class Gem::Dependency



Valid dependency types.



Dependency name or regular expression.


Allows you to force this dependency to be a prerelease.

Public Class Methods

new(name, *requirements) click to toggle source

Constructs a dependency with name and requirements. The last argument can optionally be the dependency type, which defaults to :runtime.

# File lib/rubygems/dependency.rb, line 37
def initialize name, *requirements
  case name
  when String then # ok
  when Regexp then
    msg = ["NOTE: w/ a regexp is deprecated.",
           " called from #{Gem.location_of_caller.join(":")}"]
    warn msg.join("\n") unless Gem::Deprecate.skip
    raise ArgumentError,
          "dependency name must be a String, was #{name.inspect}"

  type         = Symbol === requirements.last ? requirements.pop : :runtime
  requirements = requirements.first if 1 == requirements.length # unpack

  unless TYPES.include? type
    raise ArgumentError, "Valid types are #{TYPES.inspect}, " +
                         "not #{type.inspect}"

  @name        = name
  @requirement = Gem::Requirement.create requirements
  @type        = type
  @prerelease  = false

  # This is for Marshal backwards compatibility. See the comments in
  # +requirement+ for the dirty details.

  @version_requirements = @requirement

Public Instance Methods

<=>(other) click to toggle source

Dependencies are ordered by name.

# File lib/rubygems/dependency.rb, line 181
def <=> other <=>
Alias for: =~
=~(other) click to toggle source

Uses this dependency as a pattern to compare to other. This dependency will match if the name matches the other's name, and other has only an equal version requirement that satisfies this dependency.

# File lib/rubygems/dependency.rb, line 191
def =~ other
  unless Gem::Dependency === other
    return unless other.respond_to?(:name) && other.respond_to?(:version)
    other =, other.version

  return false unless name ===

  reqs = other.requirement.requirements

  return false unless reqs.length == 1
  return false unless reqs.first.first == '='

  version = reqs.first.last

  requirement.satisfied_by? version
Also aliased as: ===
latest_version?() click to toggle source

Is this dependency simply asking for the latest version of a gem?

# File lib/rubygems/dependency.rb, line 97
def latest_version?
match? name → true or false click to toggle source
match? name, version → true or false
match? spec → true or false

Does this dependency match the specification described by name and version or match spec?

NOTE: Unlike matches_spec? this method does not return true when the version is a prerelease version unless this is a prerelease dependency.

# File lib/rubygems/dependency.rb, line 223
def match? obj, version=nil, allow_prerelease=false
  if !version
    name =
    version = obj.version
    name = obj

  return false unless === name

  version = version

  return true if requirement.none? and not version.prerelease?
  return false if version.prerelease? and
                  not allow_prerelease and
                  not prerelease?

  requirement.satisfied_by? version
matches_spec?(spec) click to toggle source

Does this dependency match spec?

NOTE: This is not a convenience method. Unlike match? this method returns true when spec is a prerelease version even if this dependency is not a prerelease dependency.

# File lib/rubygems/dependency.rb, line 250
def matches_spec? spec
  return false unless name ===
  return true  if requirement.none?

matching_specs(platform_only = false) click to toggle source
# File lib/rubygems/dependency.rb, line 276
def matching_specs platform_only = false
  matches = Gem::Specification.stubs_for(name).find_all { |spec|
    requirement.satisfied_by? spec.version

  if platform_only
    matches.reject! { |spec|
      spec.nil? || !Gem::Platform.match(spec.platform)

  matches.sort_by { |s| s.sort_obj } # HACK: shouldn't be needed
merge(other) click to toggle source

Merges the requirements of other into this dependency

# File lib/rubygems/dependency.rb, line 260
def merge other
  unless name == then
    raise ArgumentError,
          "#{self} and #{other} have different names"

  default = Gem::Requirement.default
  self_req  = self.requirement
  other_req = other.requirement

  return name, self_req  if other_req == default
  return name, other_req if self_req  == default name, self_req.as_list.concat(other_req.as_list)
prerelease?() click to toggle source

Does this dependency require a prerelease?

# File lib/rubygems/dependency.rb, line 89
def prerelease?
  @prerelease || requirement.prerelease?
requirement() click to toggle source

What does this dependency require?

# File lib/rubygems/dependency.rb, line 119
def requirement
  return @requirement if defined?(@requirement) and @requirement

  # @version_requirements and @version_requirement are legacy ivar
  # names, and supported here because older gems need to keep
  # working and Dependency doesn't implement marshal_dump and
  # marshal_load. In a happier world, this would be an
  # attr_accessor. The horrifying instance_variable_get you see
  # below is also the legacy of some old restructurings.
  # Note also that because of backwards compatibility (loading new
  # gems in an old RubyGems installation), we can't add explicit
  # marshaling to this class until we want to make a big
  # break. Maybe 2.0.
  # Children, define explicit marshal and unmarshal behavior for
  # public classes. Marshal formats are part of your public API.

  # REFACTOR: See above

  if defined?(@version_requirement) && @version_requirement
    version = @version_requirement.instance_variable_get :@version
    @version_requirement  = nil
    @version_requirements = version

  @requirement = @version_requirements if defined?(@version_requirements)
requirements_list() click to toggle source
# File lib/rubygems/dependency.rb, line 148
def requirements_list
runtime?() click to toggle source
# File lib/rubygems/dependency.rb, line 167
def runtime?
  @type == :runtime || !@type
specific?() click to toggle source

True if the dependency will not always match the latest version.

# File lib/rubygems/dependency.rb, line 293
def specific?
to_spec() click to toggle source
# File lib/rubygems/dependency.rb, line 326
def to_spec
  matches = self.to_specs

  active = matches.find { |spec| spec && spec.activated? }

  return active if active

  matches.delete_if { |spec| spec.nil? || spec.version.prerelease? } unless prerelease?

to_specs() click to toggle source
# File lib/rubygems/dependency.rb, line 297
def to_specs
  matches = matching_specs true

  # TODO: check Gem.activated_spec[] in case matches falls outside

  if matches.empty? then
    specs = Gem::Specification.find_all { |s|
     == name
            }.map { |x| x.full_name }

    if specs.empty?
      total = Gem::Specification.to_a.size
      msg   = "Could not find '#{name}' (#{requirement}) among #{total} total gem(s)\n"
      msg   = "Could not find '#{name}' (#{requirement}) - did find: [#{specs.join ','}]\n"
    msg << "Checked in 'GEM_PATH=#{Gem.path.join(File::PATH_SEPARATOR)}', execute `gem env` for more information"

    error =        =
    error.requirement = self.requirement
    raise error

  # TODO: any other resolver validations should go here

type() click to toggle source

Dependency type.

# File lib/rubygems/dependency.rb, line 163
def type
  @type ||= :runtime