ruby--ruby/spec/ruby/core/string/uminus_spec.rb

require File.expand_path('../../../spec_helper', __FILE__)

ruby_version_is "2.3" do
  describe 'String#-@' do
    it 'returns self if the String is frozen' do
      input  = 'foo'.freeze
      output = -input

      output.equal?(input).should == true
      output.frozen?.should == true
    end

    it 'returns a frozen copy if the String is not frozen' do
      input  = 'foo'
      output = -input

      output.frozen?.should == true
      output.should == 'foo'
    end

    ruby_version_is "2.5" do
      it "returns the same object for equal unfrozen strings" do
        origin = "this is a string"
        dynamic = %w(this is a string).join(' ')

        origin.should_not equal(dynamic)
        (-origin).should equal(-dynamic)
      end

      it "returns the same object when it's called on the same String literal" do
        (-"unfrozen string").should equal(-"unfrozen string")
        (-"unfrozen string").should_not equal(-"another unfrozen string")
      end

      it "is an identity function if the string is frozen" do
        dynamic = %w(this string is frozen).join(' ').freeze

        (-dynamic).should equal(dynamic)

        dynamic.should_not equal("this string is frozen".freeze)
        (-dynamic).should_not equal("this string is frozen".freeze)
        (-dynamic).should_not equal(-"this string is frozen".freeze)
      end
    end
  end
end