Handle output in stderr gracefully when discovering tests

README.rst

@@ -50,3 +50,29 @@ packge. If you're using Python 2.7 on Ubuntu 13.04, you can install
 
 For other versions of Python and Ubuntu, you'll need to adjust this as
 appropriate.
+
+Development
+-----------
+
+The recommended way of setting up your development envrionment for ``cricket``
+is to install a virtual environment, install the required dependencies and
+start coding. Assuming that you are using ``virtualenvwrapper``, you only have
+to run::
+
+    $ git clone git@github.com:freakboy3742/cricket.git
+    $ cde cricket
+    $ mkvirtualenv cricket
+
+Cricket uses ``unittest`` (or ``unittest2`` for Python < 2.7) for its own test
+suite as well as additional helper modules for testing. To install all the
+requirements for cricket, you have to run the following commands within your
+virutal envrionment::
+
+    $ pip install -e .
+    $ pip install -r requirements_dev.txt
+
+In case you are running a python version ``< 2.7`` please use the
+``requirements_dev_python2.7.txt`` instead because ``unittest2`` is not part
+of the standard library for these version.
+
+Now you are ready to start hacking! Have fun!

cricket/compat.py

@@ -0,0 +1,13 @@
+# This is for backwards compatibility with Python version < 2.7 only
+# for Python 2.7 and 3.x the default unittest is the correct package
+# to use. unittest2 is a backport of this package to be used in
+# versions < 2.7.
+# Use
+#       from cricket.compat import unittest
+#
+# to make versions work with all version of Python. This will be slowly
+# deprecated in the future as Python < 2.7 becomes more and mor
+# obsolete.
+import unittest
+if not hasattr(unittest.TestCase, 'assertIsNotNone'):
+    import unittest2 as unittest

cricket/django/__main__.py

@@ -1,6 +1,7 @@
 from Tkinter import *
 
-from cricket.view import MainWindow, TestLoadErrorDialog
+from cricket.view import (MainWindow, TestLoadErrorDialog,
+                          IgnorableTestLoadErrorDialog)
 from cricket.model import ModelLoadError
 from cricket.django.model import DjangoProject
 
@@ -23,6 +24,11 @@ def main():
             if dialog.status == dialog.CANCEL:
                 sys.exit(1)
 
+    if project.errors:
+        dialog = IgnorableTestLoadErrorDialog(root, '\n'.join(project.errors))
+        if dialog.status == dialog.CANCEL:
+            sys.exit(1)
+
     # Set the project for the main window.
     # This populates the tree, and sets listeners for
     # future tree modifications.

cricket/model.py

@@ -380,7 +380,7 @@ class Project(dict, EventSource):
     """
     def __init__(self):
         super(Project, self).__init__()
-
+        self.errors = []
         self.discover_tests()
 
     def __repr__(self):
@@ -458,12 +458,11 @@ def discover_tests(self):
         for line in runner.stdout:
             test_list.append(line.strip())
 
-        errors = []
         for line in runner.stderr:
-            errors.append(line.strip())
+            self.errors.append(line.strip())
 
-        if errors:
-            raise ModelLoadError('\n'.join(errors))
+        if self.errors and not test_list:
+            raise ModelLoadError('\n'.join(self.errors))
 
         self.refresh(test_list)
 

cricket/view.py

@@ -940,8 +940,35 @@ def __init__(self, parent, trace):
             self,
             parent,
             'Error discovering test suite',
-            'The following stack trace was generated when attempting to discover the test suite:',
+            ('The following stack trace was generated when attempting to '
+             'discover the test suite:'),
             trace,
             button_text='Retry',
             cancel_text='Quit',
         )
+
+    def cancel(self, event=None):
+        StackTraceDialog.cancel(self, event=event)
+        self.parent.quit()
+
+
+class IgnorableTestLoadErrorDialog(StackTraceDialog):
+    def __init__(self, parent, trace):
+        '''Show a dialog with a scrollable stack trace when loading
+           tests turned up errors in stderr but they can safely be ignored.
+
+        Arguments:
+
+            parent -- a parent window (the application window)
+            trace -- the stack trace content to display.
+        '''
+        StackTraceDialog.__init__(
+            self,
+            parent,
+            'Error discovering test suite',
+            ('The following error where captured during test discovery '
+             'but running the tests might still work:'),
+            trace,
+            button_text='Continue',
+            cancel_text='Quit',
+        )

requirements_dev.txt

@@ -0,0 +1 @@
+mock==1.0.1

requirements_dev_python2.6.txt

@@ -0,0 +1,2 @@
+-r requirements_dev.txt
+unittest2==0.5.1

tests/model_tests.py

@@ -0,0 +1,51 @@
+import mock
+
+from cricket.compat import unittest
+from cricket.model import Project, ModelLoadError
+
+
+class TestProject(unittest.TestCase):
+
+    def setUp(self):
+        super(TestProject, self).setUp()
+        Project.discover_commandline = mock.MagicMock()
+
+        self.test_list = [
+            'tests.FunkyTestCase.test_something_unnecessary',
+            'more_tests.FunkyTestCase.test_this_doesnt_make_sense',
+        ]
+        self.error_list = [
+            'ERROR: you broke it, fool!',
+        ]
+
+    @mock.patch('cricket.model.subprocess.Popen')
+    def test_project_has_error_list_from_stderr(self, sub_mock):
+        io_mock = mock.MagicMock()
+        io_mock.stdout = self.test_list
+        io_mock.stderr = self.error_list
+        sub_mock.return_value = io_mock
+
+        project = Project()
+
+        self.assertEquals(project.errors, self.error_list)
+        self.assertItemsEqual(project.keys(), ['tests', 'more_tests'])
+
+    @mock.patch('cricket.model.subprocess.Popen')
+    def test_raises_exception_when_errors_no_tests(self, sub_mock):
+        io_mock = mock.MagicMock()
+        io_mock.stdout = []
+        io_mock.stderr = self.error_list
+        sub_mock.return_value = io_mock
+
+        self.assertRaises(ModelLoadError, Project)
+
+    @mock.patch('cricket.model.subprocess.Popen')
+    def test_finds_test_modules_without_errors(self, sub_mock):
+        io_mock = mock.MagicMock()
+        io_mock.stdout = self.test_list
+        io_mock.stderr = []
+        sub_mock.return_value = io_mock
+
+        project = Project()
+        self.assertEquals(project.errors, [])
+        self.assertItemsEqual(project.keys(), ['tests', 'more_tests'])