Resolves #529. Resolves #404. Added natural sorting filter and tests.

lib/liquid/standardfilters.rb

@@ -122,6 +122,27 @@ module Liquid
       end
     end
 
+    # Sort elements of an array ignoring case if strings
+    # provide optional property with which to sort an array of hashes or drops
+    def sort_natural(input, property = nil)
+      ary = InputIterator.new(input)
+
+      # Quick function that returns the downcased object if it has a downcase,
+      # otherwise it returns the object itself.
+      insensitive = lambda do |obj|
+        obj = obj.downcase if obj.respond_to? :downcase
+        obj
+      end
+
+      if property.nil?
+        ary.sort {|a,b| insensitive.call(a) <=> insensitive.call(b) }
+      elsif ary.first.respond_to?(:[]) && !ary.first[property].nil?
+        ary.sort {|a,b| insensitive.call(a[property]) <=> insensitive.call(b[property]) }
+      elsif ary.first.respond_to?(property)
+        ary.sort {|a,b| insensitive.call(a.send(property)) <=> insensitive.call(b.send(property)) }
+      end
+    end
+
     # Remove duplicate elements from an array
     # provide optional property with which to determine uniqueness
     def uniq(input, property = nil)

test/integration/filter_test.rb

@@ -74,11 +74,38 @@ class FiltersTest < Minitest::Test
     @context['numbers'] = [2,1,4,3]
     @context['words'] = ['expected', 'as', 'alphabetic']
     @context['arrays'] = ['flower', 'are']
+    @context['case_sensitive'] = ['sensitive', 'Expected', 'case']
 
     assert_equal [1,2,3,4], Variable.new("numbers | sort").render(@context)
     assert_equal ['alphabetic', 'as', 'expected'], Variable.new("words | sort").render(@context)
     assert_equal [3], Variable.new("value | sort").render(@context)
     assert_equal ['are', 'flower'], Variable.new("arrays | sort").render(@context)
+    assert_equal ['Expected', 'case', 'sensitive'], Variable.new("case_sensitive | sort").render(@context)
+  end
+
+  def test_sort_natural
+    @context['value'] = 3
+    @context['numbers'] = [2,1,4,3]
+    @context['words'] = ['case', 'Assert', 'Insensitive']
+    # This specific syntax forces hashes to have string keys. Colons won't work.
+    @context['hashes'] = [{ 'a' => 'A'}, { 'a' => 'b'}, { 'a' => 'C' }]
+    @context['objects'] = [TestObject.new('A'), TestObject.new('b'), TestObject.new('C')]
+
+    assert_equal [1,2,3,4], Variable.new("numbers | sort_natural").render(@context)
+    assert_equal ['Assert', 'case', 'Insensitive'], Variable.new("words | sort_natural").render(@context)
+    assert_equal [3], Variable.new("value | sort_natural").render(@context)
+
+    # Test hashes
+    sorted = Variable.new("hashes | sort_natural: 'a'").render(@context)
+    assert_equal sorted[0]['a'], 'A'
+    assert_equal sorted[1]['a'], 'b'
+    assert_equal sorted[2]['a'], 'C'
+
+    # Test objects
+    sorted = Variable.new("objects | sort_natural: 'a'").render(@context)
+    assert_equal sorted[0].a, 'A'
+    assert_equal sorted[1].a, 'b'
+    assert_equal sorted[2].a, 'C'
   end
 
   def test_strip_html
@@ -136,3 +163,12 @@ class FiltersInTemplate < Minitest::Test
     assert_equal " 1000$ CAD ", Template.parse("{{1000 | money}}").render!(nil, [CanadianMoneyFilter])
   end
 end # FiltersTest
+
+# Simple object that may be passed into a filter.
+# Note to test subjects: do not smuggle test objects out of the testing area.
+class TestObject
+  attr_accessor :a
+  def initialize(a)
+    @a = a
+  end
+end