Become compatible with newer Fixtures _setUp() API.

Previously, when gathering details caused by a setUp failure,
a traceback occurred if the fixture used the newer _setUp().
This also had the side effect of not clearing up fixtures properly.

Change-Id: I9d138e8d559e176867c6e3f4b89f784cf4d29f05
Fixes: https://bugs.launchpad.net/testtools/+bug/1469759

LICENSE

@@ -19,6 +19,7 @@ The testtools authors are:
  * Vincent Ladeuil
  * Nikola Đipanov
  * Tristan Seligmann
+ * Julian Edwards
 
 and are collectively referred to as "testtools developers".
 

NEWS

@@ -21,6 +21,10 @@ Improvements
   report the lack of result as a test error. This ought to make weird
   concurrency interaction bugs easier to understand. (Jonathan Lange)
 
+* Previously, when gathering details caused by a setUp() failure,
+  a traceback occurred if the fixture used the newer _setUp().
+  This had the side effect of not clearing up fixtures nor gathering details
+  properly.  This is now fixed. (Julian Edwards, #1469759)
 
 2.0.0
 ~~~~~

testtools/testcase.py

@@ -26,6 +26,7 @@ from extras import (
     try_import,
     try_imports,
     )
+fixtures = try_import('fixtures')
 # To let setup.py work, make this a conditional import.
 unittest = try_imports(['unittest2', 'unittest'])
 
@@ -49,7 +50,10 @@ from testtools.matchers import (
     )
 from testtools.matchers._basic import _FlippedEquals
 from testtools.monkey import patch
-from testtools.runtest import RunTest
+from testtools.runtest import (
+    MultipleExceptions,
+    RunTest,
+    )
 from testtools.testresult import (
     ExtendedToOriginalDecorator,
     TestResult,
@@ -680,10 +684,22 @@ class TestCase(unittest.TestCase):
         """
         try:
             fixture.setUp()
+        except MultipleExceptions as e:
+            if (fixtures is not None and
+                    e.args[-1][0] is fixtures.fixture.SetupError):
+                gather_details(e.args[-1][1].args[0], self.getDetails())
+            raise
         except:
             exc_info = sys.exc_info()
             try:
-                gather_details(fixture.getDetails(), self.getDetails())
+                # fixture._details is not available if using the newer
+                # _setUp() API in Fixtures because it already cleaned up
+                # the fixture.  Ideally this whole try/except is not
+                # really needed any more, however, we keep this code to
+                # remain compatible with the older setUp().
+                if (safe_hasattr(fixture, '_details') and
+                        fixture._details is not None):
+                    gather_details(fixture.getDetails(), self.getDetails())
             except:
                 # Report the setUp exception, then raise the error during
                 # gather_details.

testtools/tests/test_fixturesupport.py

@@ -10,7 +10,10 @@ from testtools import (
     content_type,
     )
 from testtools.compat import _b, _u
-from testtools.matchers import Contains
+from testtools.matchers import (
+    Contains,
+    Equals,
+    )
 from testtools.testresult.doubles import (
     ExtendedTestResult,
     )
@@ -18,7 +21,6 @@ from testtools.testresult.doubles import (
 fixtures = try_import('fixtures')
 LoggingFixture = try_import('fixtures.tests.helpers.LoggingFixture')
 
-
 class TestFixtureSupport(TestCase):
 
     def setUp(self):
@@ -113,6 +115,40 @@ class TestFixtureSupport(TestCase):
         self.assertEqual(['content', 'traceback'], sorted(details))
         self.assertEqual('foobar', ''.join(details['content'].iter_text()))
 
+    def test_useFixture_details_captured_from__setUp(self):
+        # Newer Fixtures deprecates setUp() in favour of _setUp().
+        # https://bugs.launchpad.net/testtools/+bug/1469759 reports that
+        # this is broken when gathering details from a broken _setUp().
+        class BrokenFixture(fixtures.Fixture):
+            def _setUp(self):
+                fixtures.Fixture._setUp(self)
+                self.addDetail('broken', content.text_content("foobar"))
+                raise Exception("_setUp broke")
+        fixture = BrokenFixture()
+        class SimpleTest(TestCase):
+            def test_foo(self):
+                self.addDetail('foo_content', content.text_content("foo ok"))
+                self.useFixture(fixture)
+        result = ExtendedTestResult()
+        SimpleTest('test_foo').run(result)
+        self.assertEqual('addError', result._events[-2][0])
+        details = result._events[-2][2]
+        self.assertEqual(
+            ['broken', 'foo_content', 'traceback', 'traceback-1'],
+            sorted(details))
+        self.expectThat(
+            ''.join(details['broken'].iter_text()),
+            Equals('foobar'))
+        self.expectThat(
+            ''.join(details['foo_content'].iter_text()),
+            Equals('foo ok'))
+        self.expectThat(
+            ''.join(details['traceback'].iter_text()),
+            Contains('_setUp broke'))
+        self.expectThat(
+            ''.join(details['traceback-1'].iter_text()),
+            Contains('foobar'))
+
     def test_useFixture_original_exception_raised_if_gather_details_fails(self):
         # In bug #1368440 it was reported that when a fixture fails setUp
         # and gather_details errors on it, then the original exception that