- fix issue181: --pdb now also works on collect errors. This was

implemented by a slight internal refactoring and the introduction
  of a new hook ``pytest_exception_interact`` hook.

- fix issue341: introduce new experimental hook for IDEs/terminals to
  intercept debugging: ``pytest_exception_interact(node, call, report)``.

_pytest/__init__.py

@@ -1,2 +1,2 @@
 #
-__version__ = '2.4.0.dev11'
+__version__ = '2.4.0.dev12'

_pytest/core.py

@@ -298,7 +298,8 @@ class PluginManager(object):
             showlocals=getattr(option, 'showlocals', False),
             style=style,
         )
-        res = self.hook.pytest_internalerror(excrepr=excrepr)
+        res = self.hook.pytest_internalerror(excrepr=excrepr,
+                                             excinfo=excinfo)
         if not py.builtin.any(res):
             for line in str(excrepr).split("\n"):
                 sys.stderr.write("INTERNALERROR> %s\n" %line)

_pytest/hookspec.py

@@ -241,8 +241,18 @@ def pytest_plugin_registered(plugin, manager):
 def pytest_plugin_unregistered(plugin):
     """ a py lib plugin got unregistered. """
 
-def pytest_internalerror(excrepr):
+def pytest_internalerror(excrepr, excinfo):
     """ called for internal errors. """
 
 def pytest_keyboard_interrupt(excinfo):
     """ called for keyboard interrupt. """
+
+def pytest_exception_interact(node, call, report):
+    """ (experimental, new in 2.4) called when
+    an exception was raised which can potentially be
+    interactively handled.
+
+    This hook is only called if an exception was raised
+    that is not an internal exception like "skip.Exception".
+    """
+

_pytest/main.py

@@ -10,7 +10,7 @@ except ImportError:
     from UserDict import DictMixin as MappingMixin
 
 from _pytest.mark import MarkInfo
-import _pytest.runner
+from _pytest.runner import collect_one_node, Skipped
 
 tracebackcutdir = py.path.local(_pytest.__file__).dirpath()
 
@@ -372,7 +372,7 @@ class Collector(Node):
 
     # the set of exceptions to interpret as "Skip the whole module" during
     # collection
-    skip_exceptions = (_pytest.runner.Skipped,)
+    skip_exceptions = (Skipped,)
 
     class CollectError(Exception):
         """ an error during collection, contains a custom message. """
@@ -512,8 +512,7 @@ class Session(FSCollector):
             parts = self._parsearg(arg)
             self._initialparts.append(parts)
             self._initialpaths.add(parts[0])
-        self.ihook.pytest_collectstart(collector=self)
-        rep = self.ihook.pytest_make_collect_report(collector=self)
+        rep = collect_one_node(self)
         self.ihook.pytest_collectreport(report=rep)
         self.trace.root.indent -= 1
         if self._notfound:
@@ -642,8 +641,7 @@ class Session(FSCollector):
                     resultnodes.append(node)
                 continue
             assert isinstance(node, pytest.Collector)
-            node.ihook.pytest_collectstart(collector=node)
-            rep = node.ihook.pytest_make_collect_report(collector=node)
+            rep = collect_one_node(node)
             if rep.passed:
                 has_matched = False
                 for x in rep.result:
@@ -664,8 +662,7 @@ class Session(FSCollector):
             yield node
         else:
             assert isinstance(node, pytest.Collector)
-            node.ihook.pytest_collectstart(collector=node)
-            rep = node.ihook.pytest_make_collect_report(collector=node)
+            rep = collect_one_node(node)
             if rep.passed:
                 for subnode in rep.result:
                     for x in self.genitems(subnode):

_pytest/pdb.py

@@ -52,31 +52,26 @@ def pytest_runtest_makereport():
     pytestPDB.item = None
 
 class PdbInvoke:
-    @pytest.mark.tryfirst
-    def pytest_runtest_makereport(self, item, call, __multicall__):
-        rep = __multicall__.execute()
-        if not call.excinfo or \
-            call.excinfo.errisinstance(pytest.skip.Exception) or \
-            call.excinfo.errisinstance(py.std.bdb.BdbQuit):
-            return rep
-        if hasattr(rep, "wasxfail"):
-            return rep
-        return _enter_pdb(item, call.excinfo, rep)
+    def pytest_exception_interact(self, node, call, report):
+        return _enter_pdb(node, call.excinfo, report)
+
+    def pytest_internalerror(self, excrepr, excinfo):
+        for line in str(excrepr).split("\n"):
+            sys.stderr.write("INTERNALERROR> %s\n" %line)
+            sys.stderr.flush()
+        tb = _postmortem_traceback(excinfo)
+        post_mortem(tb)
 
 
-
-
-def _enter_pdb(item, excinfo, rep):
-    # we assume that the above execute() suspended capturing
+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 = item.config.pluginmanager.getplugin("terminalreporter")._tw
+    tw = node.config.pluginmanager.getplugin("terminalreporter")._tw
     tw.line()
     tw.sep(">", "traceback")
     rep.toterminal(tw)
     tw.sep(">", "entering PDB")
-
     tb = _postmortem_traceback(excinfo)
     post_mortem(tb)
     rep._pdbshown = True

_pytest/runner.py

@@ -108,8 +108,16 @@ def call_and_report(item, when, log=True, **kwds):
     report = hook.pytest_runtest_makereport(item=item, call=call)
     if log:
         hook.pytest_runtest_logreport(report=report)
+    if check_interactive_exception(call, report):
+        hook.pytest_exception_interact(node=item, call=call, report=report)
     return report
 
+def check_interactive_exception(call, report):
+    return call.excinfo and not (
+                hasattr(report, "wasxfail") or
+                call.excinfo.errisinstance(skip.Exception) or
+                call.excinfo.errisinstance(py.std.bdb.BdbQuit))
+
 def call_runtest_hook(item, when, **kwds):
     hookname = "pytest_runtest_" + when
     ihook = getattr(item.ihook, hookname)
@@ -268,8 +276,11 @@ def pytest_make_collect_report(collector):
             if not hasattr(errorinfo, "toterminal"):
                 errorinfo = CollectErrorRepr(errorinfo)
             longrepr = errorinfo
-    return CollectReport(collector.nodeid, outcome, longrepr,
+    rep = CollectReport(collector.nodeid, outcome, longrepr,
         getattr(call, 'result', None))
+    rep.call = call  # see collect_one_node
+    return rep
+
 
 class CollectReport(BaseReport):
     def __init__(self, nodeid, outcome, longrepr, result, sections=(), **extra):
@@ -364,6 +375,16 @@ class SetupState(object):
                 col._prepare_exc = sys.exc_info()
                 raise
 
+def collect_one_node(collector):
+    ihook = collector.ihook
+    ihook.pytest_collectstart(collector=collector)
+    rep = ihook.pytest_make_collect_report(collector=collector)
+    call = rep.__dict__.pop("call", None)
+    if call and check_interactive_exception(call, rep):
+        ihook.pytest_exception_interact(node=collector, call=call, report=rep)
+    return rep
+
+
 # =============================================================
 # Test OutcomeExceptions and helpers for creating them.