When the expression executed isn't exactly the same as the

recorded events (e.g. when parameter matchers are used), show in
the error message the real expression run, to aid in debugging.

3 files changed, 43 insertions, 7 deletions

diff --git a/NEWS b/NEWS
index a852ca6..e735ebe 100644
--- a/NEWS
+++ b/NEWS
@@ -29,6 +29,10 @@
 - Fixed problem when requesting order on similar expressions.  The
   second expression might not be accepted.
 
+- When the expression executed isn't exactly the same as the
+  recorded events (e.g. when parameter matchers are used), show in
+  the error message the real expression run, to aid in debugging.
+
 
 0.9.3 (2007-11-24)
 ==================
diff --git a/mocker.py b/mocker.py
index 0ee163b..813c0b8 100644
--- a/mocker.py
+++ b/mocker.py
@@ -684,13 +684,17 @@ class MockerBase(object):
                 recorder(self, event)
             return Mock(self, path)
         else:
-            # First run unsatisfied events, then ones not previously run.
-            events = [(event.satisfied()*2 + event.has_run(), event)
-                      for event in self._events]
-            events.sort()
-            for key, event in events:
-                if event.matches(path):
-                    return event.run(path)
+            # First run unsatisfied events, then ones not previously run. We
+            # put the index in the ordering tuple instead of the actual event
+            # because we want a stable sort (ordering between 2 events is
+            # undefined).
+            events = self._events
+            order = [(events[i].satisfied()*2 + events[i].has_run(), i)
+                     for i in range(len(events))]
+            order.sort()
+            for weight, i in order:
+                if events[i].matches(path):
+                    return events[i].run(path)
             raise MatchError(ERROR_PREFIX + "Unexpected expression: %s" % path)
 
     def get_recorders(cls, self):
@@ -1505,6 +1509,8 @@ class Event(object):
                     result = task_result
         if errors:
             message = [str(self.path)]
+            if str(path) != message[0]:
+                message.append("- Run: %s" % path)
             for error in errors:
                 lines = error.splitlines()
                 message.append("- " + lines.pop(0))
diff --git a/test.py b/test.py
index 10285aa..ca6e097 100755
--- a/test.py
+++ b/test.py
@@ -2624,6 +2624,31 @@ class EventTest(TestCase):
         self.assertEquals(calls, [42, 42, 42])
 
     def test_run_errors(self):
+        """When the path representation isn't the same it's shown up."""
+        class MyTask(object):
+            def __init__(self, id, failed):
+                self.id = id
+                self.failed = failed
+            def run(self, path):
+                if self.failed:
+                    raise AssertionError("%d failed" % self.id)
+        event = Event("i.am.a.path")
+        event.add_task(MyTask(1, True))
+        event.add_task(MyTask(2, False))
+        event.add_task(MyTask(3, True))
+
+        try:
+            event.run("i.am.a.path")
+        except AssertionError, e:
+            message = os.linesep.join(["i.am.a.path",
+                                       "- 1 failed",
+                                       "- 3 failed"])
+            self.assertEquals(str(e), message)
+        else:
+            self.fail("AssertionError not raised")
+
+    def test_run_errors_with_different_path_representation(self):
+        """When the path representation isn't the same it's shown up."""
         class MyTask(object):
             def __init__(self, id, failed):
                 self.id = id
@@ -2640,6 +2665,7 @@ class EventTest(TestCase):
             event.run(42)
         except AssertionError, e:
             message = os.linesep.join(["i.am.a.path",
+                                       "- Run: 42", # <==
                                        "- 1 failed",
                                        "- 3 failed"])
             self.assertEquals(str(e), message)