ruby--ruby/spec/ruby/core/symbol/comparison_spec.rb

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

describe "Symbol#<=> with Symbol" do
  it "compares individual characters based on their ascii value" do
    ascii_order = Array.new(256) { |x| x.chr.to_sym }
    sort_order = ascii_order.sort
    sort_order.should == ascii_order
  end

  it "returns -1 when self is less than other" do
    (:this <=> :those).should == -1
  end

  it "returns 0 when self is equal to other" do
    (:yep <=> :yep).should == 0
  end

  it "returns 1 when self is greater than other" do
    (:yoddle <=> :griddle).should == 1
  end

  it "considers symbol that comes lexicographically first to be less if the symbols have same size" do
    (:aba <=> :abc).should == -1
    (:abc <=> :aba).should == 1
  end

  it "doesn't consider shorter string to be less if longer string starts with shorter one" do
    (:abc <=> :abcd).should == -1
    (:abcd <=> :abc).should == 1
  end

  it "compares shorter string with corresponding number of first chars of longer string" do
    (:abx <=> :abcd).should == 1
    (:abcd <=> :abx).should == -1
  end
end

describe "Symbol#<=>" do
  it "returns nil if other is a String" do
    (:abc <=> "abc").should be_nil
  end

  it "returns nil if other is a Fixnum" do
    (:abc <=> 1).should be_nil
  end

  it "returns nil if other is an object" do
    obj = mock("string <=>")
    (:abc <=> obj).should be_nil
  end
end