Refactor Requirement.expand

Library/Homebrew/requirement.rb

@@ -120,12 +120,13 @@ class Requirement
     end
   end
 
+  class << self
     # Expand the requirements of dependent recursively, optionally yielding
     # [dependent, req] pairs to allow callers to apply arbitrary filters to
     # the list.
     # The default filter, which is applied when a block is not given, omits
     # optionals and recommendeds based on what the dependent has asked for.
-  def self.expand(dependent, &block)
+    def expand(dependent, &block)
       reqs = ComparableSet.new
 
       formulae = dependent.recursive_dependencies.map(&:to_formula)
@@ -133,26 +134,18 @@ class Requirement
 
       formulae.map(&:requirements).each do |requirements|
         requirements.each do |req|
-        prune = catch(:prune) do
-          if block_given?
-            yield dependent, req
-          elsif req.optional? || req.recommended?
-            Requirement.prune unless dependent.build.with?(req.name)
-          end
-        end
-
-        next if prune
-
+          if prune?(dependent, req, &block)
+            next
           # TODO: Do this in a cleaner way, perhaps with another type of
           # dependency type.
-        if req.class.default_formula
+          elsif req.class.default_formula
             dependent.class.depends_on(req.class.default_formula)
             next
-        end
-
+          else
             reqs << req
           end
         end
+      end
 
       # We special case handling of X11Dependency and its subclasses to
       # ensure the correct dependencies are present in the final list.
@@ -172,8 +165,19 @@ class Requirement
       reqs
     end
 
+    def prune?(dependent, req, &block)
+      catch(:prune) do
+        if block_given?
+          yield dependent, req
+        elsif req.optional? || req.recommended?
+          prune unless dependent.build.with?(req.name)
+        end
+      end
+    end
+
     # Used to prune requirements when calling expand with a block.
-  def self.prune
+    def prune
       throw(:prune, true)
     end
+  end
 end