tap: add cask methods.

Library/Homebrew/cmd/update-report.rb

@@ -193,7 +193,7 @@ class Reporter
       dst = Pathname.new paths.last
 
       next unless dst.extname == ".rb"
-      next unless paths.any? { |p| tap.formula_file?(p)}
+      next unless paths.any? { |p| tap.formula_file?(p) || tap.cask_file?(p)}
 
       case status
       when "A", "D"

Library/Homebrew/tap.rb

@@ -72,6 +72,7 @@ class Tap
   def clear_cache
     @remote = nil
     @formula_dir = nil
+    @cask_dir = nil
     @formula_files = nil
     @alias_dir = nil
     @alias_files = nil
@@ -304,6 +305,11 @@ class Tap
     @formula_dir ||= [path/"Formula", path/"HomebrewFormula", path].detect(&:directory?)
   end
 
+  # path to the directory of all casks for caskroom/cask {Tap}.
+  def cask_dir
+    @cask_dir ||= path/"Casks"
+  end
+
   # an array of all {Formula} files of this {Tap}.
   def formula_files
     @formula_files ||= if formula_dir
@@ -322,6 +328,15 @@ class Tap
     file.extname == ".rb" && file.parent == formula_dir
   end
 
+  # return true if given path would present a cask file in this {Tap}.
+  # accepts both absolute path and relative path (relative to this {Tap}'s path)
+  # @private
+  def cask_file?(file)
+    file = Pathname.new(file) unless file.is_a? Pathname
+    file = file.expand_path(path)
+    file.extname == ".rb" && file.parent == cask_dir
+  end
+
   # an array of all {Formula} names of this {Tap}.
   def formula_names
     @formula_names ||= formula_files.map { |f| formula_file_to_name(f) }