Merge pull request #407 from Shopify/slice_arrays

Slice filter for arrays

lib/liquid/standardfilters.rb

@@ -45,8 +45,13 @@ module Liquid
     def slice(input, offset, length=nil)
       offset = Integer(offset)
       length = length ? Integer(length) : 1
+
+      if input.is_a?(Array)
+        input.slice(offset, length) || []
+      else
         input.to_s.slice(offset, length) || ''
       end
+    end
 
     # Truncate a string down to x characters
     def truncate(input, length = 50, truncate_string = "...".freeze)

test/integration/standard_filter_test.rb

@@ -78,6 +78,20 @@ class StandardFiltersTest < Minitest::Test
     assert_equal '', @filters.slice('foobar', -100, 10)
   end
 
+  def test_slice_on_arrays
+    input = 'foobar'.split(//)
+    assert_equal %w{o o b}, @filters.slice(input, 1, 3)
+    assert_equal %w{o o b a r}, @filters.slice(input, 1, 1000)
+    assert_equal %w{}, @filters.slice(input, 1, 0)
+    assert_equal %w{o}, @filters.slice(input, 1, 1)
+    assert_equal %w{b a r}, @filters.slice(input, 3, 3)
+    assert_equal %w{a r}, @filters.slice(input, -2, 2)
+    assert_equal %w{a r}, @filters.slice(input, -2, 1000)
+    assert_equal %w{r}, @filters.slice(input, -1)
+    assert_equal %w{}, @filters.slice(input, 100, 10)
+    assert_equal %w{}, @filters.slice(input, -100, 10)
+  end
+
   def test_truncate
     assert_equal '1234...', @filters.truncate('1234567890', 7)
     assert_equal '1234567890', @filters.truncate('1234567890', 20)