Add variable_name_expr to render's ParseTreeVisitor

Solves Shopify/theme-check#582

`icon` should be visited in the render tag for the following snippet:

```liquid
{% assign icon = 'warning' }
{% render 'icon' with icon %}
```

History.md

@@ -11,6 +11,7 @@
 ### Fixes
 * `PartialCache` now shares snippet cache with subcontexts by default (#1553) [Chris AtLee]
 * Hash registers no longer leak into subcontexts as static registers (#1564) [Chris AtLee]
+* Fix `ParseTreeVisitor` for `with` variable expressions in `Render` tag (#1596) [CP Clermont]
 
 ### Changed
 * Liquid::Context#registers now always returns a Liquid::Registers object, though supports the most used Hash functions for compatibility (#1553)

lib/liquid/standardfilters.rb

@@ -358,7 +358,11 @@ module Liquid
     # @liquid_type filter
     # @liquid_category array
     # @liquid_summary
-    #   Sorts the items in an array in case-insensitive alphabetical, or numerical, order.
+    #   Sorts the items in an array in case-insensitive alphabetical order.
+    # @liquid_description
+    #   > Caution:
+    #   > You shouldn't use the `sort_natural` filter to sort numerical values. When comparing items an array, each item is converted to a
+    #   > string, so sorting on numerical values can lead to unexpected results.
     # @liquid_syntax array | sort_natural
     # @liquid_return [array[untyped]]
     def sort_natural(input, property = nil)

lib/liquid/tags/render.rb

@@ -31,7 +31,7 @@ module Liquid
 
     disable_tags "include"
 
-    attr_reader :template_name_expr, :attributes
+    attr_reader :template_name_expr, :variable_name_expr, :attributes
 
     def initialize(tag_name, markup, options)
       super
@@ -99,6 +99,7 @@ module Liquid
       def children
         [
           @node.template_name_expr,
+          @node.variable_name_expr,
         ] + @node.attributes.values
       end
     end

lib/liquid/tags/unless.rb

@@ -15,7 +15,7 @@ module Liquid
   # @liquid_syntax
   #   {% unless condition %}
   #     expression
-  #   {% endif %}
+  #   {% endunless %}
   # @liquid_syntax_keyword condition The condition to evaluate.
   # @liquid_syntax_keyword expression The expression to render unless the condition is met.
   class Unless < If

lib/liquid/variable_lookup.rb

@@ -32,6 +32,10 @@ module Liquid
       end
     end
 
+    def lookup_command?(lookup_index)
+      @command_flags & (1 << lookup_index) != 0
+    end
+
     def evaluate(context)
       name   = context.evaluate(@name)
       object = context.find_variable(name)
@@ -55,7 +59,7 @@ module Liquid
           # Some special cases. If the part wasn't in square brackets and
           # no key with the same name was found we interpret following calls
           # as commands and call them on the current object
-        elsif @command_flags & (1 << i) != 0 && object.respond_to?(key)
+        elsif lookup_command?(i) && object.respond_to?(key)
           object = object.send(key).to_liquid
 
           # No key was present with the desired value and it wasn't one of the directly supported

test/unit/parse_tree_visitor_test.rb

@@ -236,6 +236,20 @@ class ParseTreeVisitorTest < Minitest::Test
     )
   end
 
+  def test_render_with
+    assert_equal(
+      ["test"],
+      visit(%({% render "hai" with test %}))
+    )
+  end
+
+  def test_render_for
+    assert_equal(
+      ["test"],
+      visit(%({% render "hai" for test %}))
+    )
+  end
+
   def test_preserve_tree_structure
     assert_equal(
       [[nil, [