Ruby sort - why rspec error when "expected: [7, 6, 5, 5, 4, 3, 3]" seems the same as "got: [7, 6, 5, 5, 4, 3, 3]"?

Question

Result:

Failures:

  1) An usual sorter sorts downwards by default
     Failure/Error: [a,b,c,d,e,f,g].sort.should == [7,6,5,5,4,3,3]
       expected: [7, 6, 5, 5, 4, 3, 3]
            got: [7, 6, 5, 5, 4, 3, 3] (using ==)
     # ./downsort_spec.rb:13:in `block (2 levels) in <top (required)>'

Finished in 0.00077 seconds

Test:

require_relative 'my_sorter.rb'

describe "A usual sorter" do
  it "sorts downwards by default" do
    my_array= [3,5,7,5,3,6,4,2,5,6]
    a=MySorter.new(3)
    b=MySorter.new(5)
    c=MySorter.new(7)
    d=MySorter.new(5)
    e=MySorter.new(3)
    f=MySorter.new(6)
    g=MySorter.new(4)
    [a,b,c,d,e,f,g].sort.should == [7,6,5,5,4,3,3]
  end 
end

Code:

class MySorter
  include Comparable
  attr_reader :value

  def initialize(value)
    @value = value
  end

  def <=> (other)
    if value > other.value then
      -1
    elsif value < other.value then
      1
    else
       0
    end
  end

  def inspect
    @value
  end

end

I have a very simple sort for now, the intent will be a more complex one once I have this working (hence the detail in the comparison method).

Answer 1

You are comparing an array of MySorter objects to an array of Fixnums. You need to change this:

[a,b,c,d,e,f,g].sort.should == [7,6,5,5,4,3,3]

to

[a,b,c,d,e,f,g].sort.map(&:value).should == [7,6,5,5,4,3,3]