Add CDP's disconnection test

Author: st0012

test/protocol/disconnect_cdp_test.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+require_relative '../support/protocol_test_case'
+
+module DEBUGGER__
+  class DisconnectCDPTest < ProtocolTestCase
+    PROGRAM = <<~RUBY
+       1| module Foo
+       2|   class Bar
+       3|     def self.a
+       4|       "hello"
+       5|     end
+       6|   end
+       7|   loop do
+       8|     b = 1
+       9|   end
+      10|   Bar.a
+      11|   bar = Bar.new
+      12| end
+    RUBY
+
+    def test_closing_cdp_connection_doesnt_kill_the_debuggee
+      run_protocol_scenario PROGRAM, dap: false do
+        req_disconnect
+        attach_to_cdp_server
+        req_terminate_debuggee
+      end
+    end
+  end
+end

test/support/protocol_test_case.rb

@@ -318,6 +318,7 @@ def execute_cdp_scenario scenario
       @backlog = []
 
       attach_to_cdp_server
+      assert_cdp_connected
       scenario.call
 
       flunk create_protocol_message "Expected the debuggee program to finish" unless wait_pid @remote_info.pid, TIMEOUT_SEC
@@ -412,6 +413,9 @@ def attach_to_cdp_server
       sleep 0.001 while @reader_thread.status != 'sleep'
       @reader_thread.run
       INITIALIZE_CDP_MSGS.each{|msg| send(**msg)}
+    end
+
+    def assert_cdp_connected
       res = find_response :method, 'Debugger.paused', 'C<D'
       @crt_frames = res.dig(:params, :callFrames)
     end