# class Gem::Uninstaller

An `Uninstaller`.

The uninstaller fires pre and post uninstall hooks. Hooks can be added either through a rubygems_plugin.rb file in an installed gem or via a rubygems/defaults/#{RUBY_ENGINE}.rb or rubygems/defaults/operating_system.rb file. See `Gem.pre_uninstall` and `Gem.post_uninstall` for details.

### Attributes

bin_dir[R]

The directory a gem’s executables will be installed into

gem_home[R]

The gem repository the gem will be uninstalled from

spec[R]

The `Gem::Specification` for the gem being uninstalled, only set during `uninstall_gem`

### Public Class Methods

new(gem, options = {}) click to toggle source

Constructs an uninstaller that will uninstall `gem`

    # File lib/rubygems/uninstaller.rb, line 48
    def initialize(gem, options = {})
      # TODO: document the valid options
      @gem                = gem
      @version            = options[:version] || Gem::Requirement.default
      @install_dir        = options[:install_dir]
      @gem_home           = File.realpath(@install_dir || Gem.dir)
      @user_dir           = File.exist?(Gem.user_dir) ? File.realpath(Gem.user_dir) : Gem.user_dir
      @force_executables  = options[:executables]
      @force_all          = options[:all]
      @force_ignore       = options[:ignore]
      @bin_dir            = options[:bin_dir]
      @format_executable  = options[:format_executable]
      @abort_on_dependent = options[:abort_on_dependent]

      # Indicate if development dependencies should be checked when
      # uninstalling. (default: false)
      #
      @check_dev = options[:check_dev]

      if options[:force]
        @force_all = true
        @force_ignore = true
      end

      # only add user directory if install_dir is not set
      @user_install = false
      @user_install = options[:user_install] unless @install_dir

      # Optimization: populated during #uninstall
      @default_specs_matching_uninstall_params = []
    end

### Public Instance Methods

path_ok?(gem_dir, spec) click to toggle source

Is `spec` in `gem_dir`?

    # File lib/rubygems/uninstaller.rb, line 305
    def path_ok?(gem_dir, spec)
      full_path     = File.join gem_dir, "gems", spec.full_name
      original_path = File.join gem_dir, "gems", spec.original_name

      full_path == spec.full_gem_path || original_path == spec.full_gem_path
    end

regenerate_plugins() click to toggle source

Regenerates plugin wrappers after removal.

    # File lib/rubygems/uninstaller.rb, line 294
    def regenerate_plugins
      specification_record = @install_dir ? Gem::SpecificationRecord.from_path(@install_dir) : Gem::Specification.specification_record
      latest = specification_record.latest_spec_for(@spec.name)
      return if latest.nil?

      regenerate_plugins_for(latest, plugin_dir_for(@spec))
    end

remove(spec) click to toggle source

spec

  the spec of the gem to be uninstalled

    # File lib/rubygems/uninstaller.rb, line 241
    def remove(spec)
      unless path_ok?(@gem_home, spec) ||
             (@user_install && path_ok?(@user_dir, spec))
        e = Gem::GemNotInHomeException.new \
          "Gem '#{spec.full_name}' is not installed in directory #{@gem_home}"
        e.spec = spec

        raise e
      end

      raise Gem::FilePermissionError, spec.base_dir unless
        File.writable?(spec.base_dir)

      safe_delete { FileUtils.rm_r spec.full_gem_path }
      safe_delete { FileUtils.rm_r spec.extension_dir }

      old_platform_name = spec.original_name

      gem = spec.cache_file
      gem = File.join(spec.cache_dir, "#{old_platform_name}.gem") unless
        File.exist? gem

      safe_delete { FileUtils.rm_r gem }

      begin
        Gem::RDoc.new(spec).remove
      rescue NameError
      end

      gemspec = spec.spec_file

      unless File.exist? gemspec
        gemspec = File.join(File.dirname(gemspec), "#{old_platform_name}.gemspec")
      end

      safe_delete { FileUtils.rm_r gemspec }
      announce_deletion_of(spec)

      Gem::Specification.reset
    end

remove_all(list) click to toggle source

Removes all gems in `list`.

NOTE: removes uninstalled gems from `list`.

    # File lib/rubygems/uninstaller.rb, line 234
    def remove_all(list)
      list.each {|spec| uninstall_gem spec }
    end

remove_executables(spec) click to toggle source

Removes installed executables and batch files (windows only) for `spec`.

    # File lib/rubygems/uninstaller.rb, line 180
    def remove_executables(spec)
      return if spec.executables.empty?

      executables = spec.executables.clone

      # Leave any executables created by other installed versions
      # of this gem installed.

      list = Gem::Specification.find_all do |s|
        s.name == spec.name && s.version != spec.version
      end

      list.each do |s|
        s.executables.each do |exe_name|
          executables.delete exe_name
        end
      end

      return if executables.empty?

      executables = executables.map {|exec| formatted_program_filename exec }

      remove = if @force_executables.nil?
        ask_yes_no("Remove executables:\n" \
                   "\t#{executables.join ", "}\n\n" \
                   "in addition to the gem?",
                   true)
      else
        @force_executables
      end

      if remove
        bin_dir = @bin_dir || Gem.bindir(spec.base_dir)

        raise Gem::FilePermissionError, bin_dir unless File.writable? bin_dir

        executables.each do |exe_name|
          say "Removing #{exe_name}"

          exe_file = File.join bin_dir, exe_name

          safe_delete { FileUtils.rm exe_file }
          safe_delete { FileUtils.rm "#{exe_file}.bat" }
        end
      else
        say "Executables and scripts will remain installed."
      end
    end

safe_delete(&block) click to toggle source

    # File lib/rubygems/uninstaller.rb, line 371
    def safe_delete(&block)
      block.call
    rescue Errno::ENOENT
      nil
    rescue Errno::EPERM
      e = Gem::UninstallError.new
      e.spec = @spec

      raise e
    end

uninstall() click to toggle source

Performs the uninstall of the gem. This removes the spec, the Gem directory, and the cached .gem file.

    # File lib/rubygems/uninstaller.rb, line 84
    def uninstall
      dependency = Gem::Dependency.new @gem, @version

      list = []

      dirs =
        Gem::Specification.dirs +
        [Gem.default_specifications_dir]

      Gem::Specification.each_spec dirs do |spec|
        next unless dependency.matches_spec? spec

        list << spec
      end

      if list.empty?
        raise Gem::InstallError, "gem #{@gem.inspect} is not installed"
      end

      default_specs, list = list.partition(&:default_gem?)
      warn_cannot_uninstall_default_gems(default_specs - list)
      @default_specs_matching_uninstall_params = default_specs

      list, other_repo_specs = list.partition do |spec|
        @gem_home == spec.base_dir ||
          (@user_install && spec.base_dir == @user_dir)
      end

      list.sort!

      if list.empty?
        return unless other_repo_specs.any?

        other_repos = other_repo_specs.map(&:base_dir).uniq

        message = ["#{@gem} is not installed in GEM_HOME, try:"]
        message.concat other_repos.map {|repo|
          "\tgem uninstall -i #{repo} #{@gem}"
        }

        raise Gem::InstallError, message.join("\n")
      elsif @force_all
        remove_all list

      elsif list.size > 1
        gem_names = list.map(&:full_name)
        gem_names << "All versions"

        say
        _, index = choose_from_list "Select gem to uninstall:", gem_names

        if index == list.size
          remove_all list
        elsif index && index >= 0 && index < list.size
          uninstall_gem list[index]
        else
          say "Error: must enter a number [1-#{list.size + 1}]"
        end
      else
        uninstall_gem list.first
      end
    end

uninstall_gem(spec) click to toggle source

Uninstalls gem `spec`

    # File lib/rubygems/uninstaller.rb, line 150
    def uninstall_gem(spec)
      @spec = spec

      unless dependencies_ok? spec
        if abort_on_dependent? || !ask_if_ok(spec)
          raise Gem::DependencyRemovalException,
            "Uninstallation aborted due to dependent gem(s)"
        end
      end

      Gem.pre_uninstall_hooks.each do |hook|
        hook.call self
      end

      remove_executables @spec
      remove_plugins @spec
      remove @spec

      regenerate_plugins

      Gem.post_uninstall_hooks.each do |hook|
        hook.call self
      end

      @spec = nil
    end

### Private Instance Methods

announce_deletion_of(spec) click to toggle source

    # File lib/rubygems/uninstaller.rb, line 384
    def announce_deletion_of(spec)
      name = spec.full_name
      say "Successfully uninstalled #{name}"
      if default_spec_matches?(spec)
        say(
          "There was both a regular copy and a default copy of #{name}. The " \
            "regular copy was successfully uninstalled, but the default copy " \
            "was left around because default gems can't be removed."
        )
      end
    end

default_spec_matches?(spec) click to toggle source

@return true if the specs of any default gems are ‘==` to the given `spec`.

    # File lib/rubygems/uninstaller.rb, line 397
    def default_spec_matches?(spec)
      !default_specs_that_match(spec).empty?
    end

default_specs_that_match(spec) click to toggle source

@return [Array] specs of default gems that are ‘==` to the given `spec`.

    # File lib/rubygems/uninstaller.rb, line 402
    def default_specs_that_match(spec)
      @default_specs_matching_uninstall_params.select {|default_spec| spec == default_spec }
    end

plugin_dir_for(spec) click to toggle source

    # File lib/rubygems/uninstaller.rb, line 412
    def plugin_dir_for(spec)
      Gem.plugindir(spec.base_dir)
    end

warn_cannot_uninstall_default_gems(specs) click to toggle source

    # File lib/rubygems/uninstaller.rb, line 406
    def warn_cannot_uninstall_default_gems(specs)
      specs.each do |spec|
        say "Gem #{spec.full_name} cannot be uninstalled because it is a default gem"
      end
    end