RELAND of Cross-repo recipe package system.

third_party/recipe_engine/expect_tests/handle_debug.py

-# Copyright 2014 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-import sys
-import pdb
-
-from .type_definitions import Handler
-
-
-class DebugHandler(Handler):
-  """Execute each test under the pdb debugger."""
-  SKIP_RUNLOOP = True
-
-  class ResultStageHandler(Handler.ResultStageHandler):
-    @staticmethod
-    def handle_MultiTest(mtest):
-      for _ in mtest.process(DebugHandler.ResultStageHandler.handle_Test):
-        pass
-
-    @staticmethod
-    def handle_Test(test):
-      dbg = pdb.Pdb()
-      for path, line, funcname in test.breakpoints:
-        dbg.set_break(path, line, funcname=funcname)
-
-      dbg.reset()
-
-      def dispatch_thunk(*args):
-        """Allows us to continue until the actual breakpoint."""
-        val = dbg.trace_dispatch(*args)
-        dbg.set_continue()
-        sys.settrace(dbg.trace_dispatch)
-        return val
-      sys.settrace(dispatch_thunk)
-      try:
-        test.run()
-      except pdb.bdb.BdbQuit:
-        pass
-      finally:
-        dbg.quitting = 1
-        sys.settrace(None)