Refactor the Optimizer class no visit the AST

Just takes care of Variables for now.

Increases performance.

.github/workflows/liquid.yml

@@ -1,40 +0,0 @@
-name: Liquid
-on: [push]
-jobs:
-  test:
-    runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        entry:
-          - { ruby: 2.5, allowed-failure: false }
-          - { ruby: 2.6, allowed-failure: false }
-          - { ruby: 2.7, allowed-failure: false }
-          - { ruby: ruby-head, allowed-failure: true }
-    name: test (${{ matrix.entry.ruby }})
-    steps:
-      - uses: actions/checkout@v2
-      - uses: ruby/setup-ruby@v1
-        with:
-          ruby-version: ${{ matrix.entry.ruby }}
-      - uses: actions/cache@v1
-        with:
-          path: vendor/bundle
-          key: ${{ runner.os }}-gems-${{ hashFiles('Gemfile') }}
-          restore-keys: ${{ runner.os }}-gems-
-      - run: bundle install --jobs=3 --retry=3 --path=vendor/bundle
-      - run: bundle exec rake
-        continue-on-error: ${{ matrix.entry.allowed-failure }}
-  memory_profile:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - uses: ruby/setup-ruby@v1
-        with:
-          ruby-version: 2.7
-      - uses: actions/cache@v1
-        with:
-          path: vendor/bundle
-          key: ${{ runner.os }}-gems-${{ hashFiles('Gemfile') }}
-          restore-keys: ${{ runner.os }}-gems-
-      - run: bundle install --jobs=3 --retry=3 --path=vendor/bundle
-      - run: bundle exec rake memory_profile:run

.travis.yml

@@ -0,0 +1,26 @@
+language: ruby
+cache: bundler
+
+rvm:
+  - 2.4
+  - 2.5
+  - 2.6
+  - &latest_ruby 2.7
+  - ruby-head
+
+matrix:
+  include:
+    - rvm: *latest_ruby
+      script: bundle exec rake memory_profile:run
+      name: Profiling Memory Usage
+  allow_failures:
+    - rvm: ruby-head
+
+branches:
+  only:
+    - master
+    - gh-pages
+    - /.*-stable/
+
+notifications:
+  disable: true

Rakefile

@@ -9,17 +9,11 @@ task(default: [:test, :rubocop])
 
 desc('run test suite with default parser')
 Rake::TestTask.new(:base_test) do |t|
-  t.libs << 'lib' << 'test'
+  t.libs << '.' << 'lib' << 'test'
   t.test_files = FileList['test/{integration,unit}/**/*_test.rb']
   t.verbose    = false
 end
 
-Rake::TestTask.new(:integration_test) do |t|
-  t.libs << 'lib' << 'test'
-  t.test_files = FileList['test/integration/**/*_test.rb']
-  t.verbose    = false
-end
-
 desc('run test suite with warn error mode')
 task :warn_test do
   ENV['LIQUID_PARSER_MODE'] = 'warn'
@@ -46,12 +40,12 @@ task :test do
     ENV['LIQUID_C'] = '1'
 
     ENV['LIQUID_PARSER_MODE'] = 'lax'
-    Rake::Task['integration_test'].reenable
-    Rake::Task['integration_test'].invoke
+    Rake::Task['base_test'].reenable
+    Rake::Task['base_test'].invoke
 
     ENV['LIQUID_PARSER_MODE'] = 'strict'
-    Rake::Task['integration_test'].reenable
-    Rake::Task['integration_test'].invoke
+    Rake::Task['base_test'].reenable
+    Rake::Task['base_test'].invoke
   end
 end
 

lib/liquid.rb

@@ -84,6 +84,7 @@ require 'liquid/usage'
 require 'liquid/register'
 require 'liquid/static_registers'
 require 'liquid/template_factory'
+require 'liquid/optimizer'
 
 # Load all the tags of the standard library
 #

lib/liquid/optimizer.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+module Liquid
+  class Optimizer
+    class << self
+      attr_accessor :enabled
+
+      def optimize_variable(node)
+        return unless enabled
+
+        # Turn chained `| append: "..."| append: "..."`, into a single `append_all: [...]`
+        if node.filters.size > 1 && node.filters.all? { |f, _| f == "append" }
+          node.filters = [["append_all", node.filters.map { |f, (arg)| arg }]]
+        end
+      end
+    end
+    self.enabled = true
+  end
+end

lib/liquid/standardfilters.rb

@@ -89,21 +89,13 @@ module Liquid
 
     def truncatewords(input, words = 15, truncate_string = "...")
       return if input.nil?
-      words = Utils.to_integer(words)
+      wordlist = input.to_s.split
+      words    = Utils.to_integer(words)
 
-      words = 1 if words <= 0
+      l = words - 1
+      l = 0 if l < 0
 
-      # Scan for non-space characters followed by one or more space characters
-      # `words` times.  Also ignore leading whitespace
-      str = input[/\A[ ]*(?:[^ ]*[ ]+){#{words}}/]
-
-      if str
-        str.strip!                # Remove trailing space
-        str.gsub!(/[ ]{2,}/, " ") # Shrink multiple spaces to one space
-        str.concat(truncate_string.to_s)
-      else
-        input
-      end
+      wordlist.length > l ? wordlist[0..l].join(" ").concat(truncate_string.to_s) : input
     end
 
     # Split input string into an array of substrings separated by given pattern.
@@ -289,6 +281,10 @@ module Liquid
       input.to_s + string.to_s
     end
 
+    def append_all(input, *items)
+      input.to_s + items.join
+    end
+
     def concat(input, array)
       unless array.respond_to?(:to_ary)
         raise ArgumentError, "concat filter requires an array argument"

lib/liquid/variable.rb

@@ -31,6 +31,8 @@ module Liquid
       @line_number   = parse_context.line_number
 
       parse_with_selected_parser(markup)
+
+      Optimizer.optimize_variable(self)
     end
 
     def raw

liquid.gemspec

@@ -17,7 +17,7 @@ Gem::Specification.new do |s|
   s.license     = "MIT"
   # s.description = "A secure, non-evaling end user template engine with aesthetic markup."
 
-  s.required_ruby_version     = ">= 2.5.0"
+  s.required_ruby_version     = ">= 2.4.0"
   s.required_rubygems_version = ">= 1.3.7"
 
   s.test_files  = Dir.glob("{test}/**/*")

test/integration/filter_test.rb

@@ -153,15 +153,6 @@ class FiltersTest < Minitest::Test
     # tap still treated as a non-existent filter
     assert_equal("1000", Template.parse("{{var | tap}}").render!('var' => 1000))
   end
-
-  def test_liquid_argument_error
-    source = "{{ '' | size: 'too many args' }}"
-    exc = assert_raises(Liquid::ArgumentError) do
-      Template.parse(source).render!
-    end
-    assert_match(/\ALiquid error: wrong number of arguments /, exc.message)
-    assert_equal(exc.message, Template.parse(source).render)
-  end
 end
 
 class FiltersInTemplate < Minitest::Test

test/integration/standard_filter_test.rb

@@ -168,8 +168,6 @@ class StandardFiltersTest < Minitest::Test
   def test_truncatewords
     assert_equal('one two three', @filters.truncatewords('one two three', 4))
     assert_equal('one two...', @filters.truncatewords('one two three', 2))
-    assert_equal('one two...', @filters.truncatewords('one     two three', 2))
-    assert_equal('one two...', @filters.truncatewords('   one     two three', 2))
     assert_equal('one two three', @filters.truncatewords('one two three'))
     assert_equal(
       'Two small (13&#8221; x 5.5&#8221; x 10&#8221; high) baskets fit inside one large basket (13&#8221;...',
@@ -177,8 +175,6 @@ class StandardFiltersTest < Minitest::Test
     )
     assert_equal("测试测试测试测试", @filters.truncatewords('测试测试测试测试', 5))
     assert_equal('one two1', @filters.truncatewords("one two three", 2, 1))
-    assert_equal('one1', @filters.truncatewords("one two three", 0, 1))
-    assert_equal('one1', @filters.truncatewords("one two three", -1, 1))
   end
 
   def test_strip_html

test/unit/optimizer_test.rb

@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class OptimizerUnitTest < Minitest::Test
+  include Liquid
+
+  def test_combines_append_filters
+    optimizer = Optimizer.new
+    var = Variable.new('hello | append: "a" | append: b', ParseContext.new)
+    var = optimizer.optimize(var)
+    assert_equal([
+      ['append_all', ["a", VariableLookup.new("b")]]
+    ], var.filters)
+  end
+end