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

# -*- encoding: utf-8 -*-
require_relative '../../spec_helper'
require_relative 'fixtures/classes'

describe "String#downcase" do
  it "returns a copy of self with all uppercase letters downcased" do
    "hELLO".downcase.should == "hello"
    "hello".downcase.should == "hello"
  end

  ruby_version_is ''...'2.4' do
    it "is locale insensitive (only replaces A-Z)" do
      "ÄÖÜ".downcase.should == "ÄÖÜ"

      str = Array.new(256) { |c| c.chr }.join
      expected = Array.new(256) do |i|
        c = i.chr
        c.between?("A", "Z") ? c.downcase : c
      end.join

      str.downcase.should == expected
    end
  end

  ruby_version_is '2.4' do
    describe "full Unicode case mapping" do
      it "works for all of Unicode with no option" do
        "ÄÖÜ".downcase.should == "äöü"
      end

      it "updates string metadata" do
        downcased = "\u{212A}ING".downcase

        downcased.should == "king"
        downcased.size.should == 4
        downcased.bytesize.should == 4
        downcased.ascii_only?.should be_true
      end
    end

    describe "ASCII-only case mapping" do
      it "does not downcase non-ASCII characters" do
        "CÅR".downcase(:ascii).should == "cÅr"
      end
    end

    describe "full Unicode case mapping adapted for Turkic languages" do
      it "downcases characters according to Turkic semantics" do
        "İ".downcase(:turkic).should == "i"
      end

      it "allows Lithuanian as an extra option" do
        "İ".downcase(:turkic, :lithuanian).should == "i"
      end

      it "does not allow any other additional option" do
        lambda { "İ".downcase(:turkic, :ascii) }.should raise_error(ArgumentError)
      end
    end

    describe "full Unicode case mapping adapted for Lithuanian" do
      it "currently works the same as full Unicode case mapping" do
        "İS".downcase(:lithuanian).should == "i\u{307}s"
      end

      it "allows Turkic as an extra option (and applies Turkic semantics)" do
        "İS".downcase(:lithuanian, :turkic).should == "is"
      end

      it "does not allow any other additional option" do
        lambda { "İS".downcase(:lithuanian, :ascii) }.should raise_error(ArgumentError)
      end
    end

    describe "case folding" do
      it "case folds special characters" do
        "ß".downcase.should == "ß"
        "ß".downcase(:fold).should == "ss"
      end
    end

    it "does not allow invalid options" do
      lambda { "ABC".downcase(:invalid_option) }.should raise_error(ArgumentError)
    end
  end

  it "taints result when self is tainted" do
    "".taint.downcase.tainted?.should == true
    "x".taint.downcase.tainted?.should == true
    "X".taint.downcase.tainted?.should == true
  end

  it "returns a subclass instance for subclasses" do
    StringSpecs::MyString.new("FOObar").downcase.should be_an_instance_of(StringSpecs::MyString)
  end
end

describe "String#downcase!" do
  it "modifies self in place" do
    a = "HeLlO"
    a.downcase!.should equal(a)
    a.should == "hello"
  end

  ruby_version_is '2.4' do
    describe "full Unicode case mapping" do
      it "modifies self in place for all of Unicode with no option" do
        a = "ÄÖÜ"
        a.downcase!
        a.should == "äöü"
      end

      it "updates string metadata" do
        downcased = "\u{212A}ING"
        downcased.downcase!

        downcased.should == "king"
        downcased.size.should == 4
        downcased.bytesize.should == 4
        downcased.ascii_only?.should be_true
      end
    end

    describe "ASCII-only case mapping" do
      it "does not downcase non-ASCII characters" do
        a = "CÅR"
        a.downcase!(:ascii)
        a.should == "cÅr"
      end
    end

    describe "full Unicode case mapping adapted for Turkic languages" do
      it "downcases characters according to Turkic semantics" do
        a = "İ"
        a.downcase!(:turkic)
        a.should == "i"
      end

      it "allows Lithuanian as an extra option" do
        a = "İ"
        a.downcase!(:turkic, :lithuanian)
        a.should == "i"
      end

      it "does not allow any other additional option" do
        lambda { a = "İ"; a.downcase!(:turkic, :ascii) }.should raise_error(ArgumentError)
      end
    end

    describe "full Unicode case mapping adapted for Lithuanian" do
      it "currently works the same as full Unicode case mapping" do
        a = "İS"
        a.downcase!(:lithuanian)
        a.should == "i\u{307}s"
      end

      it "allows Turkic as an extra option (and applies Turkic semantics)" do
        a = "İS"
        a.downcase!(:lithuanian, :turkic)
        a.should == "is"
      end

      it "does not allow any other additional option" do
        lambda { a = "İS"; a.downcase!(:lithuanian, :ascii) }.should raise_error(ArgumentError)
      end
    end

    describe "case folding" do
      it "case folds special characters" do
        a = "ß"
        a.downcase!
        a.should == "ß"

        a.downcase!(:fold)
        a.should == "ss"
      end
    end

    it "does not allow invalid options" do
      lambda { a = "ABC"; a.downcase!(:invalid_option) }.should raise_error(ArgumentError)
    end
  end

  it "returns nil if no modifications were made" do
    a = "hello"
    a.downcase!.should == nil
    a.should == "hello"
  end

  it "raises a #{frozen_error_class} when self is frozen" do
    lambda { "HeLlo".freeze.downcase! }.should raise_error(frozen_error_class)
    lambda { "hello".freeze.downcase! }.should raise_error(frozen_error_class)
  end

  with_feature :encoding do
    it "sets the result String encoding to the source String encoding" do
      "ABC".downcase.encoding.should equal(Encoding::UTF_8)
    end
  end
end