Merge pull request #21794 from jeremy/sprockets/move-asset-manifest-from-toplevel-to-config-subdir

Eliminate overlapping `app/assets` load path

4 files changed, 229 insertions, 168 deletions

diff --git a/railties/test/application/asset_debugging_test.rb b/railties/test/application/asset_debugging_test.rb
index fef65adda2..8b83784ed6 100644
--- a/railties/test/application/asset_debugging_test.rb
+++ b/railties/test/application/asset_debugging_test.rb
@@ -7,7 +7,10 @@ module ApplicationTests
     include Rack::Test::Methods
 
     def setup
-      build_app(initializers: true)
+      # FIXME: shush Sass warning spam, not relevant to testing Railties
+      Kernel.silence_warnings do
+        build_app(initializers: true)
+      end
 
       app_file "app/assets/javascripts/application.js", "//= require_tree ."
       app_file "app/assets/javascripts/xmlhr.js", "function f1() { alert(); }"
@@ -33,12 +36,19 @@ module ApplicationTests
       teardown_app
     end
 
+    # FIXME: shush Sass warning spam, not relevant to testing Railties
+    def get(*)
+      Kernel.silence_warnings { super }
+    end
+
     test "assets are concatenated when debug is off and compile is off either if debug_assets param is provided" do
       # config.assets.debug and config.assets.compile are false for production environment
       ENV["RAILS_ENV"] = "production"
       output = Dir.chdir(app_path){ `bin/rake assets:precompile --trace 2>&1` }
       assert $?.success?, output
-      require "#{app_path}/config/environment"
+
+      # Load app env
+      app "production"
 
       class ::PostsController < ActionController::Base ; end
 
@@ -51,8 +61,8 @@ module ApplicationTests
     test "assets are served with sourcemaps when compile is true and debug_assets params is true" do
       add_to_env_config "production", "config.assets.compile = true"
 
-      ENV["RAILS_ENV"] = "production"
-      require "#{app_path}/config/environment"
+      # Load app env
+      app "production"
 
       class ::PostsController < ActionController::Base ; end
 
diff --git a/railties/test/application/assets_test.rb b/railties/test/application/assets_test.rb
index ddcd51f3fc..dca5cf2e5b 100644
--- a/railties/test/application/assets_test.rb
+++ b/railties/test/application/assets_test.rb
@@ -17,14 +17,23 @@ module ApplicationTests
     end
 
     def precompile!(env = nil)
-      quietly do
-        precompile_task = "bin/rake assets:precompile #{env} --trace 2>&1"
-        output = Dir.chdir(app_path) { %x[ #{precompile_task} ] }
-        assert $?.success?, output
-        output
+      with_env env.to_h do
+        quietly do
+          precompile_task = "bin/rake assets:precompile --trace 2>&1"
+          output = Dir.chdir(app_path) { %x[ #{precompile_task} ] }
+          assert $?.success?, output
+          output
+        end
       end
     end
 
+    def with_env(env)
+      env.each { |k, v| ENV[k.to_s] = v }
+      yield
+    ensure
+      env.each_key { |k| ENV.delete k.to_s }
+    end
+
     def clean_assets!
       quietly do
         assert Dir.chdir(app_path) { system('bin/rake assets:clobber') }
@@ -32,7 +41,8 @@ module ApplicationTests
     end
 
     def assert_file_exists(filename)
-      assert Dir[filename].first, "missing #{filename}"
+      globbed = Dir[filename]
+      assert globbed.one?, "Found #{globbed.size} files matching #{filename}. All files in the directory: #{Dir.entries(File.dirname(filename)).inspect}"
     end
 
     def assert_no_file_exists(filename)
@@ -51,7 +61,10 @@ module ApplicationTests
 
       add_to_env_config "development", "config.assets.digest = false"
 
-      require "#{app_path}/config/environment"
+      # FIXME: shush Sass warning spam, not relevant to testing Railties
+      Kernel.silence_warnings do
+        require "#{app_path}/config/environment"
+      end
 
       get "/assets/demo.js"
       assert_equal 'a = "/assets/rails.png";', last_response.body.strip
@@ -62,8 +75,8 @@ module ApplicationTests
       add_to_env_config "production", "config.assets.compile = true"
       add_to_env_config "production", "config.assets.precompile = []"
 
-      ENV["RAILS_ENV"] = "production"
-      require "#{app_path}/config/environment"
+      # Load app env
+      app "production"
 
       assert !defined?(Uglifier)
       get "/assets/demo.js"
@@ -72,11 +85,10 @@ module ApplicationTests
     end
 
     test "precompile creates the file, gives it the original asset's content and run in production as default" do
-      app_file "app/assets/manifest.js", "//= link_tree ./javascripts"
+      app_file "app/assets/config/manifest.js", "//= link_tree ../javascripts"
       app_file "app/assets/javascripts/application.js", "alert();"
       app_file "app/assets/javascripts/foo/application.js", "alert();"
 
-      ENV["RAILS_ENV"] = nil
       precompile!
 
       files = Dir["#{app_path}/public/assets/application-*.js"]
@@ -88,7 +100,7 @@ module ApplicationTests
     end
 
     def test_precompile_does_not_hit_the_database
-      app_file "app/assets/manifest.js", "//= link_tree ./javascripts"
+      app_file "app/assets/config/manifest.js", "//= link_tree ../javascripts"
       app_file "app/assets/javascripts/application.js", "alert();"
       app_file "app/assets/javascripts/foo/application.js", "alert();"
       app_file "app/controllers/users_controller.rb", <<-eoruby
@@ -98,10 +110,9 @@ module ApplicationTests
         class User < ActiveRecord::Base; raise 'should not be reached'; end
       eoruby
 
-      ENV['RAILS_ENV']  = 'production'
-      ENV['DATABASE_URL'] = 'postgresql://baduser:badpass@127.0.0.1/dbname'
-
-      precompile!
+      precompile! \
+        RAILS_ENV: 'production',
+        DATABASE_URL: 'postgresql://baduser:badpass@127.0.0.1/dbname'
 
       files = Dir["#{app_path}/public/assets/application-*.js"]
       files << Dir["#{app_path}/public/assets/foo/application-*.js"].first
@@ -109,9 +120,6 @@ module ApplicationTests
         assert_not_nil file, "Expected application.js asset to be generated, but none found"
         assert_equal "alert();".strip, File.read(file).strip
       end
-    ensure
-      ENV.delete 'RAILS_ENV'
-      ENV.delete 'DATABASE_URL'
     end
 
     test "precompile application.js and application.css and all other non JS/CSS files" do
@@ -171,10 +179,9 @@ module ApplicationTests
 
     test 'precompile use assets defined in app env config' do
       add_to_env_config 'production', 'config.assets.precompile = [ "something.js" ]'
-
       app_file 'app/assets/javascripts/something.js.erb', 'alert();'
 
-      precompile! 'RAILS_ENV=production'
+      precompile! RAILS_ENV: 'production'
 
       assert_file_exists("#{app_path}/public/assets/something-*.js")
     end
@@ -183,15 +190,17 @@ module ApplicationTests
       add_to_config 'config.assets.precompile = [ "something_manifest.js" ]'
       add_to_env_config 'production', 'config.assets.precompile += [ "another_manifest.js" ]'
 
-      app_file 'app/assets/something_manifest.js', '//= link ./javascripts/something.js'
-      app_file 'app/assets/another_manifest.js', '//= link ./javascripts/another.js'
+      app_file 'app/assets/config/something_manifest.js', '//= link something.js'
+      app_file 'app/assets/config/another_manifest.js', '//= link another.js'
 
       app_file 'app/assets/javascripts/something.js.erb', 'alert();'
       app_file 'app/assets/javascripts/another.js.erb', 'alert();'
 
-      precompile! 'RAILS_ENV=production'
+      precompile! RAILS_ENV: 'production'
 
+      assert_file_exists("#{app_path}/public/assets/something_manifest-*.js")
       assert_file_exists("#{app_path}/public/assets/something-*.js")
+      assert_file_exists("#{app_path}/public/assets/another_manifest-*.js")
       assert_file_exists("#{app_path}/public/assets/another-*.js")
     end
 
@@ -199,8 +208,8 @@ module ApplicationTests
       add_to_config "config.action_controller.perform_caching = false"
       add_to_env_config "production", "config.assets.compile = true"
 
-      ENV["RAILS_ENV"] = "production"
-      require "#{app_path}/config/environment"
+      # Load app env
+      app "production"
 
       assert_equal Sprockets::CachedEnvironment, Rails.application.assets.class
     end
@@ -211,8 +220,8 @@ module ApplicationTests
       app_file "app/assets/javascripts/application.js", "alert();"
 
       precompile!
-      manifest = Dir["#{app_path}/public/assets/.sprockets-manifest-*.json"].first
 
+      manifest = Dir["#{app_path}/public/assets/.sprockets-manifest-*.json"].first
       assets = ActiveSupport::JSON.decode(File.read(manifest))
       assert_match(/application-([0-z]+)\.js/, assets["assets"]["application.js"])
       assert_match(/application-([0-z]+)\.css/, assets["assets"]["application.css"])
@@ -233,14 +242,14 @@ module ApplicationTests
       app_file "app/assets/javascripts/application.js", "alert();"
       add_to_env_config "production", "config.serve_static_files = true"
 
-      ENV["RAILS_ENV"] = "production"
-      precompile!
+      precompile! RAILS_ENV: 'production'
 
       manifest = Dir["#{app_path}/public/assets/.sprockets-manifest-*.json"].first
       assets = ActiveSupport::JSON.decode(File.read(manifest))
       asset_path = assets["assets"]["application.js"]
 
-      require "#{app_path}/config/environment"
+      # Load app env
+      app "production"
 
       # Checking if Uglifier is defined we can know if Sprockets was reached or not
       assert !defined?(Uglifier)
@@ -249,12 +258,11 @@ module ApplicationTests
       assert !defined?(Uglifier)
     end
 
-    test "precompile properly refers files referenced with asset_path and runs in the provided RAILS_ENV" do
+    test "precompile properly refers files referenced with asset_path" do
       app_file "app/assets/images/rails.png", "notactuallyapng"
       app_file "app/assets/stylesheets/application.css.erb", "p { background-image: url(<%= asset_path('rails.png') %>) }"
-      add_to_env_config "test", "config.assets.digest = true"
 
-      precompile!('RAILS_ENV=test')
+      precompile!
 
       file = Dir["#{app_path}/public/assets/application-*.css"].first
       assert_match(/\/assets\/rails-([0-z]+)\.png/, File.read(file))
@@ -265,8 +273,7 @@ module ApplicationTests
 
       app_file "app/assets/stylesheets/application.css.erb", "p { background-image: url(<%= asset_path('rails.png') %>) }"
 
-      ENV["RAILS_ENV"] = "production"
-      precompile!
+      precompile! RAILS_ENV: 'production'
 
       manifest = Dir["#{app_path}/public/assets/.sprockets-manifest-*.json"].first
       assets = ActiveSupport::JSON.decode(File.read(manifest))
@@ -275,8 +282,8 @@ module ApplicationTests
       app_file "app/assets/images/rails.png", "p { url: change }"
 
       precompile!
-      assets = ActiveSupport::JSON.decode(File.read(manifest))
 
+      assets = ActiveSupport::JSON.decode(File.read(manifest))
       assert_not_equal asset_path, assets["assets"]["application.css"]
     end
 
@@ -284,8 +291,7 @@ module ApplicationTests
       app_file "app/assets/images/rails.png", "notactuallyapng"
       app_file "app/assets/stylesheets/application.css.erb", "p { background-image: url(<%= asset_path('rails.png') %>) }"
 
-      ENV["RAILS_ENV"] = "production"
-      precompile!
+      precompile! RAILS_ENV: 'production'
 
       file = Dir["#{app_path}/public/assets/application-*.css"].first
       assert_match(/\/assets\/rails-([0-z]+)\.png/, File.read(file))
@@ -294,7 +300,7 @@ module ApplicationTests
     test "precompile should handle utf8 filenames" do
       filename = "レイルズ.png"
       app_file "app/assets/images/#{filename}", "not an image really"
-      app_file "app/assets/manifest.js", "//= link_tree ./images"
+      app_file "app/assets/config/manifest.js", "//= link_tree ../images"
       add_to_config "config.assets.precompile = %w(manifest.js)"
 
       precompile!
@@ -303,7 +309,8 @@ module ApplicationTests
       assets = ActiveSupport::JSON.decode(File.read(manifest))
       assert asset_path = assets["assets"].find { |(k, _)| k && k =~ /.png/ }[1]
 
-      require "#{app_path}/config/environment"
+      # Load app env
+      app "development"
 
       get "/assets/#{URI.parser.escape(asset_path)}"
       assert_match "not an image really", last_response.body
@@ -326,8 +333,8 @@ module ApplicationTests
       app_file "app/assets/javascripts/demo.js.erb", "<%= :alert %>();"
       add_to_config "config.assets.compile = false"
 
-      ENV["RAILS_ENV"] = "production"
-      require "#{app_path}/config/environment"
+      # Load app env
+      app "production"
 
       get "/assets/demo.js"
       assert_equal 404, last_response.status
@@ -344,7 +351,8 @@ module ApplicationTests
 
       add_to_env_config "development", "config.assets.digest = false"
 
-      require "#{app_path}/config/environment"
+      # Load app env
+      app "development"
 
       class ::OmgController < ActionController::Base
         def index
@@ -370,7 +378,8 @@ module ApplicationTests
 
       add_to_env_config "development", "config.assets.digest = false"
 
-      require "#{app_path}/config/environment"
+      # Load app env
+      app "development"
 
       get "/assets/demo.js"
       assert_match "alert();", last_response.body
@@ -381,10 +390,10 @@ module ApplicationTests
       app_with_assets_in_view
 
       # config.assets.debug and config.assets.compile are false for production environment
-      ENV["RAILS_ENV"] = "production"
-      precompile!
+      precompile! RAILS_ENV: 'production'
 
-      require "#{app_path}/config/environment"
+      # Load app env
+      app "production"
 
       class ::PostsController < ActionController::Base ; end
 
@@ -400,6 +409,7 @@ module ApplicationTests
       app_file "app/assets/javascripts/xmlhr.js.erb", "<%= Post.name %>"
 
       precompile!
+
       assert_equal "Post\n;\n", File.read(Dir["#{app_path}/public/assets/application-*.js"].first)
     end
 
@@ -441,7 +451,10 @@ module ApplicationTests
       app_with_assets_in_view
       add_to_config "config.asset_host = 'example.com'"
       add_to_env_config "development", "config.assets.digest = false"
-      require "#{app_path}/config/environment"
+
+      # Load app env
+      app "development"
+
       class ::PostsController < ActionController::Base; end
 
       get '/posts', {}, {'HTTPS'=>'off'}
@@ -456,6 +469,7 @@ module ApplicationTests
       add_to_config "config.assets.precompile = %w{rails.png image_loader.js}"
       add_to_config "config.asset_host = 'example.com'"
       add_to_env_config "development", "config.assets.digest = false"
+
       precompile!
 
       assert_match "src='//example.com/assets/rails.png'", File.read(Dir["#{app_path}/public/assets/image_loader-*.js"].first)
@@ -467,6 +481,7 @@ module ApplicationTests
       app_file "app/assets/javascripts/app.js.erb", "var src='<%= image_path('rails.png') %>';"
       add_to_config "config.assets.precompile = %w{rails.png app.js}"
       add_to_env_config "development", "config.assets.digest = false"
+
       precompile!
 
       assert_match "src='/sub/uri/assets/rails.png'", File.read(Dir["#{app_path}/public/assets/app-*.js"].first)
diff --git a/railties/test/application/configuration_test.rb b/railties/test/application/configuration_test.rb
index 464fc1688c..2f407cd851 100644
--- a/railties/test/application/configuration_test.rb
+++ b/railties/test/application/configuration_test.rb
@@ -34,8 +34,19 @@ module ApplicationTests
       FileUtils.cp_r(app_path, new_app)
     end
 
-    def app
-      @app ||= Rails.application
+    def app(env = 'development')
+      @app ||= begin
+        ENV['RAILS_ENV'] = env
+
+        # FIXME: shush Sass warning spam, not relevant to testing Railties
+        Kernel.silence_warnings do
+          require "#{app_path}/config/environment"
+        end
+
+        Rails.application
+      ensure
+        ENV.delete 'RAILS_ENV'
+      end
     end
 
     def setup
@@ -78,7 +89,9 @@ module ApplicationTests
         require 'my_logger'
         config.logger = MyLogger.new STDOUT
       RUBY
-      require "#{app_path}/config/environment"
+
+      app 'development'
+
       assert_equal 'MyLogger', Rails.application.config.logger.class.name
     end
 
@@ -97,7 +110,7 @@ module ApplicationTests
         end
       RUBY
 
-      require "#{app_path}/config/environment"
+      app 'development'
 
       ActiveRecord::Migrator.migrations_paths = ["#{app_path}/db/migrate"]
 
@@ -128,29 +141,29 @@ module ApplicationTests
     test "Rails.application is nil until app is initialized" do
       require 'rails'
       assert_nil Rails.application
-      require "#{app_path}/config/environment"
+      app 'development'
       assert_equal AppTemplate::Application.instance, Rails.application
     end
 
     test "Rails.application responds to all instance methods" do
-      require "#{app_path}/config/environment"
+      app 'development'
       assert_respond_to Rails.application, :routes_reloader
       assert_equal Rails.application.routes_reloader, AppTemplate::Application.routes_reloader
     end
 
     test "Rails::Application responds to paths" do
-      require "#{app_path}/config/environment"
+      app 'development'
       assert_respond_to AppTemplate::Application, :paths
       assert_equal ["#{app_path}/app/views"], AppTemplate::Application.paths["app/views"].expanded
     end
 
     test "the application root is set correctly" do
-      require "#{app_path}/config/environment"
+      app 'development'
       assert_equal Pathname.new(app_path), Rails.application.root
     end
 
     test "the application root can be seen from the application singleton" do
-      require "#{app_path}/config/environment"
+      app 'development'
       assert_equal Pathname.new(app_path), AppTemplate::Application.root
     end
 
@@ -162,7 +175,8 @@ module ApplicationTests
 
       use_frameworks []
 
-      require "#{app_path}/config/environment"
+      app 'development'
+
       assert_equal Pathname.new(new_app), Rails.application.root
     end
 
@@ -172,7 +186,7 @@ module ApplicationTests
       use_frameworks []
 
       Dir.chdir("#{app_path}") do
-        require "#{app_path}/config/environment"
+        app 'development'
         assert_equal Pathname.new("#{app_path}"), Rails.application.root
       end
     end
@@ -181,7 +195,9 @@ module ApplicationTests
       add_to_config <<-RUBY
         config.root = "#{app_path}"
       RUBY
-      require "#{app_path}/config/environment"
+
+      app 'development'
+
       assert_instance_of Pathname, Rails.root
     end
 
@@ -189,7 +205,9 @@ module ApplicationTests
       add_to_config <<-RUBY
         config.paths["public"] = "somewhere"
       RUBY
-      require "#{app_path}/config/environment"
+
+      app 'development'
+
       assert_instance_of Pathname, Rails.public_path
     end
 
@@ -199,12 +217,13 @@ module ApplicationTests
         config.cache_classes = true
       RUBY
 
-      require "#{app_path}/config/application"
-      assert Rails.application.initialize!
+      app 'development'
+
+      assert_equal :require, ActiveSupport::Dependencies.mechanism
     end
 
     test "application is always added to eager_load namespaces" do
-      require "#{app_path}/config/application"
+      app 'development'
       assert_includes Rails.application.config.eager_load_namespaces, AppTemplate::Application
     end
 
@@ -218,7 +237,7 @@ module ApplicationTests
       use_frameworks []
 
       assert_nothing_raised do
-        require "#{app_path}/config/application"
+        app 'development'
       end
     end
 
@@ -230,7 +249,7 @@ module ApplicationTests
       RUBY
 
       assert_nothing_raised do
-        require "#{app_path}/config/application"
+        app 'development'
       end
     end
 
@@ -239,7 +258,7 @@ module ApplicationTests
         Rails.application.config.filter_parameters += [ :password, :foo, 'bar' ]
       RUBY
 
-      require "#{app_path}/config/environment"
+      app 'development'
 
       assert_equal [:password, :foo, 'bar'], Rails.application.env_config['action_dispatch.parameter_filter']
     end
@@ -255,7 +274,7 @@ module ApplicationTests
 
       assert !$prepared
 
-      require "#{app_path}/config/environment"
+      app 'development'
 
       get "/"
       assert $prepared
@@ -267,7 +286,7 @@ module ApplicationTests
     end
 
     test "skipping config.encoding still results in 'utf-8' as the default" do
-      require "#{app_path}/config/application"
+      app 'development'
       assert_utf8
     end
 
@@ -276,7 +295,7 @@ module ApplicationTests
         config.encoding = "utf-8"
       RUBY
 
-      require "#{app_path}/config/application"
+      app 'development'
       assert_utf8
     end
 
@@ -285,7 +304,7 @@ module ApplicationTests
         config.paths["public"] = "somewhere"
       RUBY
 
-      require "#{app_path}/config/application"
+      app 'development'
       assert_equal Pathname.new(app_path).join("somewhere"), Rails.public_path
     end
 
@@ -293,7 +312,7 @@ module ApplicationTests
       restore_default_config
 
       with_rails_env "production" do
-        require "#{app_path}/config/environment"
+        app 'production'
         assert_not app.config.serve_static_files
       end
     end
@@ -303,7 +322,7 @@ module ApplicationTests
 
       with_rails_env "production" do
         switch_env "RAILS_SERVE_STATIC_FILES", "1" do
-          require "#{app_path}/config/environment"
+          app 'production'
           assert app.config.serve_static_files
         end
       end
@@ -314,7 +333,7 @@ module ApplicationTests
 
       with_rails_env "production" do
         switch_env "RAILS_SERVE_STATIC_FILES", " " do
-          require "#{app_path}/config/environment"
+          app 'production'
           assert_not app.config.serve_static_files
         end
       end
@@ -363,8 +382,8 @@ module ApplicationTests
         development:
           secret_key_base:
       YAML
-      require "#{app_path}/config/environment"
 
+      app 'development'
 
       assert_equal app.env_config['action_dispatch.key_generator'], Rails.application.key_generator
       assert_equal app.env_config['action_dispatch.key_generator'].class, ActiveSupport::LegacyKeyGenerator
@@ -380,7 +399,8 @@ module ApplicationTests
         development:
           secret_key_base:
       YAML
-      require "#{app_path}/config/environment"
+
+      app 'development'
 
       assert_deprecated(/You didn't set `secret_key_base`./) do
         app.env_config
@@ -395,7 +415,8 @@ module ApplicationTests
         development:
           secret_token: 3b7cd727ee24e8444053437c36cc66c3
       YAML
-      require "#{app_path}/config/environment"
+
+      app 'development'
 
       assert_equal '3b7cd727ee24e8444053437c36cc66c3', app.secrets.secret_token
     end
@@ -426,7 +447,7 @@ module ApplicationTests
           secret_key_base: 3b7cd727ee24e8444053437c36cc66c3
       YAML
 
-      require "#{app_path}/config/environment"
+      app 'development'
       assert_equal '3b7cd727ee24e8444053437c36cc66c3', app.secrets.secret_key_base
     end
 
@@ -436,7 +457,7 @@ module ApplicationTests
         Rails.application.config.secret_key_base = "3b7cd727ee24e8444053437c36cc66c3"
       RUBY
 
-      require "#{app_path}/config/environment"
+      app 'development'
       assert_equal '3b7cd727ee24e8444053437c36cc66c3', app.secrets.secret_key_base
     end
 
@@ -449,7 +470,8 @@ module ApplicationTests
           secret_key_base:
           secret_token:
       YAML
-      require "#{app_path}/config/environment"
+
+      app 'development'
 
       assert_equal 'b3c631c314c0bbca50c1b2843150fe33', app.secrets.secret_token
       assert_equal 'b3c631c314c0bbca50c1b2843150fe33', app.config.secret_token
@@ -463,7 +485,8 @@ module ApplicationTests
           aws_secret_access_key: myamazonsecretaccesskey
       YAML
 
-      require "#{app_path}/config/environment"
+      app 'development'
+
       assert_equal 'myamazonaccesskeyid', app.secrets.aws_access_key_id
       assert_equal 'myamazonsecretaccesskey', app.secrets.aws_secret_access_key
     end
@@ -471,7 +494,8 @@ module ApplicationTests
     test "blank config/secrets.yml does not crash the loading process" do
       app_file 'config/secrets.yml', <<-YAML
       YAML
-      require "#{app_path}/config/environment"
+
+      app 'development'
 
       assert_nil app.secrets.not_defined
     end
@@ -484,7 +508,8 @@ module ApplicationTests
         development:
           secret_key_base:
       YAML
-      require "#{app_path}/config/environment"
+
+      app 'development'
 
       assert_equal "iaminallyoursecretkeybase", app.secrets.secret_key_base
     end
@@ -497,7 +522,8 @@ module ApplicationTests
         development:
           secret_key_base:
       YAML
-      require "#{app_path}/config/environment"
+
+      app 'development'
 
       assert_equal 'b3c631c314c0bbca50c1b2843150fe33', app.config.secret_token
       assert_equal nil, app.secrets.secret_key_base
@@ -512,7 +538,8 @@ module ApplicationTests
         development:
           secret_key_base:
       YAML
-      require "#{app_path}/config/environment"
+
+      app 'development'
 
       assert_equal '', app.config.secret_token
       assert_equal nil, app.secrets.secret_key_base
@@ -535,7 +562,6 @@ module ApplicationTests
     end
 
     test "default form builder specified as a string" do
-
       app_file 'config/initializers/form_builder.rb', <<-RUBY
       class CustomFormBuilder < ActionView::Helpers::FormBuilder
         def text_field(attribute, *args)
@@ -567,7 +593,7 @@ module ApplicationTests
         end
       RUBY
 
-      require "#{app_path}/config/environment"
+      app 'development'
 
       get "/posts"
       assert_match(/label/, last_response.body)
@@ -606,9 +632,9 @@ module ApplicationTests
         end
       RUBY
 
-      require "#{app_path}/config/environment"
+      app 'development'
 
-      params = {authenticity_token: token}
+      params = { authenticity_token: token }
 
       get "/posts/1"
       assert_match(/patch/, last_response.body)
@@ -659,9 +685,9 @@ module ApplicationTests
         config.action_mailer.interceptors = MyMailInterceptor
       RUBY
 
-      require "#{app_path}/config/environment"
-      require "mail"
+      app 'development'
 
+      require "mail"
       _ = ActionMailer::Base
 
       assert_equal [::MyMailInterceptor], ::Mail.send(:class_variable_get, "@@delivery_interceptors")
@@ -672,9 +698,9 @@ module ApplicationTests
         config.action_mailer.interceptors = [MyMailInterceptor, "MyOtherMailInterceptor"]
       RUBY
 
-      require "#{app_path}/config/environment"
-      require "mail"
+      app 'development'
 
+      require "mail"
       _ = ActionMailer::Base
 
       assert_equal [::MyMailInterceptor, ::MyOtherMailInterceptor], ::Mail.send(:class_variable_get, "@@delivery_interceptors")
@@ -685,9 +711,9 @@ module ApplicationTests
         config.action_mailer.preview_interceptors = MyPreviewMailInterceptor
       RUBY
 
-      require "#{app_path}/config/environment"
-      require "mail"
+      app 'development'
 
+      require "mail"
       _ = ActionMailer::Base
 
       assert_equal [ActionMailer::InlinePreviewInterceptor, ::MyPreviewMailInterceptor], ActionMailer::Base.preview_interceptors
@@ -698,9 +724,9 @@ module ApplicationTests
         config.action_mailer.preview_interceptors = [MyPreviewMailInterceptor, "MyOtherPreviewMailInterceptor"]
       RUBY
 
-      require "#{app_path}/config/environment"
-      require "mail"
+      app 'development'
 
+      require "mail"
       _ = ActionMailer::Base
 
       assert_equal [ActionMailer::InlinePreviewInterceptor, MyPreviewMailInterceptor, MyOtherPreviewMailInterceptor], ActionMailer::Base.preview_interceptors
@@ -711,9 +737,9 @@ module ApplicationTests
         ActionMailer::Base.preview_interceptors.delete(ActionMailer::InlinePreviewInterceptor)
       RUBY
 
-      require "#{app_path}/config/environment"
-      require "mail"
+      app 'development'
 
+      require "mail"
       _ = ActionMailer::Base
 
       assert_equal [], ActionMailer::Base.preview_interceptors
@@ -724,9 +750,9 @@ module ApplicationTests
         config.action_mailer.observers = MyMailObserver
       RUBY
 
-      require "#{app_path}/config/environment"
-      require "mail"
+      app 'development'
 
+      require "mail"
       _ = ActionMailer::Base
 
       assert_equal [::MyMailObserver], ::Mail.send(:class_variable_get, "@@delivery_notification_observers")
@@ -737,9 +763,9 @@ module ApplicationTests
         config.action_mailer.observers = [MyMailObserver, "MyOtherMailObserver"]
       RUBY
 
-      require "#{app_path}/config/environment"
-      require "mail"
+      app 'development'
 
+      require "mail"
       _ = ActionMailer::Base
 
       assert_equal [::MyMailObserver, ::MyOtherMailObserver], ::Mail.send(:class_variable_get, "@@delivery_notification_observers")
@@ -750,9 +776,9 @@ module ApplicationTests
         config.action_mailer.deliver_later_queue_name = 'test_default'
       RUBY
 
-      require "#{app_path}/config/environment"
-      require "mail"
+      app 'development'
 
+      require "mail"
       _ = ActionMailer::Base
 
       assert_equal 'test_default', ActionMailer::Base.send(:class_variable_get, "@@deliver_later_queue_name")
@@ -764,7 +790,7 @@ module ApplicationTests
         config.time_zone = "Wellington"
       RUBY
 
-      require "#{app_path}/config/environment"
+      app 'development'
 
       assert_equal "Wellington", Rails.application.config.time_zone
     end
@@ -776,7 +802,7 @@ module ApplicationTests
       RUBY
 
       assert_raise(ArgumentError) do
-        require "#{app_path}/config/environment"
+        app 'development'
       end
     end
 
@@ -786,7 +812,7 @@ module ApplicationTests
         config.beginning_of_week = :wednesday
       RUBY
 
-      require "#{app_path}/config/environment"
+      app 'development'
 
       assert_equal :wednesday, Rails.application.config.beginning_of_week
     end
@@ -798,13 +824,14 @@ module ApplicationTests
       RUBY
 
       assert_raise(ArgumentError) do
-        require "#{app_path}/config/environment"
+        app 'development'
       end
     end
 
     test "config.action_view.cache_template_loading with cache_classes default" do
       add_to_config "config.cache_classes = true"
-      require "#{app_path}/config/environment"
+
+      app 'development'
       require 'action_view/base'
 
       assert_equal true, ActionView::Resolver.caching?
@@ -812,7 +839,8 @@ module ApplicationTests
 
     test "config.action_view.cache_template_loading without cache_classes default" do
       add_to_config "config.cache_classes = false"
-      require "#{app_path}/config/environment"
+
+      app 'development'
       require 'action_view/base'
 
       assert_equal false, ActionView::Resolver.caching?
@@ -823,7 +851,8 @@ module ApplicationTests
         config.cache_classes = true
         config.action_view.cache_template_loading = false
       RUBY
-      require "#{app_path}/config/environment"
+
+      app 'development'
       require 'action_view/base'
 
       assert_equal false, ActionView::Resolver.caching?
@@ -834,7 +863,8 @@ module ApplicationTests
         config.cache_classes = false
         config.action_view.cache_template_loading = true
       RUBY
-      require "#{app_path}/config/environment"
+
+      app 'development'
       require 'action_view/base'
 
       assert_equal true, ActionView::Resolver.caching?
@@ -849,7 +879,7 @@ module ApplicationTests
       require 'action_view/railtie'
       require 'action_view/base'
 
-      require "#{app_path}/config/environment"
+      app 'development'
 
       assert_equal false, ActionView::Resolver.caching?
     end
@@ -902,7 +932,7 @@ module ApplicationTests
         end
       RUBY
 
-      require "#{app_path}/config/environment"
+      app 'development'
 
       post "/posts.json", '{ "title": "foo", "name": "bar" }', "CONTENT_TYPE" => "application/json"
       assert_equal '{"title"=>"foo"}', last_response.body
@@ -924,7 +954,7 @@ module ApplicationTests
         config.action_controller.permit_all_parameters = true
       RUBY
 
-      require "#{app_path}/config/environment"
+      app 'development'
 
       post "/posts", {post: {"title" =>"zomg"}}
       assert_equal 'permitted', last_response.body
@@ -946,7 +976,7 @@ module ApplicationTests
         config.action_controller.action_on_unpermitted_parameters = :raise
       RUBY
 
-      require "#{app_path}/config/environment"
+      app 'development'
 
       assert_equal :raise, ActionController::Parameters.action_on_unpermitted_parameters
 
@@ -955,7 +985,7 @@ module ApplicationTests
     end
 
     test "config.action_controller.always_permitted_parameters are: controller, action by default" do
-      require "#{app_path}/config/environment"
+      app 'development'
       assert_equal %w(controller action), ActionController::Parameters.always_permitted_parameters
     end
 
@@ -963,7 +993,9 @@ module ApplicationTests
       add_to_config <<-RUBY
         config.action_controller.always_permitted_parameters = %w( controller action format )
       RUBY
-      require "#{app_path}/config/environment"
+
+      app 'development'
+
       assert_equal %w( controller action format ), ActionController::Parameters.always_permitted_parameters
     end
 
@@ -984,7 +1016,7 @@ module ApplicationTests
         config.action_controller.action_on_unpermitted_parameters = :raise
       RUBY
 
-      require "#{app_path}/config/environment"
+      app 'development'
 
       assert_equal :raise, ActionController::Parameters.action_on_unpermitted_parameters
 
@@ -993,25 +1025,19 @@ module ApplicationTests
     end
 
     test "config.action_controller.action_on_unpermitted_parameters is :log by default on development" do
-      ENV["RAILS_ENV"] = "development"
-
-      require "#{app_path}/config/environment"
+      app 'development'
 
       assert_equal :log, ActionController::Parameters.action_on_unpermitted_parameters
     end
 
     test "config.action_controller.action_on_unpermitted_parameters is :log by default on test" do
-      ENV["RAILS_ENV"] = "test"
-
-      require "#{app_path}/config/environment"
+      app 'test'
 
       assert_equal :log, ActionController::Parameters.action_on_unpermitted_parameters
     end
 
     test "config.action_controller.action_on_unpermitted_parameters is false by default on production" do
-      ENV["RAILS_ENV"] = "production"
-
-      require "#{app_path}/config/environment"
+      app 'production'
 
       assert_equal false, ActionController::Parameters.action_on_unpermitted_parameters
     end
@@ -1089,17 +1115,14 @@ module ApplicationTests
 
     test "config.active_record.dump_schema_after_migration is false on production" do
       build_app
-      ENV["RAILS_ENV"] = "production"
 
-      require "#{app_path}/config/environment"
+      app 'production'
 
       assert_not ActiveRecord::Base.dump_schema_after_migration
     end
 
     test "config.active_record.dump_schema_after_migration is true by default on development" do
-      ENV["RAILS_ENV"] = "development"
-
-      require "#{app_path}/config/environment"
+      app 'development'
 
       assert ActiveRecord::Base.dump_schema_after_migration
     end
@@ -1125,7 +1148,7 @@ module ApplicationTests
         end
       RUBY
 
-      require "#{app_path}/config/environment"
+      app 'development'
       assert_not Rails.configuration.ran_block
 
       require 'rake'
@@ -1147,7 +1170,7 @@ module ApplicationTests
         end
       RUBY
 
-      require "#{app_path}/config/environment"
+      app 'development'
       assert_not Rails.configuration.ran_block
 
       Rails.application.load_generators
@@ -1165,7 +1188,7 @@ module ApplicationTests
         end
       RUBY
 
-      require "#{app_path}/config/environment"
+      app 'development'
       assert_not Rails.configuration.ran_block
 
       Rails.application.load_console
@@ -1183,7 +1206,7 @@ module ApplicationTests
         end
       RUBY
 
-      require "#{app_path}/config/environment"
+      app 'development'
       assert_not Rails.configuration.ran_block
 
       Rails.application.load_runner
@@ -1199,14 +1222,14 @@ module ApplicationTests
         end
       RUBY
 
-      require "#{app_path}/config/environment"
+      app 'development'
 
       assert_kind_of Hash, Rails.application.config.database_configuration
     end
 
     test 'raises with proper error message if no database configuration found' do
       FileUtils.rm("#{app_path}/config/database.yml")
-      require "#{app_path}/config/environment"
+      app 'development'
       err = assert_raises RuntimeError do
         Rails.application.config.database_configuration
       end
@@ -1214,25 +1237,23 @@ module ApplicationTests
     end
 
     test 'config.action_mailer.show_previews defaults to true in development' do
-      Rails.env = "development"
-      require "#{app_path}/config/environment"
+      app 'development'
 
       assert Rails.application.config.action_mailer.show_previews
     end
 
     test 'config.action_mailer.show_previews defaults to false in production' do
-      Rails.env = "production"
-      require "#{app_path}/config/environment"
+      app 'production'
 
       assert_equal false, Rails.application.config.action_mailer.show_previews
     end
 
     test 'config.action_mailer.show_previews can be set in the configuration file' do
-      Rails.env = "production"
       add_to_config <<-RUBY
         config.action_mailer.show_previews = true
       RUBY
-      require "#{app_path}/config/environment"
+
+      app 'production'
 
       assert_equal true, Rails.application.config.action_mailer.show_previews
     end
@@ -1247,7 +1268,7 @@ module ApplicationTests
         config.my_custom_config = config_for('custom')
       RUBY
 
-      require "#{app_path}/config/environment"
+      app 'development'
 
       assert_equal 'custom key', Rails.application.config.my_custom_config['key']
     end
@@ -1258,7 +1279,7 @@ module ApplicationTests
       RUBY
 
       exception = assert_raises(RuntimeError) do
-        require "#{app_path}/config/environment"
+        app 'development'
       end
 
       assert_equal "Could not load configuration. No such file - #{app_path}/config/custom.yml", exception.message
@@ -1273,7 +1294,8 @@ module ApplicationTests
       add_to_config <<-RUBY
         config.my_custom_config = config_for('custom')
       RUBY
-      require "#{app_path}/config/environment"
+
+      app 'development'
 
       assert_equal({}, Rails.application.config.my_custom_config)
     end
@@ -1285,7 +1307,8 @@ module ApplicationTests
       add_to_config <<-RUBY
         config.my_custom_config = config_for('custom')
       RUBY
-      require "#{app_path}/config/environment"
+
+      app 'development'
 
       assert_equal({}, Rails.application.config.my_custom_config)
     end
@@ -1299,7 +1322,8 @@ module ApplicationTests
       add_to_config <<-RUBY
         config.my_custom_config = config_for('custom')
       RUBY
-      require "#{app_path}/config/environment"
+
+      app 'development'
 
       assert_equal 'custom key', Rails.application.config.my_custom_config['key']
     end
@@ -1315,7 +1339,7 @@ module ApplicationTests
       RUBY
 
       exception = assert_raises(RuntimeError) do
-        require "#{app_path}/config/environment"
+        app 'development'
       end
 
       assert_match 'YAML syntax error occurred while parsing', exception.message
diff --git a/railties/test/isolation/abstract_unit.rb b/railties/test/isolation/abstract_unit.rb
index 41d36680e0..73b0c417cb 100644
--- a/railties/test/isolation/abstract_unit.rb
+++ b/railties/test/isolation/abstract_unit.rb
@@ -51,7 +51,12 @@ module TestHelpers
       old_env = ENV["RAILS_ENV"]
       @app ||= begin
         ENV["RAILS_ENV"] = env
-        require "#{app_path}/config/environment"
+
+        # FIXME: shush Sass warning spam, not relevant to testing Railties
+        Kernel.silence_warnings do
+          require "#{app_path}/config/environment"
+        end
+
         Rails.application
       end
     ensure
@@ -161,18 +166,18 @@ module TestHelpers
       require "action_view/railtie"
       require 'action_dispatch/middleware/flash'
 
-      app = Class.new(Rails::Application)
-      app.config.eager_load = false
-      app.secrets.secret_key_base = "3b7cd727ee24e8444053437c36cc66c4"
-      app.config.session_store :cookie_store, key: "_myapp_session"
-      app.config.active_support.deprecation = :log
-      app.config.active_support.test_order = :random
-      app.config.log_level = :info
+      @app = Class.new(Rails::Application)
+      @app.config.eager_load = false
+      @app.secrets.secret_key_base = "3b7cd727ee24e8444053437c36cc66c4"
+      @app.config.session_store :cookie_store, key: "_myapp_session"
+      @app.config.active_support.deprecation = :log
+      @app.config.active_support.test_order = :random
+      @app.config.log_level = :info
 
-      yield app if block_given?
-      app.initialize!
+      yield @app if block_given?
+      @app.initialize!
 
-      app.routes.draw do
+      @app.routes.draw do
         get "/" => "omg#index"
       end
 
@@ -297,7 +302,10 @@ module TestHelpers
     end
 
     def boot_rails
-      require File.expand_path('../../../../load_paths', __FILE__)
+      # FIXME: shush Sass warning spam, not relevant to testing Railties
+      Kernel.silence_warnings do
+        require File.expand_path('../../../../load_paths', __FILE__)
+      end
     end
   end
 end
@@ -327,5 +335,9 @@ Module.new do
   File.open("#{app_template_path}/config/boot.rb", 'w') do |f|
     f.puts "require '#{environment}'"
     f.puts "require 'rails/all'"
+
+    # Preempt the Bundler.require in config/application.rb and silence warning
+    # spam from our gem dependencies (👋 hello Sass 😁)
+    f.puts "Kernel.silence_warnings { Bundler.require(*Rails.groups) }"
   end
 end unless defined?(RAILS_ISOLATED_ENGINE)