Revert "DEV: Update to Sprockets 4.0 (#16467)" (#16524)

This reverts commit 01107e418e.

We have seen some random occurrences of corrupted assets, and think it may be related to the sprockets 4 update. Reverting for investigation

Gemfile

@@ -31,7 +31,9 @@ end
 
 gem 'json'
 
-gem 'sprockets'
+# TODO: At the moment Discourse does not work with Sprockets 4, we would need to correct internals
+# This is a desired upgrade we should get to.
+gem 'sprockets', '3.7.2'
 
 # this will eventually be added to rails,
 # allows us to precompile all our templates in the unicorn master

Gemfile.lock

@@ -443,7 +443,7 @@ GEM
       simplecov_json_formatter (~> 0.1)
     simplecov-html (0.12.3)
     simplecov_json_formatter (0.1.4)
-    sprockets (4.0.3)
+    sprockets (3.7.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
     sprockets-rails (3.4.2)
@@ -602,7 +602,7 @@ DEPENDENCIES
   shoulda-matchers
   sidekiq
   simplecov
-  sprockets
+  sprockets (= 3.7.2)
   sprockets-rails
   sshkey
   stackprof

app/assets/config/manifest.js

@@ -1 +0,0 @@
-//= link_tree ../images

config/application.rb

@@ -142,12 +142,11 @@ module Discourse
     config.assets.skip_minification = []
 
     # explicitly precompile any images in plugins ( /assets/images ) path
-    Dir.glob("#{config.root}/plugins/*/assets/images/**/*").each do |filename|
-      config.assets.precompile << filename if !%w(.js .css).include?(File.extname(filename))
-    end
+    config.assets.precompile += [lambda do |filename, path|
+      path =~ /assets\/images/ && !%w(.js .css).include?(File.extname(filename))
+    end]
 
     config.assets.precompile += %w{
-      application.js
       vendor.js
       admin.js
       browser-detect.js
@@ -194,6 +193,25 @@ module Discourse
       end
     end
 
+    # out of the box sprockets 3 grabs loose files that are hanging in assets,
+    # the exclusion list does not include hbs so you double compile all this stuff
+    initializer :fix_sprockets_loose_file_searcher, after: :set_default_precompile do |app|
+      app.config.assets.precompile.delete(Sprockets::Railtie::LOOSE_APP_ASSETS)
+
+      # We don't want application from node_modules, only from the root
+      app.config.assets.precompile.delete(/(?:\/|\\|\A)application\.(css|js)$/)
+      app.config.assets.precompile += ['application.js']
+
+      start_path = ::Rails.root.join("app/assets").to_s
+      exclude = ['.es6', '.hbs', '.hbr', '.js', '.css', '.lock', '.json', '.log', '.html', '']
+      app.config.assets.precompile << lambda do |logical_path, filename|
+        filename.start_with?(start_path) &&
+        !filename.include?("/node_modules/") &&
+        !filename.include?("/dist/") &&
+        !exclude.include?(File.extname(logical_path))
+      end
+    end
+
     # Set Time.zone default to the specified zone and make Active Record auto-convert to this zone.
     # Run "rake -D time" for a list of tasks for finding time zone names. Default is UTC.
     config.time_zone = 'UTC'
@@ -272,11 +290,6 @@ module Discourse
     Sprockets.register_mime_type 'application/javascript', extensions: ['.js', '.es6', '.js.es6'], charset: :unicode
     Sprockets.register_postprocessor 'application/javascript', DiscourseJsProcessor
 
-    # This class doesn't exist in Sprockets 4, but ember-rails tries to 'autoload' it
-    # Define an empty class to prevent an error
-    class Sprockets::Engines
-    end
-
     require 'discourse_redis'
     require 'logster/redis_store'
     # Use redis for our cache

lib/freedom_patches/ember_sprockets_4.rb

@@ -1,12 +0,0 @@
-# frozen_string_literal: true
-
-# One of the initializers in `discourse-ember-rails/lib/ember_rails.rb` tries to set
-# the ember template compiler path based on a call to `Sprockets::Environment#resolve`
-# which started returning an array in Sprockets 4.
-# This doesn't seem to be needed - it was setting to the existing value, so we can just ignore it.
-Ember::Handlebars::Template.singleton_class.prepend(Module.new do
-  def setup_ember_template_compiler(path)
-    return if path.is_a? Array
-    super
-  end
-end)