Allow loading webpack.config.ts if present (#524)

CHANGELOG.md

@@ -12,6 +12,7 @@ Changes since the last non-beta release.
 
 ### Changed
 - Changed internal `require`s to `require_relative` to make code less dependent on the load path. [PR 516](https://github.com/shakacode/shakapacker/pull/516) by [tagliala](https://github.com/tagliala).
+- Allow configuring webpack from a Typescript file (`config/webpack/webpack.config.ts`). [PR 524](https://github.com/shakacode/shakapacker/pull/524) by [jdelStrother](https://github.com/jdelStrother).
 
 ### Fixed
 - Fix error when rails environment is required from outside the rails root directory [PR 520](https://github.com/shakacode/shakapacker/pull/520)

README.md

@@ -675,6 +675,24 @@ module.exports = generateWebpackConfig({
 });
 ```
 
+Optionally, your webpack config file itself can be written in Typescript:
+
+``` bash
+npm install ts-node @types/node @types/webpack
+```
+
+```ts
+// config/webpack/webpack.config.ts
+import { generateWebpackConfig } from "shakapacker";
+import ForkTSCheckerWebpackPlugin from "fork-ts-checker-webpack-plugin";
+
+const config = generateWebpackConfig({
+  plugins: [new ForkTSCheckerWebpackPlugin()],
+});
+
+export default config;
+```
+
 #### CSS
 
 To enable CSS support in your application, add the following packages:

lib/shakapacker/runner.rb

@@ -15,19 +15,27 @@ def initialize(argv)
       @argv = argv
 
       @app_path              = File.expand_path(".", Dir.pwd)
-      @webpack_config        = File.join(@app_path, "config/webpack/webpack.config.js")
       @shakapacker_config    = ENV["SHAKAPACKER_CONFIG"] || File.join(@app_path, "config/shakapacker.yml")
-
-      unless File.exist?(@webpack_config)
-        $stderr.puts "webpack config #{@webpack_config} not found, please run 'bundle exec rails shakapacker:install' to install Shakapacker with default configs or add the missing config file for your custom environment."
-        exit!
-      end
+      @webpack_config        = find_webpack_config
 
       Shakapacker::Utils::Manager.error_unless_package_manager_is_obvious!
     end
 
     def package_json
       @package_json ||= PackageJson.read(@app_path)
     end
+
+    private
+      def find_webpack_config
+        possible_paths = %w[ts js].map do |ext|
+          File.join(@app_path, "config/webpack/webpack.config.#{ext}")
+        end
+        path = possible_paths.find { |f| File.exist?(f) }
+        unless path
+          $stderr.puts "webpack config #{possible_paths.last} not found, please run 'bundle exec rails shakapacker:install' to install Shakapacker with default configs or add the missing config file for your custom environment."
+          exit!
+        end
+        path
+      end
   end
 end

spec/shakapacker/webpack_runner_spec.rb

@@ -54,6 +54,17 @@
 
         verify_command(cmd, argv: (["--watch"]))
       end
+
+      it "loads webpack.config.ts if present" do
+        ts_config = "#{test_app_path}/config/webpack/webpack.config.ts"
+        FileUtils.touch(ts_config)
+
+        cmd = package_json.manager.native_exec_command("webpack", ["--config", ts_config])
+
+        verify_command(cmd)
+      ensure
+        FileUtils.rm(ts_config)
+      end
     end
   end