Merge pull request #1676 from Shopify/tablerow-nil-params

raise invalid integer argument error from tablerow

lib/liquid/tags/table_row.rb

@@ -45,13 +45,13 @@ module Liquid
     def render_to_output_buffer(context, output)
       (collection = context.evaluate(@collection_name)) || (return '')
 
-      from = @attributes.key?('offset') ? context.evaluate(@attributes['offset']).to_i : 0
+      from = @attributes.key?('offset') ? to_integer(context.evaluate(@attributes['offset'])) : 0
-      to   = @attributes.key?('limit')  ? from + context.evaluate(@attributes['limit']).to_i : nil
+      to = @attributes.key?('limit') ? from + to_integer(context.evaluate(@attributes['limit'])) : nil
 
       collection = Utils.slice_collection(collection, from, to)
       length     = collection.length
 
-      cols = @attributes.key?('cols') ? context.evaluate(@attributes['cols']).to_i : length
+      cols = @attributes.key?('cols') ? to_integer(context.evaluate(@attributes['cols'])) : length
 
       output << "<tr class=\"row1\">\n"
       context.stack do
@@ -82,6 +82,14 @@ module Liquid
         super + @node.attributes.values + [@node.collection_name]
       end
     end
+
+    private
+
+    def to_integer(value)
+      value.to_i
+    rescue NoMethodError
+      raise Liquid::ArgumentError, "invalid integer"
+    end
   end
 
   Template.register_tag('tablerow', TableRow)

test/integration/tags/table_row_test.rb

@@ -80,6 +80,32 @@ class TableRowTest < Minitest::Test
       { "var" => nil })
   end
 
+  def test_nil_limit_is_treated_as_zero
+    expect = "<tr class=\"row1\">\n" \
+      "</tr>\n"
+
+    assert_template_result(expect,
+      "{% tablerow i in (1..2) limit:nil %}{{ i }}{% endtablerow %}")
+
+    assert_template_result(expect,
+      "{% tablerow i in (1..2) limit:var %}{{ i }}{% endtablerow %}",
+      { "var" => nil })
+  end
+
+  def test_nil_offset_is_treated_as_zero
+    expect = "<tr class=\"row1\">\n" \
+      "<td class=\"col1\">1:false</td>" \
+      "<td class=\"col2\">2:true</td>" \
+      "</tr>\n"
+
+    assert_template_result(expect,
+      "{% tablerow i in (1..2) offset:nil %}{{ i }}:{{ tablerowloop.col_last }}{% endtablerow %}")
+
+    assert_template_result(expect,
+      "{% tablerow i in (1..2) offset:var %}{{ i }}:{{ tablerowloop.col_last }}{% endtablerow %}",
+      { "var" => nil })
+  end
+
   def test_tablerow_loop_drop_attributes
     template = <<~LIQUID.chomp
       {% tablerow i in (1...2) %}
@@ -131,4 +157,24 @@ class TableRowTest < Minitest::Test
 
     assert_template_result(expected_output, template)
   end
+
+  def test_table_row_renders_correct_error_message_for_invalid_parameters
+    assert_template_result(
+      "Liquid error (line 1): invalid integer",
+      '{% tablerow n in (1...10) limit:true %} {{n}} {% endtablerow %}',
+      render_errors: true,
+    )
+
+    assert_template_result(
+      "Liquid error (line 1): invalid integer",
+      '{% tablerow n in (1...10) offset:true %} {{n}} {% endtablerow %}',
+      render_errors: true,
+    )
+
+    assert_template_result(
+      "Liquid error (line 1): invalid integer",
+      '{% tablerow n in (1...10) cols:true %} {{n}} {% endtablerow %}',
+      render_errors: true,
+    )
+  end
 end