Merge branch 'upgrade-to-webpack-v4' into 'master'

Upgrade to Webpack 4

Closes #43400

See merge request gitlab-org/gitlab-ce!17218

2 files changed, 29 insertions, 2 deletions

diff --git a/lib/gitlab/middleware/webpack_proxy.rb b/lib/gitlab/webpack/dev_server_middleware.rb
index 6aecf63231f..b9a75eaac63 100644
--- a/lib/gitlab/middleware/webpack_proxy.rb
+++ b/lib/gitlab/webpack/dev_server_middleware.rb
@@ -3,8 +3,8 @@
 
 # :nocov:
 module Gitlab
-  module Middleware
-    class WebpackProxy < Rack::Proxy
+  module Webpack
+    class DevServerMiddleware < Rack::Proxy
       def initialize(app = nil, opts = {})
         @proxy_host = opts.fetch(:proxy_host, 'localhost')
         @proxy_port = opts.fetch(:proxy_port, 3808)
diff --git a/lib/gitlab/webpack/manifest.rb b/lib/gitlab/webpack/manifest.rb
new file mode 100644
index 00000000000..0c343e5bc1d
--- /dev/null
+++ b/lib/gitlab/webpack/manifest.rb
@@ -0,0 +1,27 @@
+require 'webpack/rails/manifest'
+
+module Gitlab
+  module Webpack
+    class Manifest < ::Webpack::Rails::Manifest
+      # Raised if a supplied asset does not exist in the webpack manifest
+      AssetMissingError = Class.new(StandardError)
+
+      class << self
+        def entrypoint_paths(source)
+          raise ::Webpack::Rails::Manifest::WebpackError, manifest["errors"] unless manifest_bundled?
+
+          entrypoint = manifest["entrypoints"][source]
+          if entrypoint && entrypoint["assets"]
+            # Can be either a string or an array of strings.
+            # Do not include source maps as they are not javascript
+            [entrypoint["assets"]].flatten.reject { |p| p =~ /.*\.map$/ }.map do |p|
+              "/#{::Rails.configuration.webpack.public_path}/#{p}"
+            end
+          else
+            raise AssetMissingError, "Can't find entry point '#{source}' in webpack manifest"
+          end
+        end
+      end
+    end
+  end
+end