Rubygems gemspec template

template.gemspec

#!/usr/bin/env gem build
# -*- coding: utf-8 -*-

module Gem::Specification::SpecificationHelpers
  def self.find_executables(executable_dir = 'bin', options = {})
    raise ArgumentError, "options must be a Hash" unless options.kind_of?(Hash)

    exclude_executables = options['exclude_executables'] || []
    executable_files    = []

    if File.directory?(executable_dir)
      Dir.new(executable_dir).each do |file_name|
        full_file_name = File.join(executable_dir, file_name)

        next if [ '.', '..' ].include?(file_name) || ! File.file?(full_file_name) || exclude_executables.include?(file_name)

        executable_files.push(file_name)
      end if File.readable?(executable_dir)
    end

    return executable_files
  end

  # All extensions are expected to follow the standard structure of <ext_dir>/<extension_name>/extconf.rb
  def self.find_extensions(extension_dirs = [ 'ext' ], options = {})
    raise ArgumentError, "extension_dirs must be an Array" unless extension_dirs.kind_of?(Array)
    raise ArgumentError, "options must be a Hash" unless options.kind_of?(Hash)

    exclude_extensions = options['exclude_extensions'] || []
    extension_files    = []

    extension_dirs.each do |extension_dir|
      next unless File.directory?(extension_dir)

      Dir.new(extension_dir).each do |file_name|
        full_file_name = File.join(extension_dir, file_name)

        next if [ '.', '..' ].include?(file_name) || ! File.directory?(full_file_name) || exclude_extensions.include?(file_name)

        if File.readable?(full_file_name) && Dir.entries(full_file_name).include?("extconf.rb")
          extension_files.push(File.join(full_file_name, "extconf.rb"))
        end
      end if File.readable?(extension_dir)
    end

    return extension_files  
  end

  def self.find_files(search_dirs = [ 'bin', 'doc', 'ext', 'lib' ], options = {})
    raise ArgumentError, "search_dirs must be an Array" unless search_dirs.kind_of?(Array)
    raise ArgumentError, "options must be a Hash" unless options.kind_of?(Hash)

    exclude_dirs   = options['exclude_dirs']  || []
    exclude_files  = options['exclude_files'] || []
    file_listing   = []
    search_subdirs = []

    search_dirs.each do |search_dir|
      next unless File.directory?(search_dir)

      Dir.new(search_dir).each do |file_name|
        next if [ '.', '..' ].include?(file_name)

        full_file_name  = File.join(search_dir, file_name)
        
        if ! File.directory?(full_file_name) && exclude_files.select{ |exclude_file| full_file_name.match(exclude_file) }.empty?
          file_listing.push(full_file_name)
        end

        if File.directory?(full_file_name) && exclude_dirs.select{ |exclude_dir| full_file_name.match(exclude_dir) }.empty?
          search_subdirs.push(full_file_name)
        end
      end if File.readable?(search_dir)
    end

    unless search_subdirs.empty?
      file_listing.concat(find_files(search_subdirs, 'exclude_dirs' => exclude_dirs, 'exclude_files' => exclude_files))
    end

    return file_listing
  end
end

# http://guides.rubygems.org/
Gem::Specification.new do |spec|

  # REQUIRED ATTRIBUTES
  #======================

  # Singular writer for authors
  spec.author = 'John Doe'

  # Sets the list of authors, ensuring it is an array.
  spec.authors = [ 'John Doe', 'Jane Doe' ]

  # Files included in this gem. You cannot append to this accessor, you must assign to it.
  # Only add files you can require to this list, not directories, etc.
  # Directories are automatically stripped from this list when building a gem,
  # other non-files cause an error.
  spec.files = SpecificationHelpers::find_files(search_dirs = [ 'bin', 'doc', 'ext', 'lib' ], 'exclude_dir' => [], 'exclude_files' => [])

  # This gem's name.
  spec.name = 'mygem'

  # The platform this gem runs on.
  #
  # This is usually Gem::Platform::RUBY or Gem::Platform::CURRENT.
  #
  # Most gems contain pure Ruby code; they should simply leave the default value in place.
  # Some gems contain C (or other) code to be compiled into a Ruby “extension”. The gem
  # should leave the default value in place unless the code will only compile on a certain
  # type of system. Some gems consist of pre-compiled code (“binary gems”). It's especially
  # important that they set the platform attribute appropriately. A shortcut is to set the
  # platform to Gem::Platform::CURRENT, which will cause the gem builder to set the platform
  # to the appropriate value for the system on which the build is being performed.
  #
  # If this attribute is set to a non-default value, it will be included in the filename of the
  # gem when it is built
  spec.platform = Gem::Platform::RUBY # || RUBY_PLATFORM

  # Paths in the gem to add to $LOAD_PATH when this gem is activated.
  #
  # See also require_paths
  #
  # If you have an extension you do not need to add "ext" to the require path, the extension
  # build process will copy the extension files into “lib” for you.
  #
  # The default value is "lib"
  spec.require_paths = [ 'lib' ]

  # The version of RubyGems used to create this gem.
  #
  # Do not set this, it is set automatically when the gem is packaged.
  spec.rubygems_version = '0.0.0'

  # A short summary of this gem's description. Displayed in `gem list -d`.
  #
  # The description should be more detailed than the summary.
  spec.summary = 'Summary'

  # This gem's version.
  #
  # The version string can contain numbers and periods, such as 1.0.0. A gem is a 'prerelease'
  # gem if the version has a letter in it, such as 1.0.0.pre.
  spec.version = '0.0.0'

  # RECOMMENDED ATTRIBUTES
  #=======================

  # The license for this gem.
  #
  # The license must be no more than 64 characters.
  #
  # This should just be the name of your license. The full text of the license should be inside
  # of the gem (at the top level) when you build it.
  #
  # The simplest way, is to specify the standard SPDX ID spdx.org/licenses/ for the license.
  # Ideally you should pick one that is OSI (Open Source Initiative)
  # opensource.org/licenses/alphabetical approved.
  #
  # The most commonly used OSI approved licenses are BSD-3-Clause and MIT. GitHub also provides
  # a license picker at choosealicense.com/.
  #
  # You should specify a license for your gem so that people know how they are permitted to use it,
  # and any restrictions you're placing on it. Not specifying a license means all rights are
  # reserved; others have no rights to use the code for any purpose.
  #
  # You can set multiple licenses with licenses=
  spec.license = 'GPL-2'

  # The license(s) for the library.
  #
  # Each license must be a short name, no more than 64 characters.
  #
  # This should just be the name of your license. The full text of the license should be inside
  # of the gem when you build it.
  #
  # See license= for more discussion
  spec.licenses = [  'Apache', 'GPL-2', 'MIT' ]

  # OPTIONAL ATTRIBUTES
  #=======================

  # Adds a development dependency named gem with requirements to this gem.
  #
  # Development dependencies aren't installed by default and aren't activated when a gem
  # is required.
  spec.add_development_dependency('dependent_gem', '~> 1.1', '>= 1.1.4')

  # Adds a runtime dependency named gem with requirements to this gem.
  spec.add_runtime_dependency('runtime_gem', '~> 1.1', '>= 1.1.4')

  # The path in the gem for executable scripts. Usually 'bin'
  spec.bindir = 'bin'

  # The certificate chain used to sign this gem. See Gem::Security for details.
  spec.cert_chain = [ 'gem-public_cert.pem' ]

  # A long description of this gem
  #
  # The description should be more detailed than the summary but not excessively long. A
  # few paragraphs is a recommended length with no examples or formatting.
  spec.description = <<-EOF
    Long
    Description
    Yo
  EOF

  # A contact email address (or addresses) for this gem
  spec.email = [ '[email protected]', '[email protected]' ]

  # Executables included in the gem.
  #
  # For example, the rake gem has rake as an executable. You don’t specify the full path
  # (as in bin/rake); all application-style files are expected to be found in bindir. These
  # files must be executable Ruby files. Files that use bash or other interpreters will not work.
  #
  # Executables included may only be ruby scripts, not scripts for other languages or compiled
  # binaries.
  spec.executables = SpecificationHelpers::find_executables(executable_dir = spec.bindir, 'exclude_executables' => [ 'executable_name'])

  # Extensions to build when installing the gem, specifically the paths to extconf.rb-style files
  # used to compile extensions.
  #
  # These files will be run when the gem is installed, causing the C (or whatever) code to be
  # compiled on the user’s machine.
  spec.extensions = SpecificationHelpers::find_extensions(extension_dirs = [ 'ext' ], 'exclude_extensions' => [ 'extension_name' ])

  # Extra files to add to RDoc such as README or doc/examples.txt
  #
  # When the user elects to generate the RDoc documentation for a gem (typically at install time),
  # all the library files are sent to RDoc for processing. This option allows you to have some
  # non-code files included for a more complete set of documentation.
  spec.extra_rdoc_files = [ 'README', 'doc/guide.txt' ]

  # The URL of this gem's home page
  spec.homepage = 'http://johndoe.com'

  # The metadata holds extra data for this gem that may be useful to other consumers and is settable
  # by gem authors without requiring an update to the rubygems software.
  #
  # Metadata items have the following restrictions:
  #
  # - The metadata must be a Hash object
  # - All keys and values must be Strings
  # - Keys can be a maximum of 128 bytes and values can be a maximum of 1024 bytes
  # - All strings must be UTF-8, no binary data is allowed
  spec.metadata = { 'issue_tracker' => 'https://www.github.com/johndoe/missing/issues' }

  # A message that gets displayed after the gem is installed.
  spec.post_install_message = "Gem is now installed"

  # Specifies the rdoc options to be used when generating API documentation.
  spec.rdoc_options = [ '--opt' , 'opt' ]

  # The version of Ruby required by this gem
  spec.required_ruby_version = '>= 1.8.7'

  # The RubyGems version required by this gem
  spec.required_rubygems_version = '>= 0'

  # Lists the external (to RubyGems) requirements that must be met for this gem to work. It's simply
  # information for the user.
  spec.requirements = [ 'cygwin: package_name', 'multicore cpu' ]

  # The key used to sign this gem. See Gem::Security for details.
  spec.signing_key = File.expand_path('~/.ssh/gem-private_key.pem')
end