Another small API break - sorry. Fixture.getDetails no longer returns the

internal details dict (self._details). Access that directly if needed. It now
looks for details in used fixtures and returns those as well as details added
directly.
(RobertCollins, #780806)

4 files changed, 58 insertions, 7 deletions

diff --git a/NEWS b/NEWS
index e0a17ec..54c4511 100644
--- a/NEWS
+++ b/NEWS
@@ -6,6 +6,11 @@ fixtures release notes
 IN DEVELOPMENT
 ~~~~~~~~~~~~~~
 
+Another small API break - sorry. Fixture.getDetails no longer returns the
+internal details dict (self._details). Access that directly if needed. It now
+looks for details in used fixtures and returns those as well as details added
+directly.
+
 CHANGES:
 
 * Details from child fixtures for both Fixture and TestWithFixtures no longer
@@ -13,6 +18,9 @@ CHANGES:
   gather_details helper).
   (Gavin Panella, #796253)
 
+* Fixture.getDetails will now return all the details of fixtures added using
+  useFixture. (RobertCollins, #780806)
+
 * New fixture ``PackagePathEntry`` which patches the path of an existing
   package, allowing importing part of it from aonther directory.
   (Robert Collins)
diff --git a/lib/fixtures/fixture.py b/lib/fixtures/fixture.py
index c42bc44..14da061 100644
--- a/lib/fixtures/fixture.py
+++ b/lib/fixtures/fixture.py
@@ -20,6 +20,7 @@ __all__ = [
     'MultipleExceptions',
     ]
 
+import itertools
 import sys
 
 from testtools.helpers import try_import
@@ -32,6 +33,17 @@ MultipleExceptions = try_import(
 
 gather_details = try_import("testtools.testcase.gather_details")
 
+# This would be better in testtools (or a common library)
+def combine_details(source_details, target_details):
+    """Add every value from source to target deduping common keys."""
+    for name, content_object in source_details.items():
+        new_name = name
+        disambiguator = itertools.count(1)
+        while new_name in target_details:
+            new_name = '%s-%d' % (name, advance_iterator(disambiguator))
+        name = new_name
+        target_details[name] = content_object
+
 
 class Fixture(object):
     """A Fixture representing some state or resource.
@@ -120,6 +132,7 @@ class Fixture(object):
         """
         self._cleanups = []
         self._details = {}
+        self._detail_sources = []
 
     def __enter__(self):
         self.setUp()
@@ -132,12 +145,15 @@ class Fixture(object):
     def getDetails(self):
         """Get the current details registered with the fixture.
 
-        This returns the internal dictionary: mutating it is supported (but not
-        encouraged).
+        This does not return the internal dictionary: mutating it will have no
+        effect. If you need to mutate it, just do so directly.
         
         :return: Dict from name -> content_object.
         """
-        return self._details
+        result = dict(self._details)
+        for source in self._detail_sources:
+            combine_details(source.getDetails(), result)
+        return result
 
     def setUp(self):
         """Prepare the Fixture for use.
@@ -180,13 +196,16 @@ class Fixture(object):
         try:
             fixture.setUp()
         except:
+            # The child failed to come up, capture any details it has (copying
+            # the content, it may go away anytime).
             if gather_details is not None:
                 gather_details(fixture, self)
             raise
         else:
             self.addCleanup(fixture.cleanUp)
-            if gather_details is not None:
-                self.addCleanup(gather_details, fixture, self)
+            # Calls to getDetails while this fixture is setup will return
+            # details from the child fixture.
+            self._detail_sources.append(fixture)
             return fixture
 
 
diff --git a/lib/fixtures/testcase.py b/lib/fixtures/testcase.py
index 38fc4ff..0a6bb61 100644
--- a/lib/fixtures/testcase.py
+++ b/lib/fixtures/testcase.py
@@ -44,10 +44,14 @@ class TestWithFixtures(unittest.TestCase):
             fixture.setUp()
         except:
             if use_details:
+                # Capture the details now, in case the fixture goes away.
                 gather_details(fixture, self)
             raise
         else:
             self.addCleanup(fixture.cleanUp)
             if use_details:
+                # Capture the details from the fixture during test teardown;
+                # this will evaluate the details before tearing down the
+                # fixture.
                 self.addCleanup(gather_details, fixture, self)
             return fixture
diff --git a/lib/fixtures/tests/test_fixture.py b/lib/fixtures/tests/test_fixture.py
index 28afe75..ed4edf0 100644
--- a/lib/fixtures/tests/test_fixture.py
+++ b/lib/fixtures/tests/test_fixture.py
@@ -25,6 +25,10 @@ from fixtures.fixture import gather_details
 from fixtures.tests.helpers import LoggingFixture
 
 
+require_gather_details = skipIf(gather_details is None,
+        "gather_details() is not available.")
+
+
 class TestFixture(testtools.TestCase):
 
     def test_resetCallsSetUpCleanUp(self):
@@ -114,7 +118,7 @@ class TestFixture(testtools.TestCase):
             ['setUp-outer', 'setUp-inner', 'cleanUp-inner', 'cleanUp-outer'],
             parent.calls)
 
-    @skipIf(gather_details is None, "gather_details() is not available.")
+    @require_gather_details
     def test_useFixture_details_captured_from_setUp(self):
         # Details added during fixture set-up are gathered even if setUp()
         # fails with an exception.
@@ -143,12 +147,28 @@ class TestFixture(testtools.TestCase):
         with fixture:
             self.assertEqual({}, fixture.getDetails())
 
+    def test_details_from_child_fixtures_are_returned(self):
+        parent = fixtures.Fixture()
+        with parent:
+            child = fixtures.Fixture()
+            parent.useFixture(child)
+            # Note that we add the detail *after* using the fixture: the parent
+            # has to query just-in-time.
+            child.addDetail('foo', 'content')
+            self.assertEqual({'foo': 'content'}, parent.getDetails())
+            # And dropping it from the child drops it from the parent.
+            del child._details['foo']
+            self.assertEqual({}, parent.getDetails())
+            # After cleanup the child details are still gone.
+            child.addDetail('foo', 'content')
+        self.assertEqual({}, parent.getDetails())
+
     def test_addDetail(self):
         fixture = fixtures.Fixture()
         with fixture:
             fixture.addDetail('foo', 'content')
             self.assertEqual({'foo': 'content'}, fixture.getDetails())
-            del fixture.getDetails()['foo']
+            del fixture._details['foo']
             self.assertEqual({}, fixture.getDetails())
             fixture.addDetail('foo', 'content')
         # Cleanup clears the details too.