working with threads

lib/ember_cli/runner.rb

@@ -4,18 +4,20 @@ module EmberCli
   class Runner
     def initialize(out:, err:, env: {}, options: {})
       @env = env
-      @out_streams = Array(out)
-      @err_streams = Array(err)
+      @output_streams = Array(out)
+      @error_streams = Array(err)
       @options = options
+      @threads = []
     end
 
     def run(command)
       Open3.popen3(env, command, options) do |stdin, stdout, stderr, process|
         stdin.close
 
-        redirect(stdout, pipes: out_streams)
-        redirect(stderr, pipes: err_streams)
+        threads << redirect_stream_in_thread(stdout, write_to: output_streams)
+        threads << redirect_stream_in_thread(stderr, write_to: error_streams)
 
+        threads.each(&:join)
         process.value
       end
     end
@@ -30,17 +32,17 @@ def run!(command)
 
     protected
 
-    attr_reader :env, :err_streams, :options, :out_streams
+    attr_reader :env, :error_streams, :options, :output_streams, :threads
 
     private
 
-    def redirect(stream, pipes:)
-      pipes.each do |pipe|
-        # Thread.new do
-        #   Thread.current.abort_on_exception = true
-        #
-        IO.copy_stream(stream, pipe)
-        # end
+    def redirect_stream_in_thread(stream, write_to:)
+      Thread.new do
+        Thread.current.abort_on_exception = true
+
+        while line = stream.gets
+          write_to.each { |redirection_stream| redirection_stream.puts(line) }
+        end
       end
     end
   end

lib/ember_cli/shell.rb

@@ -85,7 +85,7 @@ def spawn(command)
     def runner
       Runner.new(
         options: { chdir: paths.root.to_s },
-        out: [$stdout, paths.log],
+        out: [$stdout, paths.log.open("a")],
         err: [$stderr],
         env: env,
       )