You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: test_gem_source.rb
    path of file: ./repos/artichoke/artichoke-backend/vendor/ruby/test/rubygems
    
    the code of the file until where you have to start completion: # frozen_string_literal: true
require_relative 'helper'
require 'rubygems/source'
require 'rubygems/indexer'

class TestGemSource < Gem::TestCase
  def tuple(*args)
    Gem::NameTuple.new(*args)
  end

  def setup
    super

    @specs = spec_fetcher do |fetcher|
      fetcher.spec 'a', '1.a'
      fetcher.gem  'a', 1
      fetcher.spec 'a', 2
      fetcher.spec 'b', 2
    end

    @source = Gem::Source.new(@gem_repo)
  end

  def test_initialize_invalid_uri
    assert_raise URI::InvalidURIError do
      Gem::Source.new 'git@example:a.git'
    end
  end

  def test_initialize_git
    repository = 'git@example:a.git'

    source = Gem::Source::Git.new 'a', repository, 'master', false

    assert_equal repository, source.uri
  end

  def test_ca
    
  def test_load_specs
    released = @source.load_specs(:released).map {|spec| spec.full_name }
    assert_equal %W[a-2 a-1 b-2], released

    cache_dir = File.join Gem.spec_cache_dir, 'gems.example.com%80'
    assert File.exist?(cache_dir), "#{cache_dir} does not exist"

    cache_file = File.join cache_dir, "specs.#{Gem.marshal_version}"
    assert File.exist?(cache_file)
  end

  def test_load_specs_cached
    latest_specs = @source.load_specs :latest

    # Make sure the cached version is actually different:
    latest_specs << Gem::NameTuple.new('cached', Gem::Version.new('1.0.0'), 'ruby')

    @fetcher.data["#{@gem_repo}latest_specs.#{Gem.marshal_version}.gz"] = nil
    @fetcher.data["#{@gem_repo}latest_specs.#{Gem.marshal_version}"] =
      ' ' * Marshal.dump(latest_specs).length

    cache_dir = File.join Gem.spec_cache_dir, 'gems.example.com%80'

    FileUtils.mkdir_p cache_dir

    cache_file = File.join cache_dir, "latest_specs.#{Gem.marshal_version}"

    File.open cache_file, 'wb' do |io|
      Marshal.dump latest_specs, io
    end

    cached_specs = @source.load_specs :latest

    assert_equal latest_specs, cached_specs
  end

  def test_load_specs_cached_empty
    latest_specs = @source.load_specs :latest

    # Make sure the cached version is actually different:
    latest_specs << Gem::NameTuple.new('fixed', Gem::Version.new('1.0.0'), 'ruby')
    # Setup valid data on the 'remote'
    @fetcher.data["#{@gem_repo}latest_specs.#{Gem.marshal_version}.gz"] =
          util_gzip(Marshal.dump(latest_specs))

    cache_dir = File.join Gem.spec_cache_dir, 'gems.example.com%80'

    FileUtils.mkdir_p cache_dir

    cache_file = File.join cache_dir, "latest_specs.#{Gem.marshal_version}"

    File.open cache_file, 'wb' do |io|
      # Setup invalid data in the cache:
      io.write Marshal.dump(latest_specs)[0, 10]
    end

    fixed_specs = @source.load_specs :latest

    assert_equal latest_specs, fixed_specs
  end

  def test_load_specs_from_unavailable_uri
    src = Gem::Source.new("http://not-there.nothing")

    assert_raise Gem::RemoteFetcher::FetchError do
      src.load_specs :latest
    end
  end

  def test_spaceship
    remote    = @source
    specific  = Gem::Source::SpecificFile.new @specs['a-1'].cache_file
    installed = Gem::Source::Installed.new
    local     = Gem::Source::Local.new

    assert_equal(0, remote.<=>(remote), 'remote <=> remote')

    assert_equal(-1, remote.<=>(specific), 'remote <=> specific')
    assert_equal(1, specific.<=>(remote), 'specific <=> remote')

    assert_equal(-1, remote.<=>(local), 'remote <=> local')
    assert_equal(1, local.<=>(remote), 'local <=> remote')

    assert_equal(-1, remote.<=>(installed), 'remote <=> installed')
    assert_equal(1, installed.<=>(remote), 'installed <=> remote')

    no_uri = @source.dup
    no_uri.instance_variable_set :@uri, nil

    assert_equal(-1, remote.<=>(no_uri), 'remote <=> no_uri')
  end

  def test_spaceship_order_is_preserved_when_uri_differs
    sourceA = Gem::Source.new "http://example.com/a"
    sourceB = Gem::Source.new "http://example.com/b"

    assert_equal(0, sourceA.<=>(sourceA), 'sourceA <=> sourceA')
    assert_equal(1, sourceA.<=>(sourceB), 'sourceA <=> sourceB')
    assert_equal(1, sourceB.<=>(sourceA), 'sourceB <=> sourceA')
  end

  def test_update_cache_eh
    assert @source.update_cache?
  end

  def test_update_cache_eh_home_nonexistent
    FileUtils.rmdir Gem.user_home

    refute @source.update_cache?
  end

  def test_typo_squatting
    rubygems_source = Gem::Source.new("https://rubgems.org")
    assert rubygems_source.typo_squatting?("rubygems.org")
    assert rubygems_source.typo_squatting?("rubyagems.org")
    assert rubygems_source.typo_squatting?("rubyasgems.org")
    refute rubygems_source.typo_squatting?("rubysertgems.org")
  end

  def test_typo_squatting_false_positive
    rubygems_source = Gem::Source.new("https://rubygems.org")
    refute rubygems_source.typo_squatting?("rubygems.org")
  end

  def test_typo_squatting_custom_distance_threshold
    rubygems_source = Gem::Source.new("https://rubgems.org")
    distance_threshold = 5
    assert rubygems_source.typo_squatting?("rubysertgems.org", distance_threshold)
  end
end