added subdir generator test and updated readme

Author: matt-potter

README.md

@@ -87,6 +87,12 @@ $ rails g react:component HelloWorld greeting:string
 
 Your component is added to `app/javascript/components/` by default.
 
+You can also generate your component in a subdirectory:
+
+```
+$ rails g react:component my_subdirectory/HelloWorld greeting:string
+```
+
 [Render it in a Rails view](#view-helper):
 
 ```erb
@@ -135,7 +141,7 @@ $ bundle exec rails webpacker:install:typescript
 $ yarn add @types/react @types/react-dom
 ```
 
-Doing this will allow React-Rails to support the .tsx extension. 
+Doing this will allow React-Rails to support the .tsx extension.
 
 ## Use with Asset Pipeline
 

test/generators/component_generator_test.rb

@@ -10,10 +10,16 @@ class ComponentGeneratorTest < Rails::Generators::TestCase
     def filename
       'app/javascript/components/GeneratedComponent.js'
     end
+    def filename_with_subfolder
+      'app/javascript/components/generated_folder/GeneratedComponent.js'
+    end
   else
     def filename
       'app/assets/javascripts/components/generated_component.js.jsx'
     end
+    def filename_with_subfolder
+      'app/assets/javascripts/components/generated_folder/generated_component.js.jsx'
+    end
   end
 
   test 'creates the component file' do
@@ -27,6 +33,17 @@ def filename
     end
   end
 
+  test 'creates the component file in a subdirectory' do
+    puts WebpackerHelpers.available?
+    run_generator %w(generated_folder/GeneratedComponent)
+    assert_file filename_with_subfolder do |contents|
+      if WebpackerHelpers.available?
+        assert_match /^import React from "react"/, contents
+        assert_match /export default GeneratedComponent\n$/m, contents
+      end
+    end
+  end
+
   test 'creates the component file with a node argument' do
     run_generator %w(GeneratedComponent name)
     assert_file filename, %r{name: PropTypes.node}