cask: add mirror stanza

Library/Homebrew/cask/cask.rb

@@ -305,11 +305,15 @@ def eql?(other)
 
  def to_h
  url_specs = url&.specs.dup
- case url_specs&.dig(:user_agent)
- when :default
- url_specs.delete(:user_agent)
- when Symbol
- url_specs[:user_agent] = ":#{url_specs[:user_agent]}"
+ mirror_specs = Array(mirror).map { |m| m&.specs.dup }
+
+ [url_specs, *mirror_specs].each do |specs|
+ case specs&.dig(:user_agent)
+ when :default
+ specs.delete(:user_agent)
+ when Symbol
+ specs[:user_agent] = ":#{specs[:user_agent]}"
+ end
  end
 
  {
@@ -322,6 +326,8 @@ def to_h
  "homepage" => homepage,
  "url" => url,
  "url_specs" => url_specs,
+ "mirror" => mirror,
+ "mirror_specs" => mirror_specs,
  "appcast" => appcast,
  "version" => version,
  "installed" => installed_version,

Library/Homebrew/cask/cask.rbi

@@ -54,6 +54,8 @@ module Cask
 
  def url; end
 
+ def mirror; end
+
  def version; end
  end
 end

Library/Homebrew/cask/cask_loader.rb

@@ -320,6 +320,15 @@ def load(config:)
  end
 
  url json_cask[:url], **json_cask.fetch(:url_specs, {}) if json_cask[:url].present?
+ json_cask[:mirror]&.each_with_index do |cask_mirror, cask_mirror_index|
+ cask_mirror_specs = json_cask[:mirror_specs]&.fetch(cask_mirror_index, nil).to_h
+ user_agent = cask_mirror_specs[:user_agent]
+ cask_mirror_specs[:user_agent] = user_agent[1..].to_sym if user_agent && user_agent[0] == ":"
+ if (using = cask_mirror_specs[:using])
+ cask_mirror_specs[:using] = using.to_sym
+ end
+ mirror cask_mirror, **cask_mirror_specs
+ end
  appcast json_cask[:appcast] if json_cask[:appcast].present?
  json_cask[:name]&.each do |cask_name|
  name cask_name

Library/Homebrew/cask/download.rb

@@ -19,14 +19,16 @@ def initialize(cask, quarantine: nil)
  super()
 
  @cask = cask
+ @urls = [cask.url, *cask.mirror].compact
+ @urls_index = 0
  @quarantine = quarantine
  end
 
  sig { override.returns(T.nilable(::URL)) }
  def url
- return if cask.url.nil?
+ return if @urls.blank?
 
- @url ||= ::URL.new(cask.url.to_s, cask.url.specs)
+ @url = ::URL.new(@urls[@urls_index].to_s, @urls[@urls_index].specs)
  end
 
  sig { override.returns(T.nilable(::Checksum)) }
@@ -51,9 +53,17 @@ def version
  def fetch(quiet: nil, verify_download_integrity: true, timeout: nil)
  downloader.quiet! if quiet
 
+ @urls_index = 0
  begin
  super(verify_download_integrity: false, timeout: timeout)
  rescue DownloadError => e
+ @urls_index += 1
+ if @urls_index < @urls.length
+ @downloader = nil
+ puts "Trying a mirror..."
+ retry
+ end
+ @urls_index = 0
  error = CaskError.new("Download failed on Cask '#{cask}' with message: #{e.cause}")
  error.set_backtrace e.backtrace
  raise error
@@ -97,7 +107,7 @@ def quarantine(path)
  return unless Quarantine.available?
 
  if @quarantine
- Quarantine.cask!(cask: @cask, download_path: path)
+ Quarantine.cask!(cask: @cask, download_path: path, download_url: @url.to_s)
  else
  Quarantine.release!(download_path: path)
  end

Library/Homebrew/cask/dsl.rb

@@ -83,6 +83,7 @@ class DSL
  :sha256,
  :staged_path,
  :url,
+ :mirror,
  :version,
  :appdir,
  :deprecate!,
@@ -216,6 +217,19 @@ def url(*args, **options, &block)
  end
  end
 
+ # @api public
+ def mirror(*args, **options, &block)
+ @mirror ||= []
+ return @mirror if args.empty? && options.empty? && !block
+
+ caller_location = T.must(caller_locations).fetch(0)
+ @mirror << if block
+ URL.new(*args, **options, caller_location: caller_location, dsl: self, &block)
+ else
+ URL.new(*args, **options, caller_location: caller_location)
+ end
+ end
+
  # @api public
  def appcast(*args, **kwargs)
  set_unique_stanza(:appcast, args.empty? && kwargs.empty?) do

Library/Homebrew/cask/quarantine.rb

@@ -122,7 +122,7 @@ def self.release!(download_path: nil)
  raise CaskQuarantineReleaseError.new(download_path, quarantiner.stderr)
  end
 
- def self.cask!(cask: nil, download_path: nil, action: true)
+ def self.cask!(cask: nil, download_path: nil, action: true, download_url: nil)
  return if cask.nil? || download_path.nil?
 
  return if detect(download_path)
@@ -134,7 +134,7 @@ def self.cask!(cask: nil, download_path: nil, action: true)
  *swift_target_args,
  QUARANTINE_SCRIPT,
  download_path,
- cask.url.to_s,
+ download_url || cask.url.to_s,
  cask.homepage.to_s,
  ],
  print_stderr: false)