1 files changed, 233 insertions, 0 deletions
diff --git a/lib/rubygems/request_set/lockfile.rb b/lib/rubygems/request_set/lockfile.rb
new file mode 100644
index 0000000000..8b9c9690d6
--- /dev/null
+++ b/lib/rubygems/request_set/lockfile.rb
@@ -0,0 +1,233 @@
+# frozen_string_literal: true
+
+##
+# Parses a gem.deps.rb.lock file and constructs a LockSet containing the
+# dependencies found inside.  If the lock file is missing no LockSet is
+# constructed.
+
+class Gem::RequestSet::Lockfile
+  ##
+  # Raised when a lockfile cannot be parsed
+
+  class ParseError < Gem::Exception
+    ##
+    # The column where the error was encountered
+
+    attr_reader :column
+
+    ##
+    # The line where the error was encountered
+
+    attr_reader :line
+
+    ##
+    # The location of the lock file
+
+    attr_reader :path
+
+    ##
+    # Raises a ParseError with the given +message+ which was encountered at a
+    # +line+ and +column+ while parsing.
+
+    def initialize(message, column, line, path)
+      @line   = line
+      @column = column
+      @path   = path
+      super "#{message} (at line #{line} column #{column})"
+    end
+  end
+
+  ##
+  # Creates a new Lockfile for the given Gem::RequestSet and +gem_deps_file+
+  # location.
+
+  def self.build(request_set, gem_deps_file, dependencies = nil)
+    request_set.resolve
+    dependencies ||= requests_to_deps request_set.sorted_requests
+    new request_set, gem_deps_file, dependencies
+  end
+
+  def self.requests_to_deps(requests) # :nodoc:
+    deps = {}
+
+    requests.each do |request|
+      spec        = request.spec
+      name        = request.name
+      requirement = request.request.dependency.requirement
+
+      deps[name] = if [Gem::Resolver::VendorSpecification,
+                       Gem::Resolver::GitSpecification].include? spec.class
+        Gem::Requirement.source_set
+      else
+        requirement
+      end
+    end
+
+    deps
+  end
+
+  ##
+  # The platforms for this Lockfile
+
+  attr_reader :platforms
+
+  def initialize(request_set, gem_deps_file, dependencies)
+    @set           = request_set
+    @dependencies  = dependencies
+    @gem_deps_file = File.expand_path(gem_deps_file)
+    @gem_deps_dir  = File.dirname(@gem_deps_file)
+    @platforms = []
+  end
+
+  def add_DEPENDENCIES(out) # :nodoc:
+    out << "DEPENDENCIES"
+
+    out.concat @dependencies.sort.map {|name, requirement|
+      "  #{name}#{requirement.for_lockfile}"
+    }
+
+    out << nil
+  end
+
+  def add_GEM(out, spec_groups) # :nodoc:
+    return if spec_groups.empty?
+
+    source_groups = spec_groups.values.flatten.group_by do |request|
+      request.spec.source.uri
+    end
+
+    source_groups.sort_by {|group,| group.to_s }.map do |group, requests|
+      out << "GEM"
+      out << "  remote: #{group}"
+      out << "  specs:"
+
+      requests.sort_by(&:name).each do |request|
+        next if request.spec.name == "bundler"
+        platform = "-#{request.spec.platform}" unless
+          request.spec.platform == Gem::Platform::RUBY
+
+        out << "    #{request.name} (#{request.version}#{platform})"
+
+        request.full_spec.dependencies.sort.each do |dependency|
+          next if dependency.type == :development
+
+          requirement = dependency.requirement
+          out << "      #{dependency.name}#{requirement.for_lockfile}"
+        end
+      end
+      out << nil
+    end
+  end
+
+  def add_GIT(out, git_requests)
+    return if git_requests.empty?
+
+    by_repository_revision = git_requests.group_by do |request|
+      source = request.spec.source
+      [source.repository, source.rev_parse]
+    end
+
+    by_repository_revision.each do |(repository, revision), requests|
+      out << "GIT"
+      out << "  remote: #{repository}"
+      out << "  revision: #{revision}"
+      out << "  specs:"
+
+      requests.sort_by(&:name).each do |request|
+        out << "    #{request.name} (#{request.version})"
+
+        dependencies = request.spec.dependencies.sort_by(&:name)
+        dependencies.each do |dep|
+          out << "      #{dep.name}#{dep.requirement.for_lockfile}"
+        end
+      end
+      out << nil
+    end
+  end
+
+  def relative_path_from(dest, base) # :nodoc:
+    dest = File.expand_path(dest)
+    base = File.expand_path(base)
+
+    if dest.index(base) == 0
+      offset = dest[base.size + 1..-1]
+
+      return "." unless offset
+
+      offset
+    else
+      dest
+    end
+  end
+
+  def add_PATH(out, path_requests) # :nodoc:
+    return if path_requests.empty?
+
+    out << "PATH"
+    path_requests.each do |request|
+      directory = File.expand_path(request.spec.source.uri)
+
+      out << "  remote: #{relative_path_from directory, @gem_deps_dir}"
+      out << "  specs:"
+      out << "    #{request.name} (#{request.version})"
+    end
+
+    out << nil
+  end
+
+  def add_PLATFORMS(out) # :nodoc:
+    out << "PLATFORMS"
+
+    platforms = requests.map {|request| request.spec.platform }.uniq
+
+    platforms = platforms.sort_by(&:to_s)
+
+    platforms.each do |platform|
+      out << "  #{platform}"
+    end
+
+    out << nil
+  end
+
+  def spec_groups
+    requests.group_by {|request| request.spec.class }
+  end
+
+  ##
+  # The contents of the lock file.
+
+  def to_s
+    out = []
+
+    groups = spec_groups
+
+    add_PATH out, groups.delete(Gem::Resolver::VendorSpecification) { [] }
+
+    add_GIT out, groups.delete(Gem::Resolver::GitSpecification) { [] }
+
+    add_GEM out, groups
+
+    add_PLATFORMS out
+
+    add_DEPENDENCIES out
+
+    out.join "\n"
+  end
+
+  ##
+  # Writes the lock file alongside the gem dependencies file
+
+  def write
+    content = to_s
+
+    File.open "#{@gem_deps_file}.lock", "w" do |io|
+      io.write content
+    end
+  end
+
+  private
+
+  def requests
+    @set.sorted_requests
+  end
+end