + RUBY + end + else + it "can be used a keyword parameter name" do + result = instance_eval <<~RUBY + def m(#{name}:) + binding.local_variable_get(:#{name}) + end + + m(#{name}: :argument) + RUBY + + result.should == :argument + end + end + + it "can be used as a method name" do + result = instance_eval <<~RUBY + def #{name} + :method_return_value + end + + send(:#{name}) + RUBY + + result.should == :method_return_value + end + end + end +end