WIP

Author: 小野 直人

lib/debug/server.rb

@@ -77,6 +77,10 @@ def activate session, on_fork: false
           @q_msg = nil
           @q_ans.close
           @q_ans = nil
+          if CONFIG[:open_frontend] == 'chrome'
+            Process.kill(:KILL, @wait_thr.pid)
+            FileUtils.remove_entry_secure @dir
+          end
         end # accept
 
       rescue Terminate
@@ -108,8 +112,6 @@ def greeting
         @repl = false
         dap_setup @sock.read($1.to_i)
       when /^GET \/ HTTP\/1.1/
-        require_relative 'server_cdp'
-
         self.extend(UI_CDP)
         @repl = false
         @ws_server = UI_CDP::WebSocketServer.new(@sock)
@@ -271,6 +273,66 @@ def initialize host: nil, port: nil
       super()
     end
 
+    def chrome_setup
+      require 'open3'
+      require 'socket'
+      require 'tmpdir'
+
+      require_relative 'server_cdp'
+
+      # The process to check OS is based on `selenium` project.
+      case RbConfig::CONFIG['host_os']
+      when /mswin|msys|mingw|cygwin|bccwin|wince|emc/
+        chrome_path = 'chrome.exe'
+      when /darwin|mac os/
+        chrome_path = '/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome'
+      when /linux/
+        chrome_path = 'google-chrome'
+      else
+        raise "Unsupported OS"
+      end
+
+      @dir = Dir.mktmpdir
+      # The command line flags are based on: https://developer.mozilla.org/en-US/docs/Tools/Remote_Debugging/Chrome_Desktop#connecting
+      stdin, stdout, stderr, @wait_thr = *Open3.popen3("#{chrome_path} --remote-debugging-port=0 --no-first-run --no-default-browser-check --user-data-dir=#{@dir}")
+      stdin.close
+      stdout.close
+
+      data = stderr.readpartial 4096
+      if data.match /DevTools listening on ws:\/\/127.0.0.1:(\d+)\/(.*)/
+        port = $1
+        path = $2
+      else
+        raise "Can't open Chrome browser: #{data}"
+      end
+
+      s = Socket.tcp "127.0.0.1", port
+      ws_client = UI_CDP::WebSocketClient.new(s)
+      ws_client.handshake port, path
+      ws_client.send id: 1, method: 'Target.getTargets'
+
+      3.times do
+        res = ws_client.extract_data
+        case
+        when res['id'] == 1 && target_info = res.dig('result', 'targetInfos')
+          p = target_info.find{|t| t['type'] == 'page'}
+          ws_client.send id: 2, method: 'Target.attachToTarget',
+                        params: {
+                          targetId: p['targetId'],
+                          flatten: true
+                        }
+        when res['id'] == 2
+          sleep 0.1
+          s_id = res.dig('result', 'sessionId')
+          ws_client.send sessionId: s_id, id: 3,
+                        method: 'Page.navigate',
+                        params: {
+                          url: "devtools://devtools/bundled/inspector.html?ws=#{@addr}"
+                        }
+        end
+      end
+    end
+
     def accept
       retry_cnt = 0
       super # for fork
@@ -288,12 +350,7 @@ def accept
           #
           EOS
 
-          DEBUGGER__.warn <<~EOS if CONFIG[:open_frontend] == 'chrome'
-          With Chrome browser, type the following URL in the address-bar:
-          
-             devtools://devtools/bundled/inspector.html?ws=#{@addr}
-          
-          EOS
+          chrome_setup if CONFIG[:open_frontend] == 'chrome'
 
           Socket.accept_loop(socks) do |sock, client|
             @client_addr = client

lib/debug/server_cdp.rb

@@ -9,6 +9,77 @@ module DEBUGGER__
   module UI_CDP
     SHOW_PROTOCOL = ENV['RUBY_DEBUG_CDP_SHOW_PROTOCOL'] == '1'
 
+    class WebSocketClient
+      def initialize s
+        @sock = s
+      end
+
+      def handshake port, path
+        key = SecureRandom.hex(11)
+        @sock.print "GET /#{path} HTTP/1.1\r\nHost: 127.0.0.1:#{port}\r\nConnection: Upgrade\r\nUpgrade: websocket\r\nSec-WebSocket-Version: 13\r\nSec-WebSocket-Key: #{key}==\r\n\r\n"
+        res = @sock.readpartial 4092
+        if res.match /^Sec-WebSocket-Accept: (.*)\r\n/
+          correct_key = Base64.strict_encode64 Digest::SHA1.digest "#{key}==258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
+          raise "The Sec-WebSocket-Accept value: #{$1} is not valid" unless $1 == correct_key
+        else
+          raise "Unknown response: #{res}"
+        end
+      end
+
+      def send **msg
+        msg = JSON.generate(msg)
+        frame = []
+        fin = 0b10000000
+        opcode = 0b00000001
+        frame << fin + opcode
+      
+        mask = 0b10000000 # A client must mask all frames in a WebSocket Protocol.
+        bytesize = msg.bytesize
+        if bytesize < 126
+          payload_len = bytesize
+        elsif bytesize < 2 ** 16
+          payload_len = 0b01111110
+          ex_payload_len = [bytesize].pack('n*').bytes
+        else
+          payload_len = 0b01111111
+          ex_payload_len = [bytesize].pack('Q>').bytes
+        end
+      
+        frame << mask + payload_len
+        frame.push *ex_payload_len if ex_payload_len
+      
+        frame.push *masking_key = 4.times.map{rand(1..255)}
+        masked = []
+        msg.bytes.each_with_index do |b, i|
+          masked << (b ^ masking_key[i % 4])
+        end
+      
+        frame.push *masked
+        @sock.print frame.pack 'c*'
+      end
+
+      def extract_data
+        first_group = @sock.getbyte
+        fin = first_group & 0b10000000 != 128
+        raise 'Unsupported' if fin
+        opcode = first_group & 0b00001111
+        raise "Unsupported: #{opcode}" unless opcode == 1
+
+        second_group = @sock.getbyte
+        mask = second_group & 0b10000000 == 128
+        raise 'The server must not mask any frames' if mask
+        payload_len = second_group & 0b01111111
+        # TODO: Support other payload_lengths
+        if payload_len == 126
+          payload_len = @sock.read(2).unpack('n*')[0]
+        end
+
+        data = JSON.parse @sock.read payload_len
+        $stderr.puts '[>]' + data.inspect if SHOW_PROTOCOL
+        data
+      end
+    end
+
     class WebSocketServer
       def initialize s
         @sock = s