Fix mapping over procs

lib/liquid/standardfilters.rb

@@ -101,11 +101,12 @@ module Liquid
     def map(input, property)
       ary = [input].flatten
       ary.map do |e|
-        if e.respond_to?(:to_liquid)
+        e = e.call if e.is_a?(Proc)
-          e = e.to_liquid
+        e = e.to_liquid if e.respond_to?(:to_liquid)
-        end
 
-        if e.respond_to?('[]')
+        if property == "to_liquid"
+          e
+        elsif e.respond_to?(:[])
           e[property]
         end
       end

test/liquid/standard_filter_test.rb

@@ -6,6 +6,27 @@ class Filters
   include Liquid::StandardFilters
 end
 
+class TestThing
+  def initialize
+    @foo = 0
+  end
+
+  def to_s
+    "woot: #{@foo}"
+  end
+
+  def to_liquid
+    @foo += 1
+    self
+  end
+end
+
+class TestDrop < Liquid::Drop
+  def test
+    "testfoo"
+  end
+end
+
 class StandardFiltersTest < Test::Unit::TestCase
   include Liquid
 
@@ -102,6 +123,18 @@ class StandardFiltersTest < Test::Unit::TestCase
     assert_equal "", Liquid::Template.parse('{{ "foo" | map: "inspect" }}').render
   end
 
+  def test_map_calls_to_liquid
+    t = TestThing.new
+    assert_equal "woot: 1", Liquid::Template.parse('{{ foo }}').render("foo" => t)
+  end
+
+  def test_map_over_proc
+    drop = TestDrop.new
+    p = Proc.new{ drop }
+    templ = '{{ procs | map: "test" }}'
+    assert_equal "testfoo", Liquid::Template.parse(templ).render("procs" => [p])
+  end
+
   def test_date
     assert_equal 'May', @filters.date(Time.parse("2006-05-05 10:00:00"), "%B")
     assert_equal 'June', @filters.date(Time.parse("2006-06-05 10:00:00"), "%B")