Update code to reset() resources if they have been used by a test.

3 files changed, 81 insertions, 34 deletions

diff --git a/lib/testresources/__init__.py b/lib/testresources/__init__.py
index 01b407e..2fec2c0 100644
--- a/lib/testresources/__init__.py
+++ b/lib/testresources/__init__.py
@@ -196,6 +196,7 @@ class TestResource(object):
 
     def __init__(self):
         self._dirty = False
+        self._needsReset = False
         self._uses = 0
         self._currentResource = None
         self.resources = list(getattr(self.__class__, "resources", []))
@@ -232,8 +233,6 @@ class TestResource(object):
         if self._uses == 0:
             self.clean_all(resource)
             self._setResource(None)
-        else:
-            self._setResource(self.reset(resource))
 
     def getResource(self):
         """Get the resource for this class and record that it's being used.
@@ -245,11 +244,21 @@ class TestResource(object):
         """
         if self._uses == 0:
             self._setResource(self.make_all())
-        else:
+        elif self._needsReset:
             self._setResource(self.reset(self._currentResource))
         self._uses += 1
         return self._currentResource
 
+    def markUsed(self, resource):
+        """Mark the resource as having been used.
+
+        A used resource must be reset before it is used again.
+        """
+        if not self._needsReset:
+            self._needsReset = True
+            for name, manager in self.resources:
+                manager.markUsed(getattr(resource, name))
+
     def make_all(self):
         """Make the dependencies of this resource and this resource."""
         dependency_resources = {}
@@ -304,6 +313,7 @@ class TestResource(object):
         """Set the current resource to a new value."""
         self._currentResource = new_resource
         self._dirty = False
+        self._needsReset = False
 
 
 class ResourcedTestCase(unittest.TestCase):
@@ -324,6 +334,8 @@ class ResourcedTestCase(unittest.TestCase):
         """Set up any resources that this test needs."""
         for resource in self.resources:
             setattr(self, resource[0], resource[1].getResource())
+        for resource in self.resources:
+            resource[1].markUsed(getattr(self, resource[0]))
 
     def tearDown(self):
         self.tearDownResources()
diff --git a/lib/testresources/tests/test_resourced_test_case.py b/lib/testresources/tests/test_resourced_test_case.py
index 73fffac..461cacb 100644
--- a/lib/testresources/tests/test_resourced_test_case.py
+++ b/lib/testresources/tests/test_resourced_test_case.py
@@ -86,6 +86,12 @@ class TestResourcedTestCase(testtools.TestCase):
         self.resourced_case.setUpResources()
         self.assertEqual(self.resource_manager._uses, 1)
 
+    def testSetUpResourcesMarksUsed(self):
+        # resources used by a test need resetting afterwards.
+        self.resourced_case.resources = [("foo", self.resource_manager)]
+        self.resourced_case.setUpResources()
+        self.assertEqual(self.resource_manager._needsReset, True)
+
     def testTearDownResourcesDeletesResourceAttributes(self):
         self.resourced_case.resources = [("foo", self.resource_manager)]
         self.resourced_case.setUpResources()
diff --git a/lib/testresources/tests/test_test_resource.py b/lib/testresources/tests/test_test_resource.py
index 88a0634..7c1a146 100644
--- a/lib/testresources/tests/test_test_resource.py
+++ b/lib/testresources/tests/test_test_resource.py
@@ -69,6 +69,10 @@ class TestTestResource(testtools.TestCase):
         resource_manager = testresources.TestResource()
         self.assertEqual(False, resource_manager._dirty)
 
+    def testInitiallyNotNeedsReset(self):
+        resource_manager = testresources.TestResource()
+        self.assertEqual(False, resource_manager._needsReset)
+
     def testInitiallyUnused(self):
         resource_manager = testresources.TestResource()
         self.assertEqual(0, resource_manager._uses)
@@ -148,6 +152,16 @@ class TestTestResource(testtools.TestCase):
         resource_manager.getResource()
         self.assertEqual(1, resource_manager.makes)
 
+    def testGetResourceResetsUsedResource(self):
+        resource_manager = MockResettableResource()
+        resource_manager.getResource()
+        resource = resource_manager.getResource()
+        self.assertEqual(1, resource_manager.makes)
+        resource_manager.markUsed(resource)
+        resource_manager.getResource()
+        self.assertEqual(1, resource_manager.makes)
+        self.assertEqual(1, resource_manager.resets)
+
     def testFinishedWithDecrementsUses(self):
         resource_manager = MockResource()
         resource = resource_manager.getResource()
@@ -195,6 +209,13 @@ class TestTestResource(testtools.TestCase):
         resource_manager.finishedWith(resource)
         self.assertEqual(False, resource_manager._dirty)
 
+    def testFinishedWithMarksNeedsReset(self):
+        resource_manager = MockResource()
+        resource = resource_manager.getResource()
+        resource_manager.markUsed(resource)
+        resource_manager.finishedWith(resource)
+        self.assertEqual(False, resource_manager._needsReset)
+
     def testResourceAvailableBetweenFinishedWithCalls(self):
         resource_manager = MockResource()
         resource = resource_manager.getResource()
@@ -202,6 +223,30 @@ class TestTestResource(testtools.TestCase):
         resource_manager.finishedWith(resource)
         self.assertIs(resource, resource_manager._currentResource)
 
+    def testMarkUsedSetsNeedsReset(self):
+        resource_manager = MockResettableResource()
+        resource = resource_manager.getResource()
+        self.assertEqual(False, resource_manager._needsReset)
+        resource_manager.markUsed(resource)
+        self.assertEqual(True, resource_manager._needsReset)
+
+    def testUsedResourceResetBetweenUses(self):
+        resource_manager = MockResettableResource()
+        resource_manager.getResource()
+        resource = resource_manager.getResource()
+        resource_manager.markUsed(resource)
+        resource_manager.finishedWith(resource)
+        resource = resource_manager.getResource()
+        resource_manager.markUsed(resource)
+        resource_manager.finishedWith(resource)
+        resource_manager.finishedWith(resource)
+        # The resource is made once, reset once and cleaned once.
+        self.assertEqual(1, resource_manager.makes)
+        self.assertEqual(1, resource_manager.resets)
+        self.assertEqual(1, resource_manager.cleans)
+
+    # The default implementation of reset() performs a make/clean if
+    # the dirty flag is set.
     def testDirtiedSetsDirty(self):
         resource_manager = MockResource()
         resource = resource_manager.getResource()
@@ -209,25 +254,23 @@ class TestTestResource(testtools.TestCase):
         resource_manager.dirtied(resource)
         self.assertEqual(True, resource_manager._dirty)
 
-    def testDirtyingResourceTriggersClean(self):
+    def testDefaultResetMethodPreservesCleanResource(self):
         resource_manager = MockResource()
-        resource1 = resource_manager.getResource()
-        resource2 = resource_manager.getResource()
-        resource_manager.dirtied(resource2)
-        resource_manager.finishedWith(resource2)
-        self.assertEqual(1, resource_manager.cleans)
-        resource_manager.finishedWith(resource1)
-        self.assertEqual(2, resource_manager.cleans)
+        resource = resource_manager.getResource()
+        self.assertEqual(1, resource_manager.makes)
+        self.assertEqual(False, resource_manager._dirty)
+        resource_manager.reset(resource)
+        self.assertEqual(1, resource_manager.makes)
+        self.assertEqual(0, resource_manager.cleans)
 
-    def testDirtyingResourceTriggersRemake(self):
+    def testDefaultResetMethodRecreatesDirtyResource(self):
         resource_manager = MockResource()
         resource = resource_manager.getResource()
         self.assertEqual(1, resource_manager.makes)
         resource_manager.dirtied(resource)
-        resource_manager.getResource()
-        self.assertEqual(1, resource_manager.cleans)
+        resource_manager.reset(resource)
         self.assertEqual(2, resource_manager.makes)
-        self.assertEqual(False, resource_manager._dirty)
+        self.assertEqual(1, resource_manager.cleans)
 
     def testDirtyingWhenUnused(self):
         resource_manager = MockResource()
@@ -238,25 +281,11 @@ class TestTestResource(testtools.TestCase):
         resource = resource_manager.getResource()
         self.assertEqual(2, resource_manager.makes)
 
-    def testGetResourceResetsResource(self):
-        resource_manager = MockResettableResource()
-        resource = resource_manager.getResource()
-        self.assertEqual(1, resource_manager.makes)
-        resource = resource_manager.getResource()
-        self.assertEqual(1, resource_manager.makes)
-        self.assertEqual(1, resource_manager.resets)
-
-    def testFinishedWithResetsResource(self):
-        resource_manager = MockResettableResource()
+    def testMarkUsedWhenUnused(self):
+        resource_manager = MockResource()
         resource = resource_manager.getResource()
+        resource_manager.finishedWith(resource)
+        resource_manager.markUsed(resource)
         self.assertEqual(1, resource_manager.makes)
         resource = resource_manager.getResource()
-        self.assertEqual(1, resource_manager.makes)
-        self.assertEqual(1, resource_manager.resets)
-
-        resource_manager.finishedWith(resource)
-        self.assertEqual(2, resource_manager.resets)
-        self.assertEqual(0, resource_manager.cleans)
-        resource_manager.finishedWith(resource)
-        self.assertEqual(2, resource_manager.resets)
-        self.assertEqual(1, resource_manager.cleans)
+        self.assertEqual(2, resource_manager.makes)