Make sure codebase conforms to standard.rb style guide

.standard.yml

@@ -0,0 +1,14 @@
+# ChunkyPNG uses and enforces standard.rb as code style (see https://github.com/testdouble/standard).
+# For backwards compatilibity and idiosyncratic preferences of the main author,
+# there are some minor differences listed in here.
+
+ignore:
+- lib/chunky_png/**/*.rb:
+  # We allow `for` loops in the codebase, especially in hot paths,
+  # because they perform better than `each` blocks.
+  - "Style/For"
+
+- spec/chunky_png/**/*.rb:
+  # In RSpec, having to follow this rule will cause expectations to
+  # be less readable, specifically blocks for the `change` matcher.
+  - "Lint/AmbiguousBlockAssociation"

Gemfile

@@ -1,10 +1,10 @@
-source 'https://rubygems.org'
+source "https://rubygems.org"
 gemspec
 
 platforms :jruby do
-  gem 'jruby-openssl'
+  gem "jruby-openssl"
 end
 
 platform :rbx do
-  gem 'rubysl'
+  gem "rubysl"
 end

Rakefile

@@ -1,11 +1,11 @@
 require "bundler/gem_tasks"
 require "rspec/core/rake_task"
 
-Dir['tasks/*.rake'].each { |file| load(file) }
+Dir["tasks/*.rake"].each { |file| load(file) }
 
 RSpec::Core::RakeTask.new(:spec) do |task|
   task.pattern = "./spec/**/*_spec.rb"
-  task.rspec_opts = ['--color']
+  task.rspec_opts = ["--color"]
 end
 
 task default: [:spec]

benchmarks/decoding_benchmark.rb

@@ -1,36 +1,36 @@
-require 'rubygems'
-require 'bundler/setup'
+require "rubygems"
+require "bundler/setup"
 
-require 'benchmark'
-require 'chunky_png'
+require "benchmark"
+require "chunky_png"
 
 def image_file(name)
-  File.join(File.dirname(__FILE__), '..', 'spec', 'resources', name)
+  File.join(File.dirname(__FILE__), "..", "spec", "resources", name)
 end
 
 def image_data(name)
   data = nil
-  File.open(image_file(name), 'rb') { |f| data = f.read }
+  File.open(image_file(name), "rb") { |f| data = f.read }
   data
 end
 
-no_filtering_stream    = image_data('pixelstream_fast_rgba.png')
-up_filtering_stream    = image_data('pixelstream_reference.png')
-paeth_filtering_stream = image_data('pixelstream_best_compression.png')
-rgba_pixelstream       = image_data('pixelstream.rgba')
-rgb_pixelstream        = image_data('pixelstream.rgb')
+no_filtering_stream    = image_data("pixelstream_fast_rgba.png")
+up_filtering_stream    = image_data("pixelstream_reference.png")
+paeth_filtering_stream = image_data("pixelstream_best_compression.png")
+rgba_pixelstream       = image_data("pixelstream.rgba")
+rgb_pixelstream        = image_data("pixelstream.rgb")
 
-n = (ENV['N'] || '5').to_i
+n = (ENV["N"] || "5").to_i
 
 puts "---------------------------------------------"
 puts "ChunkyPNG (#{ChunkyPNG::VERSION}) decoding benchmark (n=#{n})"
 puts "---------------------------------------------"
 puts
 
 Benchmark.bmbm do |x|
-  x.report('PNG - no filtering')    { n.times { ChunkyPNG::Image.from_blob(no_filtering_stream) } }
-  x.report('PNG - UP filtering')    { n.times { ChunkyPNG::Image.from_blob(up_filtering_stream) } }
-  x.report('PNG - PAETH filtering') { n.times { ChunkyPNG::Image.from_blob(paeth_filtering_stream) } }
-  x.report('From RGBA pixelstream') { n.times { ChunkyPNG::Image.from_rgba_stream(240, 180, rgba_pixelstream) } }
-  x.report('From RGB pixelstream')  { n.times { ChunkyPNG::Image.from_rgb_stream(240, 180, rgb_pixelstream) } }
+  x.report("PNG - no filtering")    { n.times { ChunkyPNG::Image.from_blob(no_filtering_stream) } }
+  x.report("PNG - UP filtering")    { n.times { ChunkyPNG::Image.from_blob(up_filtering_stream) } }
+  x.report("PNG - PAETH filtering") { n.times { ChunkyPNG::Image.from_blob(paeth_filtering_stream) } }
+  x.report("From RGBA pixelstream") { n.times { ChunkyPNG::Image.from_rgba_stream(240, 180, rgba_pixelstream) } }
+  x.report("From RGB pixelstream")  { n.times { ChunkyPNG::Image.from_rgb_stream(240, 180, rgb_pixelstream) } }
 end

benchmarks/encoding_benchmark.rb

@@ -1,40 +1,43 @@
-require 'rubygems'
-require 'bundler/setup'
+require "rubygems"
+require "bundler/setup"
 
-require 'benchmark'
-require 'chunky_png'
+require "benchmark"
+require "chunky_png"
 
 image = ChunkyPNG::Image.new(240, 180, ChunkyPNG::Color::TRANSPARENT)
 
 # set some random pixels
+
+# rubocop:disable Layout/ExtraSpacing, Layout/SpaceInsideParens
 image[10, 20] = ChunkyPNG::Color.rgba(255,   0,   0, 255)
 image[50, 87] = ChunkyPNG::Color.rgba(  0, 255,   0, 255)
 image[33, 99] = ChunkyPNG::Color.rgba(  0,   0, 255, 255)
+# rubocop:enable Layout/ExtraSpacing, Layout/SpaceInsideParens
 
-n = (ENV['N'] || '5').to_i
+n = (ENV["N"] || "5").to_i
 
 puts "---------------------------------------------"
 puts "ChunkyPNG (#{ChunkyPNG::VERSION}) encoding benchmark (n=#{n})"
 puts "---------------------------------------------"
 puts
 
 Benchmark.bmbm do |x|
-  x.report('Autodetect (indexed)')  { n.times { image.to_blob } }
+  x.report("Autodetect (indexed)") { n.times { image.to_blob } }
 
   # Presets
-  x.report(':no_compression')    { n.times { image.to_blob(:no_compression) } }
-  x.report(':fast_rgba')         { n.times { image.to_blob(:fast_rgba) } }
-  x.report(':fast_rgb')          { n.times { image.to_blob(:fast_rgb) } }
-  x.report(':good_compression')  { n.times { image.to_blob(:good_compression) } }
-  x.report(':best_compression')  { n.times { image.to_blob(:best_compression) } }
+  x.report(":no_compression")    { n.times { image.to_blob(:no_compression) } }
+  x.report(":fast_rgba")         { n.times { image.to_blob(:fast_rgba) } }
+  x.report(":fast_rgb")          { n.times { image.to_blob(:fast_rgb) } }
+  x.report(":good_compression")  { n.times { image.to_blob(:good_compression) } }
+  x.report(":best_compression")  { n.times { image.to_blob(:best_compression) } }
 
   # Some options
-  x.report(':rgb')        { n.times { image.to_blob(color_mode: ChunkyPNG::COLOR_TRUECOLOR) } }
-  x.report(':rgba')       { n.times { image.to_blob(color_mode: ChunkyPNG::COLOR_TRUECOLOR_ALPHA) } }
-  x.report(':indexed')    { n.times { image.to_blob(color_mode: ChunkyPNG::COLOR_INDEXED) } }
-  x.report(':interlaced') { n.times { image.to_blob(interlaced: true) } }
+  x.report(":rgb")        { n.times { image.to_blob(color_mode: ChunkyPNG::COLOR_TRUECOLOR) } }
+  x.report(":rgba")       { n.times { image.to_blob(color_mode: ChunkyPNG::COLOR_TRUECOLOR_ALPHA) } }
+  x.report(":indexed")    { n.times { image.to_blob(color_mode: ChunkyPNG::COLOR_INDEXED) } }
+  x.report(":interlaced") { n.times { image.to_blob(interlaced: true) } }
 
   # Exports
-  x.report('to RGBA pixelstream') { n.times { image.to_rgba_stream } }
-  x.report('to RGB pixelstream')  { n.times { image.to_rgb_stream } }
+  x.report("to RGBA pixelstream") { n.times { image.to_rgba_stream } }
+  x.report("to RGB pixelstream")  { n.times { image.to_rgb_stream } }
 end

benchmarks/filesize_benchmark.rb

@@ -1,10 +1,10 @@
-require 'rubygems'
-require 'bundler/setup'
+require "rubygems"
+require "bundler/setup"
 
-require 'benchmark'
-require 'chunky_png'
+require "benchmark"
+require "chunky_png"
 
-files = ['pixelstream_reference.png', 'operations.png', 'clock.png']
+files = ["pixelstream_reference.png", "operations.png", "clock.png"]
 
 def encode_png(image, constraints = {})
   filesize = nil
@@ -13,7 +13,7 @@ def encode_png(image, constraints = {})
 end
 
 files.each do |file|
-  filename = File.join(File.dirname(__FILE__), '..', 'spec', 'resources', file)
+  filename = File.join(File.dirname(__FILE__), "..", "spec", "resources", file)
   image = ChunkyPNG::Canvas.from_file(filename)
 
   puts "#{file}: #{image.width}x#{image.height} - #{image.palette.size} colors"

chunky_png.gemspec

@@ -1,11 +1,9 @@
-# -*- encoding: utf-8 -*-
-
-lib = File.expand_path('../lib', __FILE__)
+lib = File.expand_path("../lib", __FILE__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
-require 'chunky_png/version'
+require "chunky_png/version"
 
 Gem::Specification.new do |s|
-  s.name    = 'chunky_png'
+  s.name    = "chunky_png"
 
   # Do not change the version and date fields by hand. This will be done
   # automatically by the gem release script.
@@ -31,22 +29,22 @@ Gem::Specification.new do |s|
     provides a massive speed boost to encoding and decoding.
   EOT
 
-  s.authors  = ['Willem van Bergen']
-  s.email    = ['willem@railsdoctors.com']
-  s.homepage = 'https://github.com/wvanbergen/chunky_png/wiki'
-  s.license  = 'MIT'
+  s.authors  = ["Willem van Bergen"]
+  s.email    = ["willem@railsdoctors.com"]
+  s.homepage = "https://github.com/wvanbergen/chunky_png/wiki"
+  s.license  = "MIT"
   s.metadata = {
-    "source_code_uri"   => "https://github.com/wvanbergen/chunky_png",
-    "wiki_uri"          => "https://github.com/wvanbergen/chunky_png/wiki",
+    "source_code_uri" => "https://github.com/wvanbergen/chunky_png",
+    "wiki_uri" => "https://github.com/wvanbergen/chunky_png/wiki",
   }
 
-  s.add_development_dependency('rake')
-  s.add_development_dependency('standard')
-  s.add_development_dependency('yard', '~> 0.9')
-  s.add_development_dependency('rspec', '~> 3')
+  s.add_development_dependency("rake")
+  s.add_development_dependency("standard")
+  s.add_development_dependency("yard", "~> 0.9")
+  s.add_development_dependency("rspec", "~> 3")
 
-  s.rdoc_options << '--title' << s.name << '--main' << 'README.rdoc' << '--line-numbers' << '--inline-source'
-  s.extra_rdoc_files = ['README.md', 'BENCHMARKING.rdoc', 'CONTRIBUTING.rdoc', 'CHANGELOG.rdoc']
+  s.rdoc_options << "--title" << s.name << "--main" << "README.rdoc" << "--line-numbers" << "--inline-source"
+  s.extra_rdoc_files = ["README.md", "BENCHMARKING.rdoc", "CONTRIBUTING.rdoc", "CHANGELOG.rdoc"]
 
   s.files = `git ls-files`.split($/)
   s.test_files = s.files.grep(%r{^(test|spec|features)/})

lib/chunky_png.rb

@@ -1,8 +1,7 @@
 # Basic requirements from standard library
-require 'set'
-require 'zlib'
-require 'stringio'
-require 'enumerator'
+require "set"
+require "zlib"
+require "stringio"
 
 # ChunkyPNG - the pure ruby library to access PNG files.
 #
@@ -22,7 +21,6 @@
 #
 # @author Willem van Bergen
 module ChunkyPNG
-
   ###################################################
   # PNG international standard defined constants
   ###################################################
@@ -131,7 +129,7 @@ class InvalidUTF8 < ChunkyPNG::Exception
   class ExpectationFailed < ChunkyPNG::Exception
   end
 
-  # Exception that is raised if an expectation fails.
+  # Exception that when provided coordinates are out of bounds for the canvas
   class OutOfBounds < ChunkyPNG::ExpectationFailed
   end
 
@@ -152,21 +150,21 @@ class UnitsUnknown < ChunkyPNG::Exception
   EXTRA_BYTE = "\0".force_encoding(Encoding::BINARY).freeze
 end
 
-require 'chunky_png/version'
+require "chunky_png/version"
 
 # PNG file structure
-require 'chunky_png/datastream'
-require 'chunky_png/chunk'
+require "chunky_png/datastream"
+require "chunky_png/chunk"
 
 # Colors
-require 'chunky_png/palette'
-require 'chunky_png/color'
+require "chunky_png/palette"
+require "chunky_png/color"
 
 # Geometry
-require 'chunky_png/point'
-require 'chunky_png/vector'
-require 'chunky_png/dimension'
+require "chunky_png/point"
+require "chunky_png/vector"
+require "chunky_png/dimension"
 
 # Canvas / Image classes
-require 'chunky_png/canvas'
-require 'chunky_png/image'
+require "chunky_png/canvas"
+require "chunky_png/image"

lib/chunky_png/canvas.rb

@@ -1,14 +1,14 @@
-require 'chunky_png/canvas/png_encoding'
-require 'chunky_png/canvas/png_decoding'
-require 'chunky_png/canvas/adam7_interlacing'
-require 'chunky_png/canvas/stream_exporting'
-require 'chunky_png/canvas/stream_importing'
-require 'chunky_png/canvas/data_url_exporting'
-require 'chunky_png/canvas/data_url_importing'
-require 'chunky_png/canvas/operations'
-require 'chunky_png/canvas/drawing'
-require 'chunky_png/canvas/resampling'
-require 'chunky_png/canvas/masking'
+require "chunky_png/canvas/png_encoding"
+require "chunky_png/canvas/png_decoding"
+require "chunky_png/canvas/adam7_interlacing"
+require "chunky_png/canvas/stream_exporting"
+require "chunky_png/canvas/stream_importing"
+require "chunky_png/canvas/data_url_exporting"
+require "chunky_png/canvas/data_url_importing"
+require "chunky_png/canvas/operations"
+require "chunky_png/canvas/drawing"
+require "chunky_png/canvas/resampling"
+require "chunky_png/canvas/masking"
 
 module ChunkyPNG
   # The ChunkyPNG::Canvas class represents a raster image as a matrix of
@@ -56,7 +56,6 @@ class Canvas
     #   This array always should have +width * height+ elements.
     attr_reader :pixels
 
-
     #################################################################
     # CONSTRUCTORS
     #################################################################
@@ -78,9 +77,10 @@ class Canvas
     def initialize(width, height, initial = ChunkyPNG::Color::TRANSPARENT)
       @width, @height = width, height
 
-      if initial.kind_of?(Array)
-        unless initial.length == width * height
-          raise ArgumentError, "The initial array should have #{width}x#{height} = #{width*height} elements!"
+      if initial.is_a?(Array)
+        pixel_count = width * height
+        unless initial.length == pixel_count
+          raise ArgumentError, "The initial array should have #{width}x#{height} = #{pixel_count} elements!"
         end
         @pixels = initial
       else
@@ -104,7 +104,6 @@ def self.from_canvas(canvas)
       new(canvas.width, canvas.height, canvas.pixels.dup)
     end
 
-
     #################################################################
     # PROPERTIES
     #################################################################
@@ -274,7 +273,7 @@ def palette
     # @return [true, false] True if the size and pixel values of the other
     #   canvas are exactly the same as this canvas's size and pixel values.
     def eql?(other)
-      other.kind_of?(self.class) &&
+      other.is_a?(self.class) &&
         other.pixels == pixels &&
         other.width == width &&
         other.height == height
@@ -298,7 +297,7 @@ def to_image
     def inspect
       inspected = "<#{self.class.name} #{width}x#{height} ["
       for y in 0...height
-        inspected << "\n\t[" << row(y).map { |p| ChunkyPNG::Color.to_hex(p) }.join(' ') << ']'
+        inspected << "\n\t[" << row(y).map { |p| ChunkyPNG::Color.to_hex(p) }.join(" ") << "]"
       end
       inspected << "\n]>"
     end
@@ -360,13 +359,13 @@ def assert_width!(vector_length)
 
     # Throws an exception if the matrix width and height does not match this canvas' dimensions.
     def assert_size!(matrix_width, matrix_height)
-      if width  != matrix_width
+      if width != matrix_width
         raise ChunkyPNG::ExpectationFailed,
-          'The width of the matrix does not match the canvas width!'
+          "The width of the matrix does not match the canvas width!"
       end
       if height != matrix_height
         raise ChunkyPNG::ExpectationFailed,
-          'The height of the matrix does not match the canvas height!'
+          "The height of the matrix does not match the canvas height!"
       end
       true
     end