Handle boolean values in sort filter comparison

lib/liquid/standardfilters.rb

@@ -1006,6 +1006,9 @@ def apply_operation(input, operand, operation)
     end
 
     def nil_safe_compare(a, b)
+      a = a ? 1 : 0 if boolean?(a)
+      b = b ? 1 : 0 if boolean?(b)
+
       result = a <=> b
 
       if result
@@ -1029,6 +1032,10 @@ def nil_safe_casecmp(a, b)
       end
     end
 
+    def boolean?(value)
+      value.is_a?(TrueClass) || value.is_a?(FalseClass)
+    end
+
     class InputIterator
       include Enumerable
 

test/integration/standard_filter_test.rb

@@ -305,12 +305,15 @@ def to_liquid
 
   def test_sort
     assert_equal([1, 2, 3, 4], @filters.sort([4, 3, 2, 1]))
+    assert_equal([false, false, true, true], @filters.sort([true, false, true, false]))
     assert_equal([{ "a" => 1 }, { "a" => 2 }, { "a" => 3 }, { "a" => 4 }], @filters.sort([{ "a" => 4 }, { "a" => 3 }, { "a" => 1 }, { "a" => 2 }], "a"))
+    assert_equal([{ "a" => false }, { "a" => false }, { "a" => true }, { "a" => true }], @filters.sort([{ "a" => true }, { "a" => false }, { "a" => true }, { "a" => false }], "a"))
   end
 
   def test_sort_with_nils
     assert_equal([1, 2, 3, 4, nil], @filters.sort([nil, 4, 3, 2, 1]))
     assert_equal([{ "a" => 1 }, { "a" => 2 }, { "a" => 3 }, { "a" => 4 }, {}], @filters.sort([{ "a" => 4 }, { "a" => 3 }, {}, { "a" => 1 }, { "a" => 2 }], "a"))
+    assert_equal([{ "a" => false }, { "a" => false }, { "a" => true }, { "a" => true }, {}], @filters.sort([{ "a" => true }, {}, { "a" => false }, { "a" => true }, { "a" => false }], "a"))
   end
 
   def test_sort_when_property_is_sometimes_missing_puts_nils_last