From 678c901bcfc6d40b6bed83d7f5dad75c0e1bddd8 Mon Sep 17 00:00:00 2001
From: Mihai Dinculescu <faithraven@gmail.com>
Date: Fri, 22 Jul 2016 15:58:47 +0000
Subject: [PATCH] Add Sprockets 4 support.

---
 lib/typescript-rails.rb             |  1 +
 lib/typescript/rails/railtie.rb     | 11 ++++++++++-
 lib/typescript/rails/transformer.rb | 20 ++++++++++++++++++++
 test/assets_test.rb                 |  8 ++++----
 4 files changed, 35 insertions(+), 5 deletions(-)
 create mode 100644 lib/typescript/rails/transformer.rb

diff --git a/lib/typescript-rails.rb b/lib/typescript-rails.rb
index 02e69e2..d5a0669 100644
--- a/lib/typescript-rails.rb
+++ b/lib/typescript-rails.rb
@@ -3,4 +3,5 @@
 require 'typescript/rails/engine'
 require 'typescript/rails/template'
 require 'typescript/rails/template_handler'
+require 'typescript/rails/transformer'
 require 'typescript/rails/version'
diff --git a/lib/typescript/rails/railtie.rb b/lib/typescript/rails/railtie.rb
index df58aa5..99f3524 100644
--- a/lib/typescript/rails/railtie.rb
+++ b/lib/typescript/rails/railtie.rb
@@ -4,8 +4,17 @@ class Typescript::Rails::Railtie < ::Rails::Railtie
   config.before_initialize do |app|
     if ::Rails::VERSION::MAJOR >= 4 || app.config.assets.enabled
       require 'typescript/rails/template'
+      require 'typescript/rails/transformer'
       require 'sprockets'
-      Sprockets.register_engine '.ts', Typescript::Rails::Template
+
+      if Sprockets.respond_to?(:register_engine)
+        Sprockets.register_engine '.ts', Typescript::Rails::Template, silence_deprecation: true
+      end
+
+      if Sprockets.respond_to?(:register_transformer)
+        Sprockets.register_mime_type 'text/typescript', extensions: ['.js.ts']
+        Sprockets.register_transformer 'text/typescript', 'application/javascript', Typescript::Rails::Transformer
+      end
     end
   end
 end
diff --git a/lib/typescript/rails/transformer.rb b/lib/typescript/rails/transformer.rb
new file mode 100644
index 0000000..263c237
--- /dev/null
+++ b/lib/typescript/rails/transformer.rb
@@ -0,0 +1,20 @@
+require 'typescript/rails'
+
+class Typescript::Rails::Transformer
+  def self.instance
+    @instance ||= new
+  end
+
+  def self.call(input)
+    instance.call(input)
+  end
+
+  def call(input)
+    filename = input[:filename]
+    source   = input[:data]
+    context  = input[:environment].context_class.new(input)
+
+    result = ::Typescript::Rails::Compiler.compile(filename, source, context)
+    { data: result }
+  end
+end
diff --git a/test/assets_test.rb b/test/assets_test.rb
index 6b543fa..23b28b6 100644
--- a/test/assets_test.rb
+++ b/test/assets_test.rb
@@ -41,8 +41,8 @@ def assets
   end
 
   test 'assets .js.ts is compiled from TypeScript to JavaScript' do
-    assert { assets['javascripts/hello'].present? }
-    assert { assets['javascripts/hello'].source.include?('var log_to_console = function (x) {') }
-    assert { assets['javascripts/hello'].source.include?('var s = "Hello, world!";') }
+    assert { assets['javascripts/hello.js'].present? }
+    assert { assets['javascripts/hello.js'].source.include?('var log_to_console = function (x) {') }
+    assert { assets['javascripts/hello.js'].source.include?('var s = "Hello, world!";') }
   end
-end
\ No newline at end of file
+end