Make assets precompile symlink task compatible with Rails 3

CHANGELOG.md

@@ -3,6 +3,10 @@ All notable changes to this project will be documented in this file. Items under
 
 Contributors: please follow the recommendations outlined at [keepachangelog.com](http://keepachangelog.com/). Please use the existing headings and styling as a guide, and add a link for the version diff at the bottom of the file. Also, please update the `Unreleased` link to compare to the latest release version.
 
+## [Unreleased]
+##### Fixed
+- Added compatibility with older manifest.yml files produced by Rails 3 Sprockets when symlinking digested assets during precompilation [#566](https://github.com/shakacode/react_on_rails/pull/566) by [etripier](https://github.com/etripier).
+
 ## [6.1.1] 2016-09-09
 ##### Fixed
 - React on Rails was incorrectly failing to create symlinks when a file existed in the location for the new symlink. [#491](https://github.com/shakacode/react_on_rails/pull/541) by [robwise ](https://github.com/robwise) and [justin808](https://github.com/justin808).

lib/react_on_rails/assets_precompile.rb

@@ -57,20 +57,26 @@ def symlink_non_digested_assets
       # directory with a digest, then the files are essentially "double-digested" and the CSS
       # references from webpack's CSS would be invalid. The fix is to symlink the double-digested
       # file back to the original digested name, and make a similar symlink for the gz version.
-      if @symlink_non_digested_assets_regex
+      return unless @symlink_non_digested_assets_regex
       manifest_glob = Dir.glob(@assets_path.join(".sprockets-manifest-*.json")) +
-                        Dir.glob(@assets_path.join("manifest-*.json"))
+                      Dir.glob(@assets_path.join("manifest-*.json")) +
+                      Dir.glob(@assets_path.join("manifest.yml"))
       if manifest_glob.empty?
-          puts "Warning: React On Rails: expected to find .sprockets-manifest-*.json or manifest-*.json "\
-                   "at #{@assets_path}, but found none. Canceling symlinking tasks."
+        puts "Warning: React On Rails: expected to find .sprockets-manifest-*.json, manifest-*.json "\
+                 "or manifest.yml at #{@assets_path}, but found none. Canceling symlinking tasks."
         return -1
       end
       manifest_path = manifest_glob.first
-        manifest_data = JSON.load(File.new(manifest_path))
+      manifest_file = File.new(manifest_path)
+      manifest_data = if File.extname(manifest_file) == ".json"
+                        JSON.load(manifest_file)["assets"]
+                      else
+                        YAML.load(manifest_file)
+                      end
 
       # We realize that we're copying other Rails assets that match the regexp, but this just
       # means that we'd be exposing the original, undigested names.
-        manifest_data["assets"].each do |original_filename, rails_digested_filename|
+      manifest_data.each do |original_filename, rails_digested_filename|
         # TODO: we should remove any original_filename that is NOT in the webpack deploy folder.
         next unless original_filename =~ @symlink_non_digested_assets_regex
         # We're symlinking from the digested filename back to the original filename which has
@@ -83,7 +89,6 @@ def symlink_non_digested_assets
         end
       end
     end
-    end
 
     def delete_broken_symlinks
       Dir.glob(@assets_path.join("*")).each do |filename|

spec/react_on_rails/assets_precompile_spec.rb

@@ -112,17 +112,36 @@ module ReactOnRails
       let(:digest_filename) { "alfa.12345.js" }
       let(:nondigest_filename) { "alfa.js" }
 
-      let(:checker) do
+      let(:create_json_manifest) do
         File.open(assets_path.join("manifest-alfa.json"), "w") do |f|
           f.write("{\"assets\":{\"#{nondigest_filename}\": \"#{digest_filename}\"}}")
         end
+      end
 
+      let(:create_yaml_manifest) do
+        File.open(assets_path.join("manifest.yml"), "w") do |f|
+          f.write("---\n#{nondigest_filename}: #{digest_filename}")
+        end
+      end
+
+      let(:checker) do
         AssetsPrecompile.new(assets_path: assets_path,
                              symlink_non_digested_assets_regex: Regexp.new('.*\.js$'))
       end
 
       it "creates a symlink with the original filename that points to the digested filename" do
         FileUtils.touch assets_path.join(digest_filename)
+        create_json_manifest
+        checker.symlink_non_digested_assets
+
+        expect(assets_path.join(nondigest_filename).lstat.symlink?).to be true
+        expect(File.identical?(assets_path.join(nondigest_filename),
+                               assets_path.join(digest_filename))).to be true
+      end
+
+      it "creates a symlink that points to the digested filename for the original filename found in the manifest.yml" do
+        FileUtils.touch assets_path.join(digest_filename)
+        create_yaml_manifest
         checker.symlink_non_digested_assets
 
         expect(assets_path.join(nondigest_filename).lstat.symlink?).to be true
@@ -133,6 +152,7 @@ module ReactOnRails
       it "creates a symlink with the original filename plus .gz that points to the gzipped digested filename" do
         FileUtils.touch assets_path.join(digest_filename)
         FileUtils.touch assets_path.join("#{digest_filename}.gz")
+        create_json_manifest
         checker.symlink_non_digested_assets
 
         expect(assets_path.join("#{nondigest_filename}.gz").lstat.symlink?).to be true