1 files changed, 65 insertions, 0 deletions
diff --git a/lib/gitlab/webpack/file_loader.rb b/lib/gitlab/webpack/file_loader.rb
new file mode 100644
index 00000000000..35ecb1eb4ed
--- /dev/null
+++ b/lib/gitlab/webpack/file_loader.rb
@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+require 'net/http'
+require 'uri'
+
+module Gitlab
+  module Webpack
+    class FileLoader
+      class BaseError < StandardError
+        attr_reader :original_error, :uri
+
+        def initialize(uri, orig)
+          super orig.message
+          @uri = uri.to_s
+          @original_error = orig
+        end
+      end
+
+      StaticLoadError = Class.new(BaseError)
+      DevServerLoadError = Class.new(BaseError)
+      DevServerSSLError = Class.new(BaseError)
+
+      def self.load(path)
+        if Gitlab.config.webpack.dev_server.enabled
+          self.load_from_dev_server(path)
+        else
+          self.load_from_static(path)
+        end
+      end
+
+      def self.load_from_dev_server(path)
+        host = Gitlab.config.webpack.dev_server.host
+        port = Gitlab.config.webpack.dev_server.port
+        scheme = Gitlab.config.webpack.dev_server.https ? 'https' : 'http'
+        uri = Addressable::URI.new(scheme: scheme, host: host, port: port, path: self.dev_server_path(path))
+
+        # localhost could be blocked via Gitlab::HTTP
+        response = HTTParty.get(uri.to_s, verify: false) # rubocop:disable Gitlab/HTTParty
+
+        return response.body if response.code == 200
+
+        raise "HTTP error #{response.code}"
+      rescue OpenSSL::SSL::SSLError, EOFError => e
+        raise DevServerSSLError.new(uri, e)
+      rescue StandardError => e
+        raise DevServerLoadError.new(uri, e)
+      end
+
+      def self.load_from_static(path)
+        file_uri = ::Rails.root.join(
+          Gitlab.config.webpack.output_dir,
+          path
+        )
+
+        File.read(file_uri)
+      rescue StandardError => e
+        raise StaticLoadError.new(file_uri, e)
+      end
+
+      def self.dev_server_path(path)
+        "/#{Gitlab.config.webpack.public_path}/#{path}"
+      end
+    end
+  end
+end