path: root/contrib/python/pytest/py2/_pytest/debugging.py

# -*- coding: utf-8 -*- 
""" interactive debugging with PDB, the Python Debugger. """
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

import os
import argparse 
import pdb
import sys
from doctest import UnexpectedException

from _pytest import outcomes
from _pytest.config import hookimpl
from _pytest.config.exceptions import UsageError 


def import_readline():
    try:
        import readline
    except ImportError:
        sys.path.append('/usr/lib/python2.7/lib-dynload')

    try:
        import readline
    except ImportError as e:
        print('can not import readline:', e)

        import subprocess
        try:
            subprocess.check_call('stty icrnl'.split())
        except OSError as e:
            print('can not restore Enter, use Control+J:', e)


def tty():
    if os.isatty(1):
        return

    fd = os.open('/dev/tty', os.O_RDWR)
    os.dup2(fd, 0)
    os.dup2(fd, 1)
    os.dup2(fd, 2)
    os.close(fd)

    old_sys_path = sys.path
    sys.path = list(sys.path)
    try:
        import_readline()
    finally:
        sys.path = old_sys_path


def _validate_usepdb_cls(value): 
    """Validate syntax of --pdbcls option.""" 
    try: 
        modname, classname = value.split(":") 
    except ValueError: 
        raise argparse.ArgumentTypeError( 
            "{!r} is not in the format 'modname:classname'".format(value) 
        ) 
    return (modname, classname) 
 
 
def pytest_addoption(parser):
    group = parser.getgroup("general")
    group._addoption(
        "--pdb",
        dest="usepdb",
        action="store_true",
        help="start the interactive Python debugger on errors or KeyboardInterrupt.",
    )
    group._addoption(
        "--pdbcls",
        dest="usepdb_cls",
        metavar="modulename:classname",
        type=_validate_usepdb_cls, 
        help="start a custom interactive Python debugger on errors. "
        "For example: --pdbcls=IPython.terminal.debugger:TerminalPdb",
    )
    group._addoption(
        "--trace",
        dest="trace",
        action="store_true",
        help="Immediately break when running each test.",
    )


def pytest_configure(config):
    if config.getvalue("trace"):
        config.pluginmanager.register(PdbTrace(), "pdbtrace")
    if config.getvalue("usepdb"):
        config.pluginmanager.register(PdbInvoke(), "pdbinvoke")

    pytestPDB._saved.append(
        (pdb.set_trace, pytestPDB._pluginmanager, pytestPDB._config) 
    )
    pdb.set_trace = pytestPDB.set_trace
    pytestPDB._pluginmanager = config.pluginmanager
    pytestPDB._config = config

    # NOTE: not using pytest_unconfigure, since it might get called although
    #       pytest_configure was not (if another plugin raises UsageError).
    def fin():
        (
            pdb.set_trace,
            pytestPDB._pluginmanager,
            pytestPDB._config,
        ) = pytestPDB._saved.pop()

    config._cleanup.append(fin)


class pytestPDB(object):
    """ Pseudo PDB that defers to the real pdb. """

    _pluginmanager = None
    _config = None
    _saved = []
    _recursive_debug = 0 
    _wrapped_pdb_cls = None 

    @classmethod
    def _is_capturing(cls, capman): 
        if capman: 
            return capman.is_capturing() 
        return False 
 
    @classmethod 
    def _import_pdb_cls(cls, capman): 
        if not cls._config: 
            # Happens when using pytest.set_trace outside of a test. 
            return pdb.Pdb 
 
        usepdb_cls = cls._config.getvalue("usepdb_cls") 
 
        if cls._wrapped_pdb_cls and cls._wrapped_pdb_cls[0] == usepdb_cls: 
            return cls._wrapped_pdb_cls[1] 
 
        if usepdb_cls: 
            modname, classname = usepdb_cls 
 
            try: 
                __import__(modname) 
                mod = sys.modules[modname] 
 
                # Handle --pdbcls=pdb:pdb.Pdb (useful e.g. with pdbpp). 
                parts = classname.split(".") 
                pdb_cls = getattr(mod, parts[0]) 
                for part in parts[1:]: 
                    pdb_cls = getattr(pdb_cls, part) 
            except Exception as exc: 
                value = ":".join((modname, classname)) 
                raise UsageError( 
                    "--pdbcls: could not import {!r}: {}".format(value, exc) 
                ) 
        else: 
            pdb_cls = pdb.Pdb 
 
        wrapped_cls = cls._get_pdb_wrapper_class(pdb_cls, capman) 
        cls._wrapped_pdb_cls = (usepdb_cls, wrapped_cls) 
        return wrapped_cls 
 
    @classmethod 
    def _get_pdb_wrapper_class(cls, pdb_cls, capman): 
        import _pytest.config

        class PytestPdbWrapper(pdb_cls, object): 
            _pytest_capman = capman 
            _continued = False 

            def do_debug(self, arg): 
                cls._recursive_debug += 1 
                ret = super(PytestPdbWrapper, self).do_debug(arg) 
                cls._recursive_debug -= 1 
                return ret 

            def do_continue(self, arg): 
                ret = super(PytestPdbWrapper, self).do_continue(arg) 
                if cls._recursive_debug == 0: 
                    tw = _pytest.config.create_terminal_writer(cls._config) 
                    tw.line() 
 
                    capman = self._pytest_capman 
                    capturing = pytestPDB._is_capturing(capman) 
                    if capturing: 
                        if capturing == "global": 
                            tw.sep(">", "PDB continue (IO-capturing resumed)")
                        else:
                            tw.sep( 
                                ">", 
                                "PDB continue (IO-capturing resumed for %s)" 
                                % capturing, 
                            ) 
                        capman.resume() 
                    else: 
                        tw.sep(">", "PDB continue") 
                cls._pluginmanager.hook.pytest_leave_pdb(config=cls._config, pdb=self) 
                self._continued = True 
                return ret 

            do_c = do_cont = do_continue 

            def do_quit(self, arg): 
                """Raise Exit outcome when quit command is used in pdb. 

                This is a bit of a hack - it would be better if BdbQuit 
                could be handled, but this would require to wrap the 
                whole pytest run, and adjust the report etc. 
                """ 
                ret = super(PytestPdbWrapper, self).do_quit(arg) 

                if cls._recursive_debug == 0: 
                    outcomes.exit("Quitting debugger") 
 
                return ret 
 
            do_q = do_quit 
            do_exit = do_quit 
 
            def setup(self, f, tb): 
                """Suspend on setup(). 
 
                Needed after do_continue resumed, and entering another 
                breakpoint again. 
                """ 
                ret = super(PytestPdbWrapper, self).setup(f, tb) 
                if not ret and self._continued: 
                    # pdb.setup() returns True if the command wants to exit 
                    # from the interaction: do not suspend capturing then. 
                    if self._pytest_capman: 
                        self._pytest_capman.suspend_global_capture(in_=True) 
                return ret 
 
            def get_stack(self, f, t): 
                stack, i = super(PytestPdbWrapper, self).get_stack(f, t) 
                if f is None: 
                    # Find last non-hidden frame. 
                    i = max(0, len(stack) - 1) 
                    while i and stack[i][0].f_locals.get("__tracebackhide__", False): 
                        i -= 1 
                return stack, i 
 
        return PytestPdbWrapper 
 
    @classmethod 
    def _init_pdb(cls, method, *args, **kwargs): 
        """ Initialize PDB debugging, dropping any IO capturing. """ 
        import _pytest.config 
 
        if cls._pluginmanager is not None: 
            capman = cls._pluginmanager.getplugin("capturemanager") 
        else:
            capman = None 
        if capman: 
            capman.suspend(in_=True) 

        if cls._config: 
            tw = _pytest.config.create_terminal_writer(cls._config) 
            tw.line() 

            if cls._recursive_debug == 0: 
                # Handle header similar to pdb.set_trace in py37+. 
                header = kwargs.pop("header", None) 
                if header is not None: 
                    tw.sep(">", header) 
                else: 
                    capturing = cls._is_capturing(capman) 
                    if capturing == "global": 
                        tw.sep(">", "PDB %s (IO-capturing turned off)" % (method,)) 
                    elif capturing: 
                        tw.sep( 
                            ">", 
                            "PDB %s (IO-capturing turned off for %s)" 
                            % (method, capturing), 
                        ) 
                    else: 
                        tw.sep(">", "PDB %s" % (method,)) 

        _pdb = cls._import_pdb_cls(capman)(**kwargs) 
 
        if cls._pluginmanager: 
            cls._pluginmanager.hook.pytest_enter_pdb(config=cls._config, pdb=_pdb) 
        return _pdb 
 
    @classmethod 
    def set_trace(cls, *args, **kwargs): 
        """Invoke debugging via ``Pdb.set_trace``, dropping any IO capturing.""" 
        tty() 
        frame = sys._getframe().f_back 
        _pdb = cls._init_pdb("set_trace", *args, **kwargs) 
        _pdb.set_trace(frame) 
 
 
class PdbInvoke(object):
    def pytest_exception_interact(self, node, call, report):
        capman = node.config.pluginmanager.getplugin("capturemanager")
        if capman:
            capman.suspend_global_capture(in_=True)
            out, err = capman.read_global_capture()
            sys.stdout.write(out)
            sys.stdout.write(err)
        tty()
        _enter_pdb(node, call.excinfo, report)

    def pytest_internalerror(self, excrepr, excinfo):
        tb = _postmortem_traceback(excinfo)
        post_mortem(tb)


class PdbTrace(object):
    @hookimpl(hookwrapper=True)
    def pytest_pyfunc_call(self, pyfuncitem):
        _test_pytest_function(pyfuncitem)
        yield


def _test_pytest_function(pyfuncitem):
    _pdb = pytestPDB._init_pdb("runcall") 
    testfunction = pyfuncitem.obj
    pyfuncitem.obj = _pdb.runcall 
    if "func" in pyfuncitem._fixtureinfo.argnames:  # pragma: no branch 
        raise ValueError("--trace can't be used with a fixture named func!") 
    pyfuncitem.funcargs["func"] = testfunction 
    new_list = list(pyfuncitem._fixtureinfo.argnames) 
    new_list.append("func") 
    pyfuncitem._fixtureinfo.argnames = tuple(new_list) 


def _enter_pdb(node, excinfo, rep):
    # XXX we re-use the TerminalReporter's terminalwriter
    # because this seems to avoid some encoding related troubles
    # for not completely clear reasons.
    tw = node.config.pluginmanager.getplugin("terminalreporter")._tw
    tw.line()

    showcapture = node.config.option.showcapture

    for sectionname, content in (
        ("stdout", rep.capstdout),
        ("stderr", rep.capstderr),
        ("log", rep.caplog),
    ):
        if showcapture in (sectionname, "all") and content:
            tw.sep(">", "captured " + sectionname)
            if content[-1:] == "\n":
                content = content[:-1]
            tw.line(content)

    tw.sep(">", "traceback")
    rep.toterminal(tw)
    tw.sep(">", "entering PDB")
    tb = _postmortem_traceback(excinfo)
    rep._pdbshown = True
    post_mortem(tb) 
    return rep


def _postmortem_traceback(excinfo):
    if isinstance(excinfo.value, UnexpectedException):
        # A doctest.UnexpectedException is not useful for post_mortem.
        # Use the underlying exception instead:
        return excinfo.value.exc_info[2]
    else:
        return excinfo._excinfo[2]


def post_mortem(t):
    p = pytestPDB._init_pdb("post_mortem") 
    p.reset()
    p.interaction(None, t)
    if p.quitting: 
        outcomes.exit("Quitting debugger")