Add DownloadStrategy and Cask::Headers for custom :headers support

accepts a :user_agent argument and/or multiple :cookies
  headers :user_agent => 'Netscape/1.0', :cookies => { :cookey => "r00t" }

Also adds a standalone :fake_user_agent for a default UserAgent (Chrome)
  fake_user_agent
References #1175, #958

lib/cask.rb

@@ -11,9 +11,11 @@ class Cask; end
 require 'cask/cli'
 require 'cask/container'
 require 'cask/download'
+require 'cask/download_strategy'
 require 'cask/dsl'
 require 'cask/exceptions'
 require 'cask/fetcher'
+require 'cask/headers'
 require 'cask/installer'
 require 'cask/link_checker'
 require 'cask/locations'

lib/cask/download.rb

@@ -11,8 +11,8 @@ def perform
     resource = Resource.new(cask.title) do |r|
       r.url     cask.url.to_s
       r.version cask.version
-    end
-    downloader = CurlDownloadStrategy.new(cask.title, resource)
+    end    
+    downloader = Cask::DownloadStrategy.new(cask, resource)
     downloaded_path = downloader.fetch
 
     _check_sums(downloaded_path, cask.sums) unless cask.sums === 0

lib/cask/download_strategy.rb

@@ -0,0 +1,25 @@
+require 'cgi'
+
+class Cask::DownloadStrategy < CurlDownloadStrategy
+  attr_reader :headers, :url
+
+  def initialize(cask, resource)
+    @cask    = cask
+    @headers = cask.headers
+    @url     = resource.url
+    super(cask.title, resource)
+  end
+
+  def _fetch
+    curl(*curl_options)
+  end
+
+  private
+  def default_options
+    [url, '-C', downloaded_size, '-o', temporary_path]
+  end
+
+  def curl_options
+    default_options.concat(headers.curl_options)
+  end
+end

lib/cask/dsl.rb

@@ -18,6 +18,10 @@ def artifacts; self.class.artifacts; end
 
   def caveats; ''; end
 
+  def headers; self.class.headers; end
+
+  def fake_user_agent; self.class.fake_user_agent; end
+
   module ClassMethods
     def homepage(homepage=nil)
       @homepage ||= homepage
@@ -27,6 +31,14 @@ def url(url=nil)
       @url ||= Cask::UnderscoreSupportingURI.parse(url)
     end
 
+    def headers(headers={})
+      @headers ||= Cask::Headers.new(headers)
+    end
+
+    def fake_user_agent
+      headers({:user_agent => 'Chrome/32.0.1000.00'})
+    end
+
     def version(version=nil)
       @version ||= version
     end

lib/cask/headers.rb

@@ -0,0 +1,37 @@
+require 'cgi'
+
+class Cask::Headers
+  attr_reader :headers
+
+  def initialize(args)
+    @headers = args
+    create_methods_from_headers
+  end
+
+  def curl_options(options=[])
+    headers.map do |option, _|
+      options.concat(send("#{option}_args")) if (!!send(option))
+    end
+    options.flatten
+  end
+
+  private
+  def create_methods_from_headers
+    headers.map do |header, option|
+      (class << self; self; end).class_eval do
+        define_method(header.to_sym) { option }
+      end
+    end
+  end
+
+  def user_agent_args
+    ['-A', user_agent]
+  end
+
+  def cookies_args
+    all_cookies = cookies.map do |name, value|
+      "#{CGI.escape(name.to_s)}=#{CGI.escape(value.to_s)}"
+    end
+    ['-b', all_cookies.join(';')]
+  end
+end

test/cask/download_strategy_test.rb

@@ -0,0 +1,43 @@
+require 'test_helper'
+require 'download_strategy'
+
+describe Cask::DownloadStrategy do
+  class StubbedDownloadStrategy < Cask::DownloadStrategy
+    def curl(*args)
+      args
+    end
+  end
+
+  before do
+    @resource = Class.new
+    @resource.stubs(:url).returns('example.com')
+    @resource.stubs(:version).returns('3.1')
+  end
+
+  it 'provides user_agent options down to curl' do
+    cask = Cask.load('with-headers')
+    downloader = StubbedDownloadStrategy.new(cask, @resource)
+
+    downloader._fetch.must_include '-A'
+    downloader._fetch.must_include 'Mozilla/25.0.1'
+    downloader.must_respond_to :headers
+  end
+
+  it 'provides :cookie options down to curl' do
+    cask = Cask.load('with-cookies')
+    downloader = StubbedDownloadStrategy.new(cask, @resource)
+
+    downloader._fetch.must_include '-b'
+    downloader._fetch.must_include 'cookie_key=cookie_value'
+    downloader.must_respond_to :headers
+  end
+
+  it 'provides :fake_user_agent options down to curl' do
+    cask = Cask.load('with-fake-user-agent')
+    downloader = StubbedDownloadStrategy.new(cask, @resource)
+
+    downloader._fetch.must_include '-A'
+    downloader._fetch.must_include 'Chrome/32.0.1000.00'
+    downloader.must_respond_to :headers
+  end
+end

test/cask/dsl_test.rb

@@ -84,4 +84,29 @@ def caveats; <<-EOS.undent
     instance = CaskWithInstallables.new
     Array(instance.artifacts[:install]).sort.must_equal %w[Bar.pkg Foo.pkg]
   end
+
+  it 'allows :user_agent to be specified via headers' do
+    options = { user_agent: 'Mozilla/25.0.1' }
+    test_cask = Cask.load('with-headers')
+
+    test_cask.headers.headers.must_equal options
+    test_cask.headers.user_agent.must_equal options[:user_agent]
+  end
+
+  it 'allows :cookies to be specified via headers' do
+    options = { cookies: { cookie_key: 'cookie_value' } }
+    test_cask = Cask.load('with-cookies')
+
+    test_cask.headers.headers.must_equal options
+    test_cask.headers.cookies.must_equal options[:cookies]
+  end
+
+  it 'configures a default fake :user_agent via fake_user_agent' do
+    options = { :user_agent => 'Chrome/32.0.1000.00' }
+    test_cask = Cask.load('with-fake-user-agent')
+
+    test_cask.headers.headers.must_equal options
+    test_cask.headers.user_agent.must_equal options[:user_agent]
+    test_cask.fake_user_agent.must_be_instance_of Cask::Headers
+  end
 end

test/cask/headers_test.rb

@@ -0,0 +1,36 @@
+require 'test_helper'
+
+describe Cask::Headers do
+  describe '#headers' do
+    it 'returns header options' do
+      options  = { :user_agent => 'Netscape/1.0.1',
+                   :cookies    => { :cookey => 'nom_nom' } }
+      instance = Cask::Headers.new(options)
+
+      instance.headers.must_equal options
+      instance.user_agent.must_equal options[:user_agent]
+      instance.cookies.must_equal options[:cookies]
+      instance.cookies[:cookey].must_equal options[:cookies][:cookey]
+    end
+  end
+
+  describe '#user_agent' do
+    it 'returns user_agent' do
+      options  = { user_agent: 'Mozilla/25.0.1' }
+      instance = Cask::Headers.new(options)
+
+      instance.headers.must_equal options
+      instance.user_agent.must_equal options[:user_agent]
+    end
+  end
+
+  describe '#cookies' do
+    it 'returns cookies' do
+      options  = { cookies: { cookey: 'nom_nom' } }
+      instance = Cask::Headers.new(options)
+
+      instance.headers.must_equal options
+      instance.cookies.must_equal options[:cookies]
+    end
+  end
+end

test/support/Casks/with-cookies.rb

@@ -0,0 +1,8 @@
+class WithCookies < TestCask
+  url 'http://example.com/file.dmg'
+  headers :cookies => { :cookie_key => 'cookie_value' }
+  homepage 'http://example.com/'
+  version '3.2'
+  sha1 '5a35b6d47150b60e0cf6892bfa7a37a9f9f30d76'
+  link 'Mac.app'
+end

test/support/Casks/with-fake-user-agent.rb

@@ -0,0 +1,8 @@
+class WithFakeUserAgent < TestCask
+  url 'http://example.com/file.dmg'
+  fake_user_agent
+  homepage 'http://example.com/'
+  version '3.2'
+  sha1 '5a35b6d47150b60e0cf6892bfa7a37a9f9f30d76'
+  link 'Mac.app'
+end

test/support/Casks/with-headers.rb

@@ -0,0 +1,8 @@
+class WithHeaders < TestCask
+  url 'http://example.com/file.dmg'
+  headers :user_agent => 'Mozilla/25.0.1'
+  homepage 'http://example.com/'
+  version '3.2'
+  sha1 '5a35b6d47150b60e0cf6892bfa7a37a9f9f30d76'
+  link 'Mac.app'
+end