PERF: Update ember-auto-import and webpack (#15919)

This makes a small improvement to 'cold cache' ember-cli build times, and a large improvement to 'warm cache' build times

The ember-auto-import update means that vendor is now split into multiple files for efficiency. These are named `chunk.*`, and should be included immediately after the `vendor.js` file. This commit also updates the rails app to render script tags for these chunks.

This change was previously merged, and caused memory-related errors on RAM-constrained machines. This was because Webpack 5 switches from multiple worker processes to a single multi-threaded process. This meant that it was hitting node's default heap size limit (~500mb on a 1GB RAM server). Discourse's standard install procedure recommends adding 2GB swap to 1GB-RAM machines, so we can afford to override's Node's default via the `--max-old-space-size` flag.

app/assets/javascripts/admin/package.json

@@ -15,10 +15,11 @@
     "start": "ember serve"
   },
   "dependencies": {
-    "ember-auto-import": "^1.5.3",
+    "ember-auto-import": "^2.2.4",
     "ember-cli-babel": "^7.13.0",
     "ember-cli-htmlbars": "^4.2.0",
-    "xss": "^1.0.8"
+    "xss": "^1.0.8",
+    "webpack": "^5.67.0"
   },
   "devDependencies": {
     "@ember/optional-features": "^1.1.0",

app/assets/javascripts/discourse-common/package.json

@@ -15,17 +15,18 @@
     "start": "ember serve"
   },
   "dependencies": {
-    "ember-cli-babel": "^7.13.0",
-    "ember-cli-htmlbars": "^4.2.0",
-    "ember-auto-import": "^1.5.3",
-    "handlebars": "^4.7.0",
-    "truth-helpers": "^1.0.0",
     "@uppy/aws-s3": "^2.0.4",
     "@uppy/aws-s3-multipart": "^2.1.0",
     "@uppy/core": "^2.1.0",
     "@uppy/drop-target": "^1.1.0",
     "@uppy/utils": "^4.0.3",
-    "@uppy/xhr-upload": "^2.0.4"
+    "@uppy/xhr-upload": "^2.0.4",
+    "ember-auto-import": "^2.2.4",
+    "ember-cli-babel": "^7.13.0",
+    "ember-cli-htmlbars": "^4.2.0",
+    "handlebars": "^4.7.0",
+    "truth-helpers": "^1.0.0",
+    "webpack": "^5.67.0"
   },
   "devDependencies": {
     "@ember/optional-features": "^1.1.0",

app/assets/javascripts/discourse-hbr/package.json

@@ -15,9 +15,10 @@
     "start": "ember serve"
   },
   "dependencies": {
-    "ember-auto-import": "^1.5.3",
+    "ember-auto-import": "^2.2.4",
     "ember-cli-babel": "^7.13.0",
-    "ember-cli-htmlbars": "^4.2.0"
+    "ember-cli-htmlbars": "^4.2.0",
+    "webpack": "^5.67.0"
   },
   "devDependencies": {
     "@ember/optional-features": "^1.1.0",

app/assets/javascripts/discourse-widget-hbs/package.json

@@ -15,9 +15,10 @@
     "start": "ember serve"
   },
   "dependencies": {
-    "ember-auto-import": "^1.5.3",
+    "ember-auto-import": "^2.2.4",
     "ember-cli-babel": "^7.13.0",
-    "ember-cli-htmlbars": "^4.2.0"
+    "ember-cli-htmlbars": "^4.2.0",
+    "webpack": "^5.67.0"
   },
   "devDependencies": {
     "@ember/optional-features": "^1.1.0",

app/assets/javascripts/discourse/package.json

@@ -34,7 +34,7 @@
     "discourse-common": "^1.0.0",
     "discourse-hbr": "^1.0.0",
     "discourse-widget-hbs": "^1.0.0",
-    "ember-auto-import": "^1.12.0",
+    "ember-auto-import": "^2.2.4",
     "ember-buffered-proxy": "^2.0.0-beta.0",
     "ember-cli": "~3.25.3",
     "ember-cli-app-version": "^4.0.0",
@@ -44,7 +44,7 @@
     "ember-cli-inject-live-reload": "^2.0.1",
     "ember-cli-sri": "^2.1.1",
     "ember-cli-terser": "^4.0.1",
-    "ember-exam": "6.1.0",
+    "ember-exam": "^7.0.1",
     "ember-export-application-global": "^2.0.1",
     "ember-load-initializers": "^2.1.1",
     "ember-maybe-import-regenerator": "^0.1.6",
@@ -67,7 +67,8 @@
     "sass": "^1.32.8",
     "select-kit": "^1.0.0",
     "sinon": "^9.2.0",
-    "virtual-dom": "^2.1.1"
+    "virtual-dom": "^2.1.1",
+    "webpack": "^5.67.0"
   },
   "engines": {
     "node": "12.* || 14.* || >= 16",
@@ -84,6 +85,6 @@
     ]
   },
   "devDependencies": {
-    "ember-exam": "6.1.0"
+    "ember-exam": "^7.0.1"
   }
 }

app/assets/javascripts/pretty-text/package.json

@@ -15,10 +15,11 @@
     "start": "ember serve"
   },
   "dependencies": {
-    "ember-auto-import": "^1.5.3",
+    "ember-auto-import": "^2.2.4",
     "ember-cli-babel": "^7.13.0",
     "ember-cli-htmlbars": "^4.2.0",
-    "xss": "^1.0.8"
+    "xss": "^1.0.8",
+    "webpack": "^5.67.0"
   },
   "devDependencies": {
     "@ember/optional-features": "^1.1.0",

app/assets/javascripts/select-kit/package.json

@@ -17,7 +17,8 @@
   "dependencies": {
     "ember-cli-babel": "^7.13.0",
     "ember-cli-htmlbars": "^4.2.0",
-    "ember-auto-import": "^1.5.3"
+    "ember-auto-import": "^2.2.4",
+    "webpack": "^5.67.0"
   },
   "devDependencies": {
     "@ember/optional-features": "^1.1.0",

app/assets/javascripts/truth-helpers/package.json

@@ -15,9 +15,10 @@
     "start": "ember serve"
   },
   "dependencies": {
-    "ember-auto-import": "^1.5.3",
+    "ember-auto-import": "^2.2.4",
     "ember-cli-babel": "^7.13.0",
-    "ember-cli-htmlbars": "^4.2.0"
+    "ember-cli-htmlbars": "^4.2.0",
+    "webpack": "^5.67.0"
   },
   "devDependencies": {
     "@ember/optional-features": "^1.1.0",

app/helpers/application_helper.rb

@@ -135,6 +135,22 @@ module ApplicationHelper
     path
   end
 
+  def preload_vendor_scripts
+    scripts = ["vendor"]
+
+    if ENV["EMBER_CLI_PROD_ASSETS"] == "1"
+      @@vendor_chunks ||= begin
+        all_assets = ActionController::Base.helpers.assets_manifest.assets
+        all_assets.keys.filter_map { |name| name[/\A(chunk\..*)\.js\z/, 1] }
+      end
+      scripts.push(*@@vendor_chunks)
+    end
+
+    scripts.map do |name|
+      preload_script(name)
+    end.join("\n").html_safe
+  end
+
   def preload_script(script)
     path = script_asset_path(script)
     preload_script_url(path)

app/helpers/qunit_helper.rb

@@ -4,7 +4,7 @@ module QunitHelper
 
   def vendor_theme_tests
     return preload_script("vendor-theme-tests") if @legacy_ember
-    preload_script("vendor")
+    preload_vendor_scripts
   end
 
   def support_bundles

app/views/layouts/application.html.erb

@@ -29,7 +29,7 @@
     <%- if ExtraLocalesController.client_overrides_exist? %>
       <%= preload_script_url ExtraLocalesController.url('overrides') %>
     <%- end %>
-    <%= preload_script "vendor" %>
+    <%= preload_vendor_scripts %>
     <%= preload_script "application" %>
     <%- Discourse.find_plugin_js_assets(include_official: allow_plugins?, include_unofficial: allow_third_party_plugins?, request: request).each do |file| %>
       <%= preload_script file %>

app/views/qunit/index.html.erb

@@ -6,7 +6,7 @@
     <%= discourse_stylesheet_link_tag(:desktop, theme_id: nil) %>
     <%= discourse_stylesheet_link_tag(:test_helper, theme_id: nil) %>
     <%= preload_script "locales/#{I18n.locale}" %>
-    <%= preload_script "vendor" %>
+    <%= preload_vendor_scripts %>
     <%= preload_script "application" %>
     <%= preload_script "admin" %>
     <%= preload_script "discourse/tests/test-support-rails" %>

app/views/users/activate_account.html.erb

@@ -10,7 +10,7 @@
 </div>
 
 <%- content_for(:no_ember_head) do %>
-  <%= preload_script "vendor" %>
+  <%= preload_vendor_scripts %>
   <%= render_google_universal_analytics_code %>
   <%= tag.meta id: 'data-activate-account', data: { path: path('/session/hp') } %>
 <%- end %>

lib/tasks/assets.rake

@@ -245,7 +245,7 @@ def copy_ember_cli_assets
   files = {}
 
   log_task_duration('ember build -prod') {
-    unless system("yarn --cwd #{ember_dir} run ember build -prod")
+    unless system("NODE_OPTIONS='--max-old-space-size=2048' yarn --cwd #{ember_dir} run ember build -prod")
       STDERR.puts "Error running ember build"
       exit 1
     end