feat(React::JSX) decouple transformer class

Author: rmosolgo

lib/react/jsx.rb

@@ -5,15 +5,22 @@
 
 module React
   module JSX
-    mattr_accessor :transform_options
+    mattr_accessor :transform_options, :transformer_class
+
+    # You can assign `React::JSX.transformer_class = `
+    # to provide your own transformer. It must implement:
+    # - #initialize(options)
+    # - #transform(code) => new code
+    self.transformer_class = Transformer
+
     def self.transform(code)
       transformer.transform(code)
     end
 
     def self.transformer
       # lazily loaded during first request and reloaded every time when in dev or test
       if @transformer.nil? || !::Rails.env.production?
-        @transformer = Transformer.new(transform_options)
+        @transformer = transformer_class.new(transform_options)
       end
       @transformer
     end

test/react/jsx_test.rb

@@ -20,13 +20,26 @@
 }).call(this);
 eos
 
+class NullTransformer
+  def initialize(options={}); end
+  def transform(code)
+    "TRANSFORMED CODE!;\n"
+  end
+end
+
 class JSXTransformTest < ActionDispatch::IntegrationTest
-  setup { clear_sprockets_cache }
-  teardown { clear_sprockets_cache }
+  setup do
+    clear_sprockets_cache
+  end
+
+  teardown do
+    clear_sprockets_cache
+    React::JSX.transformer_class = React::JSX::Transformer
+    React::JSX.transform_options = {}
+  end
 
   test 'asset pipeline should transform JSX' do
     get '/assets/example.js'
-    FileUtils.rm_r CACHE_PATH if CACHE_PATH.exist?
     assert_response :success
     assert_equal EXPECTED_JS, @response.body
   end
@@ -85,4 +98,11 @@ class JSXTransformTest < ActionDispatch::IntegrationTest
     assert_response :success
     assert_equal 'test_confirmation_token_jsx_transformed;', @response.body
   end
+
+  test 'use a custom transformer' do
+    React::JSX.transformer_class = NullTransformer
+    manually_expire_asset('example2.js')
+    get '/assets/example2.js'
+    assert_equal "TRANSFORMED CODE!;\n", @response.body
+  end
 end

test/react_test.rb

@@ -12,13 +12,7 @@ class ReactTest < ActionDispatch::IntegrationTest
     app_react_file_path = File.expand_path("../dummy/vendor/assets/javascripts/react.js",  __FILE__)
     react_file_token = "'test_confirmation_token_react_content_non_production';\n"
     File.write(app_react_file_path, react_file_token)
-
-    react_asset = Rails.application.assets['react.js']
-
-    # Sprockets 2 doesn't expire this asset correctly,
-    # so override `fresh?` to mark it as expired.
-    def react_asset.fresh?(env); false; end
-
+    manually_expire_asset("react.js")
     react_asset = Rails.application.assets['react.js']
 
     get '/assets/react.js'

test/test_helper.rb

@@ -19,6 +19,14 @@ def clear_sprockets_cache
   end
 end
 
+# Sprockets 2 doesn't expire this assets well in
+# this kind of setting,
+# so override `fresh?` to mark it as expired.
+def manually_expire_asset(asset_name)
+  asset = Rails.application.assets[asset_name]
+  def asset.fresh?(env); false; end
+end
+
 # Load support files
 Dir["#{File.dirname(__FILE__)}/support/**/*.rb"].each { |f| require f }