spec/ruby/core/string/chr_spec.rb


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require_relative '../../spec_helper'

describe "String#chr" do
  it "returns a copy of self" do
    s = 'e'
    s.should_not equal s.chr
  end

  it "returns a String" do
    'glark'.chr.should be_an_instance_of(String)
  end

  it "returns an empty String if self is an empty String" do
    "".chr.should == ""
  end

  it "returns a 1-character String" do
    "glark".chr.size.should == 1
  end

  it "returns the character at the start of the String" do
    "Goodbye, world".chr.should == "G"
  end

  it "returns a String in the same encoding as self" do
    "\x24".encode(Encoding::US_ASCII).chr.encoding.should == Encoding::US_ASCII
  end

  it "understands multi-byte characters" do
    s = "\u{9879}"
    s.bytesize.should == 3
    s.chr.should == s
  end

  it "understands Strings that contain a mixture of character widths" do
    three = "\u{8082}"
    three.bytesize.should == 3
    four = "\u{77082}"
    four.bytesize.should == 4
    "#{three}#{four}".chr.should == three
  end
end