WIP: Loom

test/unit/eager_optimize_test.rb

@@ -0,0 +1,114 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class EagerOptimizeTest < Minitest::Test
+  include Liquid
+
+  def test_remove_empty_blocks
+    source = <<~LIQUID.gsub(/\n/, '')
+      {% for i in (1..1000000) %}
+      {% endfor %}
+    LIQUID
+
+    template = Liquid::Template.parse(source, eager_optimize: true)
+    assert_equal(0, total_node_count(template))
+  end
+
+  def test_remove_false_if_block
+    source = <<~LIQUID.gsub(/\n/, '')
+      {% if false %}
+        {% if true %}
+          {% if true %}
+            {% if true %}
+              {{ "Hello world!" }}
+            {% endif %}
+          {% endif %}
+        {% endif %}
+      {% endif %}
+    LIQUID
+
+    template = Liquid::Template.parse(source, eager_optimize: true)
+    assert_equal(0, total_node_count(template))
+
+    source = <<~LIQUID.gsub(/\n/, '')
+      {% if false %}
+        {% for i in (1..1000000) %}
+          {{ "Hello world!" }}
+        {% endfor %}
+      {% endif %}
+    LIQUID
+
+    template = Liquid::Template.parse(source, eager_optimize: true)
+    assert_equal(0, total_node_count(template))
+  end
+
+  def test_remove_multiple_false_if_block
+    source = <<~LIQUID.gsub(/\n/, '')
+      {% if false %}
+        {% if true %}
+          {% if true %}
+            {% if true %}
+              {{ "Hello world!" }}
+            {% endif %}
+          {% endif %}
+        {% endif %}
+      {% endif %}
+    LIQUID
+
+    template = Liquid::Template.parse(source, eager_optimize: true)
+    assert_equal(0, total_node_count(template))
+  end
+
+  def test_merge_if_blocks
+    # for now, work with consecutive if blocks without any String nodes in between
+    source = <<~LIQUID.gsub(/\n/, '')
+      {% assign foo = 1 %}
+      {% if foo == 1 %}
+        foo: {{ foo }}
+      {% endif %}
+      {% if foo == 2 %}
+        foo: {{ foo }}
+      {% endif %}
+      {% if foo == 3 %}
+        foo: {{ foo }}
+      {% endif %}
+    LIQUID
+
+    original_template = Liquid::Template.parse(source, eager_optimize: false)
+    template = Template.parse(source, eager_optimize: true)
+
+    assert_equal(
+      [Liquid::Assign, Liquid::If],
+      template.root.nodelist.map(&:class),
+    )
+
+    [nil, 1, 2, 3, 4].each do |foo|
+      assert_equal(
+        original_template.render('foo' => foo),
+        template.render('foo' => foo),
+      )
+    end
+  end
+
+  private
+
+  def total_node_count(template)
+    root = template.root
+    children = root.nodelist
+    count = 0
+
+    while children.any?
+      next_children = []
+
+      children.each do |node|
+        count += 1 unless node.is_a?(Liquid::BlockBody)
+        next_children.concat(node.nodelist) if node.respond_to?(:nodelist) && node.nodelist
+      end
+
+      children = next_children
+    end
+
+    count
+  end
+end