gh-102980: Redirect pdb interact command, add tests and improve docs

Doc/library/pdb.rst

@@ -570,10 +570,27 @@ can be overridden by the local file.
 
  Start an interactive interpreter (using the :mod:`code` module) whose global
  namespace contains all the (global and local) names found in the current
- scope.
+ scope. Use ``exit()`` or ``quit()`` to exit the interpreter and return to
+ the debugger.
+
+ .. note::
+
+ Because interact creates a new global namespace with the current global
+ and local namespace for execution, assignment to variables will not
+ affect the original namespaces.
+ However, modification to the mutable objects will be reflected in the
+ original namespaces.
 
  .. versionadded:: 3.2
 
+ .. versionadded:: 3.13
+ ``exit()`` and ``quit()`` can be used to exit :pdbcmd:`interact`
+ command.
+
+ .. versionchanged:: 3.13
+ :pdbcmd:`interact` directs its output to the debugger's
+ output channel rather than :data:`sys.stderr`.
+
 .. _debugger-aliases:
 
 .. pdbcommand:: alias [name [command]]

Lib/pdb.py

@@ -207,6 +207,15 @@ def namespace(self):
  )
 
 
+class _PdbInteractiveConsole(code.InteractiveConsole):
+ def __init__(self, ns, message):
+ self._message = message
+ super().__init__(locals=ns, local_exit=True)
+
+ def write(self, data):
+ self._message(data, end='')
+
+
 # Interaction prompt line will separate file and call info from code
 # text using value of line_prefix string. A newline and arrow may
 # be to your liking. You can set it once pdb is imported using the
@@ -672,8 +681,8 @@ def handle_command_def(self, line):
 
  # interface abstraction functions
 
- def message(self, msg):
- print(msg, file=self.stdout)
+ def message(self, msg, end='\n'):
+ print(msg, end=end, file=self.stdout)
 
  def error(self, msg):
  print('***', msg, file=self.stdout)
@@ -1786,7 +1795,9 @@ def do_interact(self, arg):
  contains all the (global and local) names found in the current scope.
  """
  ns = {**self.curframe.f_globals, **self.curframe_locals}
- code.interact("*interactive*", local=ns, local_exit=True)
+ console = _PdbInteractiveConsole(ns, message=self.message)
+ console.interact(banner="*pdb interact start*",
+ exitmsg="*exit from pdb interact command*")
 
  def do_alias(self, arg):
  """alias [name [command]]

Lib/test/test_pdb.py

@@ -778,6 +778,59 @@ def test_pdb_where_command():
  (Pdb) continue
  """
 
+def test_pdb_interact_command():
+ """Test interact command
+
+ >>> g = 0
+ >>> dict_g = {}
+
+ >>> def test_function():
+ ... x = 1
+ ... lst_local = []
+ ... import pdb; pdb.Pdb(nosigint=True, readrc=False).set_trace()
+
+ >>> with PdbTestInput([ # doctest: +ELLIPSIS, +NORMALIZE_WHITESPACE
+ ... 'interact',
+ ... 'x',
+ ... 'g',
+ ... 'x = 2',
+ ... 'g = 3',
+ ... 'dict_g["a"] = True',
+ ... 'lst_local.append(x)',
+ ... 'exit()',
+ ... 'p x',
+ ... 'p g',
+ ... 'p dict_g',
+ ... 'p lst_local',
+ ... 'continue',
+ ... ]):
+ ... test_function()
+ --Return--
+ > <doctest test.test_pdb.test_pdb_interact_command[2]>(4)test_function()->None
+ -> import pdb; pdb.Pdb(nosigint=True, readrc=False).set_trace()
+ (Pdb) interact
+ *pdb interact start*
+ ... x
+ 1
+ ... g
+ 0
+ ... x = 2
+ ... g = 3
+ ... dict_g["a"] = True
+ ... lst_local.append(x)
+ ... exit()
+ *exit from pdb interact command*
+ (Pdb) p x
+ 1
+ (Pdb) p g
+ 0
+ (Pdb) p dict_g
+ {'a': True}
+ (Pdb) p lst_local
+ [2]
+ (Pdb) continue
+ """
+
 def test_convenience_variables():
  """Test convenience variables
 

Misc/NEWS.d/next/Library/2023-10-23-03-49-34.gh-issue-102980.aXBd54.rst

@@ -0,0 +1 @@
+Redirect the output of ``interact`` command of :mod:`pdb` to the same channel as the debugger. Add tests and improve docs.