Update readme

Render tag styling fixes

Gemfile

@@ -20,6 +20,6 @@ group :test do
   gem 'rubocop-performance', require: false
 
   platform :mri, :truffleruby do
-    gem 'liquid-c', github: 'Shopify/liquid-c', ref: 'liquid-tag'
+    gem 'liquid-c', github: 'Shopify/liquid-c', ref: 'master'
   end
 end

README.md

@@ -106,3 +106,9 @@ template = Liquid::Template.parse("{{x}} {{y}}")
 template.render!({ 'x' => 1}, { strict_variables: true })
 #=> Liquid::UndefinedVariable: Liquid error: undefined variable y
 ```
+
+### Usage tracking
+
+To help track usages of a feature or code path in production, we have released opt-in usage tracking. To enable this, we provide an empty `Liquid:: Usage.increment` method which you can customize to your needs. The feature is well suited to https://github.com/Shopify/statsd-instrument. However, the choice of implementation is up to you.
+
+Once you have enabled usage tracking, we recommend reporting any events through Github Issues that your system may be logging. It is highly likely this event has been added to consider deprecating or improving code specific to this event, so please raise any concerns.

lib/liquid.rb

@@ -75,6 +75,7 @@ require 'liquid/utils'
 require 'liquid/tokenizer'
 require 'liquid/parse_context'
 require 'liquid/partial_cache'
+require 'liquid/usage'
 
 # Load all the tags of the standard library
 #

lib/liquid/standardfilters.rb

@@ -421,6 +421,7 @@ module Liquid
 
     def default(input, default_value = ''.freeze)
       if !input || input.respond_to?(:empty?) && input.empty?
+        Usage.increment("default_filter_received_false_value") if input == false # See https://github.com/Shopify/liquid/issues/1127
         default_value
       else
         input

lib/liquid/tags/render.rb

@@ -1,13 +1,13 @@
 module Liquid
   class Render < Tag
-    Syntax = /(#{QuotedString})#{QuotedFragment}*/o
+    SYNTAX = /(#{QuotedString})#{QuotedFragment}*/o
 
     attr_reader :template_name_expr, :attributes
 
     def initialize(tag_name, markup, options)
       super
 
-      raise SyntaxError.new(options[:locale].t("errors.syntax.render".freeze)) unless markup =~ Syntax
+      raise SyntaxError.new(options[:locale].t("errors.syntax.render".freeze)) unless markup =~ SYNTAX
 
       template_name = $1
 

lib/liquid/usage.rb

@@ -0,0 +1,6 @@
+module Liquid
+  module Usage
+    def self.increment(name)
+    end
+  end
+end

test/integration/tags/render_tag_test.rb

@@ -110,7 +110,7 @@ class RenderTagTest < Minitest::Test
     file_system = StubFileSystem.new('snippet' => 'echo')
     assert_equal 'echoecho',
       Template.parse('{% render "snippet" %}{% render "snippet" %}')
-              .render!({}, registers: { file_system: file_system })
+      .render!({}, registers: { file_system: file_system })
     assert_equal 1, file_system.file_read_count
   end
 

test/unit/partial_cache_unit_test.rb

@@ -4,7 +4,7 @@ class PartialCacheUnitTest < Minitest::Test
   def test_uses_the_file_system_register_if_present
     context = Liquid::Context.build(
       registers: {
-        file_system: StubFileSystem.new('my_partial' => 'my partial body')
+        file_system: StubFileSystem.new('my_partial' => 'my partial body'),
       }
     )
 
@@ -41,12 +41,12 @@ class PartialCacheUnitTest < Minitest::Test
     )
     context_one = Liquid::Context.build(
       registers: {
-        file_system: shared_file_system
+        file_system: shared_file_system,
       }
     )
     context_two = Liquid::Context.build(
       registers: {
-        file_system: shared_file_system
+        file_system: shared_file_system,
       }
     )