Testing Mmo#styles_fit

mmo_test.rb

require 'test_helper'
require 'mocha'

class MmoTest < ActiveSupport::TestCase

  # Set up equivalence classes for the tests
  def setup
    # Equivalence classes
    @styles = {
      "video" => {
        :low => { :w => 1, :h => 1},
        :medium => {:w => 384 + 1, :h => 288 + 1},
        :high => {:w => 768 + 1,:h => 576 + 1},
        :hd => {:w => 1152 + 1,:h => 864 + 1},
      },
      
      "image" => {
        :low => {:w =>  1,:h => 1},
        :medium => {:w => 384 + 1, :h => 288 + 1},
        :high => {:w => 960 + 1, :h => 720 + 1}
      }
    }
    
    # Data table for equivalence classes
    @geometries = {
      "video" => {"w" => [], "h" => []},
      "image" => {"w" => [], "h" => []}
    }
    # Generate test data
    %w{video image}.each{|mtype|
      # Parse all styles for geometry values
      Mmo::STYLES[mtype].select{|k|
        # :thumb and :image "fit" always, so they do not create equivalence class
        ![:thumb, :image].include?(k)
      }.each{|k,v|
        v[:geometry].split(/x/).each_with_index{|n,i|
          # Prepend with 1 smaller value
          @geometries[mtype][i % 2 == 0 ? "w" : "h" ] <<  n.to_i - 1
          
          @geometries[mtype][i % 2 == 0 ? "w" : "h" ] <<  n.to_i
          # Append 120% bigger value too
          @geometries[mtype][i % 2 == 0 ? "w" : "h" ] <<  (n.to_i * 1.2).to_i

          @styles[mtype] ||= {}
          @styles[mtype][k] ||= {}
          @styles[mtype][k][i % 2 == 0 ? "w" : "h" ] = n.to_i
        }
      }
    }
    # Prepend -1 and 0 to each array and append a big int
    @geometries.each{|k,v| v.each{|k1,v1|
        v1.unshift(0)
        v1.unshift(-1)
        v1.push(10000)
      }
    }
  end

  def test_video_styles
    check_styles("video")
  end

  def test_image_styles
    check_styles("image")
  end

  def test_audio_styles
    m = Mmo.new
    m.stubs(:media_type).returns("audio")

    # Fake a selection of supported codecs
    %w{mp3 mp4 wav wmv}.each{|c|
      m.stubs(:info).returns({:codec => c})
      if c == "mp3"
        assert_equal([:mp3, :mp4], m.styles_fit.keys, "MP3 should have both :mp3 and :mp4 style")
      else
        assert_equal([:mp4], m.styles_fit.keys, "Codec #{c} should have only :mp4 style")
      end
    }
  end

  def check_styles(mtype)
    m = Mmo.new
    m.stubs(:media_type).returns(mtype)
    # Traverse all possible combinations
    @geometries[mtype]['w'].each do |w|
      @geometries[mtype]['h'].each do |h|
        # Stub media info
        m.stubs(:info).returns({
            :width => w,
            :height => h,
            :aspect => m.send(:aspect,w,h)
          })
        assert_correct_styles(w,h,m.styles_fit, mtype)
      end
    end
  end

  def assert_correct_styles(w,h,styles, mtype)
    if w < 1 || h < 1
      assert_equal({}, styles, "Zero and Negative size should yield empty result")
      return
    end
    
    assert(styles.keys.include?(:thumb), "Thumbnail should be always generated. styles: w:#{w} h:#{h}, #{styles}")
    assert(styles.keys.include?(:image), "Image should be always generated for videos") if mtype == "video"
    if (styles.has_key?(:image))
      ws,hs = styles[:image][:geometry].split(/x/)

      # Compensate for rounding errors
      assert(w == ws.to_i || h == hs.to_i, "Image should have original size. Styles: #{styles}, w:#{w}, h:#{h}")
    end

    @styles[mtype].each do |k,v|
      if w >= v[:w] || h >= v[:h]
        assert(styles.keys.include?(k), "Style #{k} should be generated. o:#{w}x#{h}, w_min:#{v[:w]}, h_min:#{v[:h]}")
      end
    end
  end
end