Initial commit

LICENSE

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+Copyright (c) Josef Strzibny.
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+'Software'), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

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+# WORK IN PROGRESS
+
+# gem-compare
+
+## Description
+
+## Installation
+
+## Usage
+
+### Supported options
+
+## Requirements
+
+## Copyright
+
+Released under the MIT license. Feel free to contribute!

Rakefile

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+require 'rubygems/package_task'
+require 'rake/testtask'
+require 'rdoc/task'
+
+gemspec = Gem::Specification.new do |s|
+  s.name     = "gem-compare"
+  s.version  = "0.0.1"
+  s.platform = Gem::Platform::RUBY
+  s.summary     = "RubyGems plugin for comparing gem versions."
+  s.description = <<-EOF
+                    `gem-compare` is a RubyGems plugin that helps to compare versions of the given gem.
+		                It searches for differences in metadata as well as in files.
+                  EOF
+  s.homepage = "http://github.com/strzibny/gem-compare"
+  s.licenses = ["MIT"]
+  s.author   = "Josef Stribny"
+  s.email    = "strzibny@strzibny.name"
+  s.required_ruby_version     = ">= 1.9.3"
+  s.required_rubygems_version = ">= 1.8"
+  s.files = FileList["README.md", "LICENSE", "Rakefile",
+                     "lib/**/*.rb", "lib/**/**/*.rb", "test/**/test*.rb"]
+  #TODO: add requires, diffy, rainbow
+end
+
+Gem::PackageTask.new gemspec do |pkg|
+end
+
+Rake::RDocTask.new do |rd|
+  rd.main = "README.md"
+  rd.rdoc_files.include("README.md", "lib/**/*.rb")
+end
+
+Rake::TestTask.new('test') do |t|
+  t.libs << 'test'
+  t.pattern = 'test/**/test*.rb'
+  t.verbose = true
+end
+
+task :default => [:test]

lib/rubygems/commands/compare_command.rb

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+require 'rubygems/command'
+require 'rubygems/comparator'
+
+class Gem::Commands::CompareCommand < Gem::Command
+  def initialize
+    super 'compare', 'Compare gem\'s versions and generate a report of changes.',
+      :output => Dir.pwd
+
+    add_option('-a', '--all', 'Show every comparison.') do
+      options[:log_all] = true
+    end
+
+    add_option('-k', '--keep-all', 'Keep downloaded and extracted gem files.') do
+      options[:keep_all] = true
+    end
+
+    add_option('-n', '--no-color', 'Do not colorize output.') do
+      options[:no_color] = true
+    end
+
+    add_option('-pPARAM', '--param=PARAM', 'Compare only a given paramater.') do |param, options|
+      options[:param] = param
+    end
+
+    add_option('-b', '--brief', 'Include only important changes in the report.') do
+      options[:log_all] = false
+      options[:brief] = true
+    end
+
+  end
+
+  def arguments # :nodoc:
+    args = <<-EOF
+          GEMNAME               gem name
+          VERSION [VERSION ...] list of versions to compare
+    EOF
+    return args.gsub(/^\s+/, '')
+  end
+
+  def description # :nodoc:
+    desc = <<-EOF
+           gem-compare is a RubyGems plugin that compares versions of the given gem.
+           It searches for differences in metadata as well as in files.
+    EOF
+    return desc.gsub(/^\s+/, '')
+  end
+
+  def usage # :nodoc:
+    "#{program_name} GEMNAME VERSION [VERSION ...]"
+  end
+
+  def execute
+    gem_name = options[:args].shift
+    versions = options[:args]
+
+    # No gem specified
+    unless gem_name
+      raise Gem::CommandLineError,
+        "Please specify a gem (e.g. gem compare foo VERSION [VERSION ...])"
+    end
+
+    # No versions specified
+    if versions.empty?
+      raise Gem::CommandLineError,
+        "Please specify versions you want to compare (e.g. gem compare foo 0.1.0 0.2.0)"
+    end
+
+    comparator = Gem::Comparator.new(options)
+    comparator.compare_versions(gem_name, versions)
+    comparator.print_results
+  end
+end

lib/rubygems/comparator.rb

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+#####
+# TODO:
+# - compare Gemfiles in detail
+# - specs from rubygems json api
+#   https://api.rubygems.org/quick/Marshal.4.8/json-1.5.5-java.gemspec.rz
+# - packagers brief mode
+#####
+
+require 'tmpdir'
+require 'rbconfig'
+require 'rainbow'
+require 'rubygems/package'
+require 'rubygems/dependency'
+require 'rubygems/spec_fetcher'
+require 'rubygems/comparator/base'
+require 'rubygems/comparator/report'
+require 'rubygems/comparator/spec_comparator'
+require 'rubygems/comparator/file_list_comparator'
+require 'rubygems/comparator/dependency_comparator'
+
+class Gem::Comparator
+  include Gem::Comparator::Base
+  attr_accessor :options, :report
+
+  ##
+  # Set the working dir and process options
+  #
+  # Creates temporal directory if the gem files shouldn't be kept
+
+  def initialize(options)
+    unless options[:keep_all]
+      options[:output] = Dir.mktmpdir
+    end
+
+    if options[:param]
+      unless ((SPEC_PARAMS.include? options[:param]) ||
+              (SPEC_FILES_PARAMS.include? options[:param]) ||
+              (DEPENDENCY_PARAMS.include? "#{options[:param]}".to_sym))
+        warn('Invalid parameter.')
+        exit 1
+      end
+    end
+
+    if options[:no_color]
+      Rainbow.enabled = false
+    end
+
+    @options = options
+    @output = {}
+
+    # Results from the comparison
+    @report = Gem::Comparator::Report.new
+  end
+
+  ##
+  # Compare versions
+  #
+  # Compares file lists, requirements, other meta data
+
+  def compare_versions(gem_name, versions)
+    packages = []
+
+    # Expand versions (<=, >=, ~>) and sort them
+    versions = expand_versions(gem_name, versions)
+    if versions.size == 1
+      warn 'Only one version specified, no version to compare to. Specify at lease two versions.'
+      exit 1
+    end
+
+    versions.each do |version|
+      pkg = download_gem(gem_name, version)
+      packages << pkg
+    end
+
+    [SpecComparator, FileListComparator, DependencyComparator].each do |c|
+      comparator = c.new
+      @report = comparator.compare(packages, @report, @options)
+    end
+
+    # Clean up
+    FileUtils.rm_rf options[:output] unless options[:keep_all]
+  end
+
+  def print_results
+    info 'Printing results...'
+    @report.print
+  end
+
+  private
+
+    def expand_versions(gem_name, versions)
+      info 'Expanding versions...'
+      expanded = []
+      versions.each do |version|
+        if version =~ VERSION_REGEX
+          expanded << version
+          next
+        end
+        op, v = (version.scan /(>=|<=|~>)(.*)/).flatten
+
+        # Supported operator and version?
+        if OPERATORS.include?(op) && v =~ VERSION_REGEX
+          dep = Gem::Dependency.new gem_name, version
+      	  specs_and_sources, errors = Gem::SpecFetcher.fetcher.spec_for_dependency dep
+      	  specs_and_sources.each do |s|
+      	    expanded << s[0].version
+      	  end
+        else
+          warn "Unsupported version specification: #{version}, skipping."
+        end
+      end
+      expanded.uniq.map{ |v| Gem::Version.new v }.sort.map(&:to_s)
+    end
+
+    def gem_file_name(gem_name, version)
+     "#{gem_name}-#{version}.gem"
+    end
+
+    def download_gem(gem_name, version)
+      gem_file = gem_file_name(gem_name, version)
+
+      # Cache
+      if File.exists? File.join(@options[:output], gem_file)
+        info "#{gem_file} exists, using already downloaded file."
+
+        package = Gem::Package.new File.join(@options[:output], gem_file)
+        return package
+      end
+
+      dep = Gem::Dependency.new gem_name, version
+      specs_and_sources, errors = Gem::SpecFetcher.fetcher.spec_for_dependency dep
+      spec, source = specs_and_sources.max_by { |s,| s.version }
+
+      raise "Gem #{gem_name} in #{version} doesn't exist." if spec.nil?
+
+      Dir.chdir @options[:output] do
+        source.download spec
+      end
+
+      package = Gem::Package.new File.join(@options[:output], gem_file)
+      puts "#{gem_file} downloaded."
+
+      package
+    end
+
+    def download_gems?
+      options[:param] && SPEC_FILES_PARAMS.include?(options[:param])
+    end
+
+end

lib/rubygems/comparator/base.rb

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+require 'rainbow'
+
+class Gem::Comparator
+  module Base
+    include Gem::UserInteraction
+
+    class DiffCommandMissing < StandardError; end
+
+    SPACE = ' '
+    DEFAULT_INDENT = SPACE*7
+    OPERATORS = ['=', '!=', '>', '<', '>=', '<=', '~>']
+    VERSION_REGEX = /\A(\d+\.){0,}\d+(\.[a-zA-Z]+\d{0,1}){0,1}\z/
+    SHEBANG_REGEX = /\A#!.*/
+    FAIL = Rainbow('!!').red.bright
+    SUCCESS = Rainbow('OK').green.bright
+    SPEC_PARAMS = %w[ author authors name platform require_paths rubygems_version summary
+                      license licenses  bindir cert_chain description email executables
+                      extensions homepage metadata post_install_message rdoc_options
+                      required_ruby_version required_rubygems_version requirements
+                      signing_key has_rdoc date version ].sort
+    SPEC_FILES_PARAMS = %w[ files test_files extra_rdoc_files ]
+    DEPENDENCY_PARAMS = [ :runtime, :development ]
+
+    private
+
+      def warn(msg)
+        say Rainbow("WARNING: #{msg}").red
+      end
+
+      def info(msg)
+        say msg if Gem.configuration.really_verbose
+      end
+
+      def check_diff_command_is_installed
+        begin
+          IO.popen('diff --version')
+        rescue Exception
+          raise DiffCommandMissing, 'Calling `diff` command failed. Do you have it installed?'
+        end
+      end
+  end
+end