engine: make output Readline-friendly

lib/foreman/engine.rb

@@ -386,8 +386,16 @@ def handle_io(readers)
       if reader.eof?
         @readers.delete_if { |key, value| value == reader }
       else
-        data = reader.gets
-        output_with_mutex name_for(@readers.invert[reader]), data
+        $stdout.print marker(name_for(@readers.invert[reader]))
+
+        loop do
+          ch = reader.getc
+
+          $stdout.print ch
+          $stdout.flush
+
+          break if ch == "\n"
+        end
       end
     end
   end

lib/foreman/engine/cli.rb

@@ -55,18 +55,19 @@ def startup
 
   def output(name, data)
     data.to_s.lines.map(&:chomp).each do |message|
-      output  = ""
-      output += $stdout.color(@colors[name.split(".").first].to_sym)
-      output += "#{Time.now.strftime("%H:%M:%S")} #{pad_process_name(name)} | "
-      output += $stdout.color(:reset)
-      output += message
-      $stdout.puts output
-      $stdout.flush
+      $stdout.puts(marker(name) + message)
     end
   rescue Errno::EPIPE
     terminate_gracefully
   end
 
+  def marker(name)
+    output = ""
+    output += $stdout.color(@colors[name.split(".").first].to_sym)
+    output += "#{Time.now.strftime("%H:%M:%S")} #{pad_process_name(name)} | "
+    output += $stdout.color(:reset)
+  end
+
   def shutdown
   end
 

spec/foreman/cli_spec.rb

@@ -28,6 +28,23 @@
     end
 
     describe "with a valid Procfile" do
+      describe "Readline applications" do
+        it "outputs prompt" do
+          without_fakefs do
+            output = foreman("start irb -f #{resource_path("Procfile.IRB")}")
+            expect(output).to match(/irb\(main\):001:0>/)
+          end
+        end
+
+        it "outputs prompt and responds to input" do
+          without_fakefs do
+            output = foreman("start irbinput -f #{resource_path("Procfile.IRB")}")
+            expect(output).to match(/# leet foreman/)
+            expect(output).to match(/=> 74331/)
+          end
+        end
+      end
+
       it "can run a single command" do
         without_fakefs do
           output = foreman("start env -f #{resource_path("Procfile")}")

spec/resources/Procfile.IRB

@@ -0,0 +1,2 @@
+irb:      bin/irb
+irbinput: bin/irbinput

spec/resources/bin/irb

@@ -0,0 +1,5 @@
+#!/usr/bin/env ruby
+require 'irb'
+Thread.new { IRB.start }
+sleep 1
+abort

spec/resources/bin/irbinput

@@ -0,0 +1,16 @@
+#!/usr/bin/env ruby
+require 'pty'
+require 'irb'
+
+PTY.spawn('irb') do |reader, writer|
+  Thread.new do
+    sleep 1
+    writer.puts '0xf013 + 0x3248 # leet foreman'
+  end
+
+  loop do
+    sleep 2
+    print reader.sysread(256)
+    abort
+  end
+end