Merge pull request #951 from LewisHaley/fix-test-repr-with-mutable-args

Fix test repr with mutable args

nose/case.py

@@ -199,7 +199,7 @@ def runTest(self):
     def shortDescription(self):
         if hasattr(self.test, 'description'):
             return self.test.description
-        func, arg = self._descriptors()
+        func = self._descriptor()
         doc = getattr(func, '__doc__', None)
         if not doc:
             doc = str(self)
@@ -239,6 +239,7 @@ def __init__(self, test, setUp=None, tearDown=None, arg=tuple(),
         self.setUpFunc = setUp
         self.tearDownFunc = tearDown
         self.arg = arg
+        self.arg_repr = repr(self.arg)
         self.descriptor = descriptor
         TestBase.__init__(self)
 
@@ -276,32 +277,27 @@ def tearDown(self):
             try_run(self.test, names)
 
     def __str__(self):
-        func, arg = self._descriptors()
+        func = self._descriptor()
         if hasattr(func, 'compat_func_name'):
             name = func.compat_func_name
         else:
             name = func.__name__
         name = "%s.%s" % (func.__module__, name)
-        if arg:
-            name = "%s%s" % (name, arg)
+        if not self.arg_repr == '()':
+            name = "%s%s" % (name, self.arg_repr)
         # FIXME need to include the full dir path to disambiguate
         # in cases where test module of the same name was seen in
         # another directory (old fromDirectory)
         return name
     __repr__ = __str__
 
-    def _descriptors(self):
-        """Get the descriptors of the test function: the function and
-        arguments that will be used to construct the test name. In
-        most cases, this is the function itself and no arguments. For
-        tests generated by generator functions, the original
-        (generator) function and args passed to the generated function
-        are returned.
+    def _descriptor(self):
+        """Get the descriptor of the test method.
+
+        If a `descriptor` was specified for __init__, then it is returned, else
+        the test method (callable object) is returned.
         """
-        if self.descriptor:
-            return self.descriptor, self.arg
-        else:
-            return self.test, self.arg
+        return self.descriptor if self.descriptor is not None else self.test
 
 
 class MethodTestCase(TestBase):
@@ -338,6 +334,7 @@ def __init__(self, method, test=None, arg=tuple(), descriptor=None):
         self.method = method
         self.test = test
         self.arg = arg
+        self.arg_repr = repr(self.arg)
         self.descriptor = descriptor
         if isfunction(method):
             raise ValueError("Unbound methods must be wrapped using pyversion.unbound_method before passing to MethodTestCase")
@@ -349,16 +346,16 @@ def __init__(self, method, test=None, arg=tuple(), descriptor=None):
         TestBase.__init__(self)
 
     def __str__(self):
-        func, arg = self._descriptors()
+        func = self._descriptor()
         if hasattr(func, 'compat_func_name'):
             name = func.compat_func_name
         else:
             name = func.__name__
         name = "%s.%s.%s" % (self.cls.__module__,
                              self.cls.__name__,
                              name)
-        if arg:
-            name = "%s%s" % (name, arg)
+        if not self.arg_repr == '()':
+            name = "%s%s" % (name, self.arg_repr)
         return name
     __repr__ = __str__
 
@@ -383,15 +380,10 @@ def setUp(self):
     def tearDown(self):
         try_run(self.inst, ('teardown', 'tearDown'))
 
-    def _descriptors(self):
-        """Get the descriptors of the test method: the method and
-        arguments that will be used to construct the test name. In
-        most cases, this is the method itself and no arguments. For
-        tests generated by generator methods, the original
-        (generator) method and args passed to the generated method 
-        or function are returned.
+    def _descriptor(self):
+        """Get the descriptor of the test method.
+
+        If a `descriptor` was specified for __init__, then it is returned, else
+        the test method (callable object) is returned.
         """
-        if self.descriptor:
-            return self.descriptor, self.arg
-        else:
-            return self.method, self.arg
+        return self.descriptor if self.descriptor is not None else self.method

unit_tests/test_cases.py

@@ -115,6 +115,46 @@ def test_failure_case(self):
         f(res)
         assert res.errors
 
+    def test_FunctionTestCase_repr_is_consistent_with_mutable_args(self):
+        class Foo(object):
+            def __init__(self):
+                self.bar = 'unmodified'
+            def __repr__(self):
+                return "Foo(%s)" % self.bar
+
+        def test_foo(foo):
+            pass
+
+        foo = Foo()
+        case = nose.case.FunctionTestCase(test_foo, arg=(foo,))
+        case_repr_before = case.__repr__()
+        foo.bar = "snafu'd!"
+        case_repr_after = case.__repr__()
+        assert case_repr_before == case_repr_after, (
+            "Modifying a mutable object arg during test case changed the test "
+            "case's __repr__")
+
+    def test_MethodTestCase_repr_is_consistent_with_mutable_args(self):
+        class Foo(object):
+            def __init__(self):
+                self.bar = 'unmodified'
+            def __repr__(self):
+                return "Foo(%s)" % self.bar
+
+        class FooTester(object):
+            def test_foo(self, foo):
+                pass
+
+        foo = Foo()
+        case = nose.case.FunctionTestCase(
+            unbound_method(FooTester, FooTester.test_foo), arg=(foo,))
+        case_repr_before = case.__repr__()
+        foo.bar = "snafu'd!"
+        case_repr_after = case.__repr__()
+        assert case_repr_before == case_repr_after, (
+            "Modifying a mutable object arg during test case changed the test "
+            "case's __repr__")
+
 
 class TestNoseTestWrapper(unittest.TestCase):
     def test_case_fixtures_called(self):