Improved bundles check to traverse all parent bundles and pretty print the tree path that involves main.js and vue.esm.jsadd-bundle-linter-to-check-for-vue-in-main

3 files changed, 81 insertions, 10 deletions

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index b4c7ec06399..e483f8d448e 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -409,8 +409,7 @@ rake gitlab:assets:compile:
     SKIP_STORAGE_VALIDATION: "true"
     WEBPACK_REPORT: "true"
   script:
-    - bundle exec rake yarn:install gitlab:assets:compile
-    - bundle exec rake lint:js_bundles
+    - bundle exec rake yarn:install gitlab:assets:compile lint:js_bundles
   artifacts:
     name: webpack-report
     expire_in: 31d
diff --git a/lib/tasks/js_bundles_check.rake b/lib/tasks/js_bundles_check.rake
index c90b1dab114..4cb82e076fd 100644
--- a/lib/tasks/js_bundles_check.rake
+++ b/lib/tasks/js_bundles_check.rake
@@ -2,11 +2,85 @@ require 'json'
 
 desc 'GitLab | Check JavaScript bundle files for suboptimal bundling'
 task :js_bundles_check do
-  bundle_stats_file = File.read('./webpack-report/stats.json')
-  bundle_stats = JSON.parse(bundle_stats_file)
+  js_bundle_checker = JsBundleChecker.new('./webpack-report/stats.json')
 
-  vue_module = bundle_stats['modules'].find { |bundle_module| bundle_module['identifier'].end_with?('vue.esm.js') }
-  main_bundle = bundle_stats['chunks'].find { |chunk| chunk['names'].include?('main') }
+  causal_factor_tree, target_node = js_bundle_checker.check_chunk_for('main', './app/assets/javascripts/main.js', './~/vue/dist/vue.esm.js')
 
-  abort('vue.esm.js found within main.js') if vue_module['chunks'].include?(main_bundle['id'])
+  next if causal_factor_tree.nil?
+
+  abort("\n\nvue.esm.js module found within main.js bundle.\n\n#{target_node[:dependency_text]}\n\n")
+end
+
+class JsBundleChecker
+  def initialize(stats_file)
+    @stats_file = stats_file
+  end
+
+  def check_chunk_for(chunk_name, bundle_name, module_name)
+    parse_bundle_stats
+
+    chunk = find_chunk(chunk_name)
+    the_module = find_module(module_name)
+
+    return [nil, nil] unless is_module_in_chunk?(chunk, the_module)
+
+    build_causal_factor_tree(the_module, bundle_name)
+  end
+
+  def is_module_in_chunk?(chunk, the_module)
+    the_module['chunks'].include?(chunk['id'])
+  end
+
+  private
+
+  def parse_bundle_stats
+    bundle_stats_file = File.read(@stats_file)
+
+    @bundle_stats = JSON.parse(bundle_stats_file)
+  end
+
+  def find_module(module_name)
+    @bundle_stats['modules'].find { |bundle_module| bundle_module['name'] == module_name }
+  end
+
+  def find_chunk(chunk_name)
+    @bundle_stats['chunks'].find { |chunk| chunk['names'].include?(chunk_name) }
+  end
+
+  def build_causal_factor_tree(root_module, target_bundle_name)
+    root = create_node(root_module)
+
+    build_parent_nodes(root, target_bundle_name)
+  end
+
+  def build_parent_nodes(current_node, target_bundle_name, target_node = nil)
+    current_node[:module]['reasons'].each do |parent|
+      parent_module = find_module(parent['moduleName'])
+
+      parent_node = create_node(parent_module, current_node)
+
+      target_node = parent_node if parent_node[:name] == target_bundle_name
+
+      parent_node, target_node = build_parent_nodes(parent_node, target_bundle_name, target_node)
+
+      current_node[:parents] = current_node[:parents].push(parent_node)
+    end
+
+    [current_node, target_node]
+  end
+
+  def create_node(the_module, child_module = nil)
+    {
+      name: the_module['name'],
+      module: the_module,
+      parents: [],
+      dependency_text: get_dependency_text(the_module, child_module)
+    }
+  end
+
+  def get_dependency_text(parent_module, child_module)
+    return parent_module['name'] if child_module.nil?
+
+    "#{parent_module['name']}\n            ↑\n#{child_module[:dependency_text]}"
+  end
 end
diff --git a/lib/tasks/lint.rake b/lib/tasks/lint.rake
index a6f2602a88f..cb170f2684e 100644
--- a/lib/tasks/lint.rake
+++ b/lib/tasks/lint.rake
@@ -6,8 +6,6 @@ unless Rails.env.production?
     end
 
     desc 'GitLab | lint | Check JavaScript bundle files for suboptimal bundling'
-    task :js_bundles do
-      Rake::Task['js_bundles_check'].invoke
-    end
+    task js_bundles: ['rake:js_bundles_check']
   end
 end