add `gpg` stanza to DSL

For forward compatibility.  The stanza has no effect, and is
intentionally left undocumented at this time.

References: #4688

lib/cask.rb

@@ -21,6 +21,7 @@ require 'cask/download_strategy'
 require 'cask/dsl'
 require 'cask/exceptions'
 require 'cask/fetcher'
+require 'cask/gpg'
 require 'cask/installer'
 require 'cask/link_checker'
 require 'cask/locations'

lib/cask/dsl.rb

@@ -12,6 +12,8 @@ module Cask::DSL
 
   def appcast; self.class.appcast; end
 
+  def gpg; self.class.gpg; end
+
   def version; self.class.version; end
 
   def depends_on_formula; self.class.depends_on_formula; end
@@ -50,6 +52,17 @@ module Cask::DSL
       end
     end
 
+    def gpg(*args)
+      if @gpg and !args.empty?
+        raise CaskInvalidError.new(self.title, "'gpg' stanza may only appear once")
+      end
+      @gpg ||= begin
+        Cask::Gpg.new(*args) unless args.empty?
+      rescue StandardError => e
+        raise CaskInvalidError.new(self.title, e)
+      end
+    end
+
     def container_type(type=nil)
       if @container_type and !type.nil?
         raise CaskInvalidError.new(self.title, "'container_type' stanza may only appear once")

lib/cask/gpg.rb

@@ -0,0 +1,40 @@
+class Cask::Gpg
+
+  VALID_TYPES = Set.new [
+                         :id,   # first one is the default
+                         :url,
+                        ]
+
+  REQUIRED_PARAMETERS = [
+                         :signature
+                        ]
+
+  attr_reader :key, :parameters, :type, :signature
+
+  def initialize(key, parameters={})
+    @parameters = parameters
+    REQUIRED_PARAMETERS.each do |param|
+      unless @parameters.key?(param) and not @parameters[param].nil?
+        raise "gpg #{param.inspect} parameter is required"
+      end
+    end
+    @key       = key
+    @signature = Cask::UnderscoreSupportingURI.parse(@parameters[:signature])
+    @type      = @parameters[:type]
+    @type      = VALID_TYPES.first if @type.nil?
+    unless VALID_TYPES.include?(@type)
+      raise "invalid gpg type: '#{@type.inspect}'"
+    end
+    if @type == :url
+      @key = Cask::UnderscoreSupportingURI.parse(@key)
+    end
+  end
+
+  def to_yaml
+    [@key, @parameters].to_yaml
+  end
+
+  def to_s
+    @key.to_s
+  end
+end

lib/cask/utils.rb

@@ -82,6 +82,7 @@ module Cask::Utils
        :caveats,
        :depends_on_formula,
        :container_type,
+       :gpg,
       ].each do |method|
         odebug "Cask instance method '#{method}':", self.send(method).to_yaml
       end

test/cask/dsl_test.rb

@@ -112,4 +112,36 @@ describe Cask::DSL do
     }.must_raise(CaskInvalidError)
     err.message.must_include "'version' stanza may only appear once"
   end
+
+  describe "gpg stanza" do
+    it "allows gpg stanza to be specified" do
+      cask = Cask.load('with-gpg')
+      cask.gpg.to_s.must_match %r{\S}
+    end
+
+    it "prevents specifying gpg multiple times" do
+      err = lambda {
+        invalid_cask = Cask.load('invalid/invalid-gpg-multiple')
+      }.must_raise(CaskInvalidError)
+      err.message.must_include "'gpg' stanza may only appear once"
+    end
+
+    it "refuses to load invalid gpg signature URLs" do
+      err = lambda {
+        invalid_cask = Cask.load('invalid/invalid-gpg-signature-url')
+      }.must_raise(CaskInvalidError)
+    end
+
+    it "refuses to load invalid gpg key URLs" do
+      err = lambda {
+        invalid_cask = Cask.load('invalid/invalid-gpg-key-url')
+      }.must_raise(CaskInvalidError)
+    end
+
+    it "refuses to load if gpg :type is invalid" do
+      err = lambda {
+        invalid_cask = Cask.load('invalid/invalid-gpg-type')
+      }.must_raise(CaskInvalidError)
+    end
+  end
 end

test/support/Casks/invalid/invalid-gpg-key-url.rb

@@ -0,0 +1,9 @@
+class InvalidGpgKeyUrl < TestCask
+  url TestHelper.local_binary('caffeine.zip')
+  homepage 'http://example.com/invalid-gpg-key-url'
+  gpg 1, :type => :url,
+         :signature => 'http://example.com/gpg-signature.asc'
+  sha256 '9203c30951f9aab41ac294bbeb1dcef7bed401ff0b353dcb34d68af32ea51853'
+  version '1.2.3'
+  link 'Caffeine.app'
+end

test/support/Casks/invalid/invalid-gpg-multiple.rb

@@ -0,0 +1,11 @@
+class InvalidGpgMultiple < TestCask
+  url TestHelper.local_binary('caffeine.zip')
+  homepage 'http://example.com/invalid-gpg-multiple'
+  gpg 'ID', :type => :id,
+            :signature => 'http://example.com/gpg-signature.asc'
+  gpg 'ID', :type => :id,
+            :signature => 'http://example.com/gpg-signature.asc'
+  sha256 '9203c30951f9aab41ac294bbeb1dcef7bed401ff0b353dcb34d68af32ea51853'
+  version '1.2.3'
+  link 'Caffeine.app'
+end

test/support/Casks/invalid/invalid-gpg-signature-url.rb

@@ -0,0 +1,9 @@
+class InvalidGpgSignatureUrl < TestCask
+  url TestHelper.local_binary('caffeine.zip')
+  homepage 'http://example.com/invalid-gpg-signature-url'
+  gpg 'ID', :type => :id,
+            :signature => 1
+  sha256 '9203c30951f9aab41ac294bbeb1dcef7bed401ff0b353dcb34d68af32ea51853'
+  version '1.2.3'
+  link 'Caffeine.app'
+end

test/support/Casks/invalid/invalid-gpg-type.rb

@@ -0,0 +1,9 @@
+class InvalidGpgType < TestCask
+  url TestHelper.local_binary('caffeine.zip')
+  homepage 'http://example.com/invalid-gpg-type'
+  gpg 'ID', :type => :no_such_type,
+            :signature => 'http://example.com/gpg-signature.asc'
+  sha256 '9203c30951f9aab41ac294bbeb1dcef7bed401ff0b353dcb34d68af32ea51853'
+  version '1.2.3'
+  link 'Caffeine.app'
+end

test/support/Casks/with-gpg.rb

@@ -0,0 +1,9 @@
+class WithGpg < TestCask
+  url TestHelper.local_binary('caffeine.zip')
+  homepage 'http://example.com/with-gpg'
+  gpg 'ID', :type => :id,
+            :signature => 'http://example.com/gpg-signature.asc'
+  sha256 '9203c30951f9aab41ac294bbeb1dcef7bed401ff0b353dcb34d68af32ea51853'
+  version '1.2.3'
+  link 'Caffeine.app'
+end