Rev 5580: Test tests.DocTestSuite, using doctest.DocTestSuite as a reference point. in file:///home/vila/src/bzr/bugs/test-isolation/

[Vincent Ladeuil]

At file:///home/vila/src/bzr/bugs/test-isolation/

------------------------------------------------------------
revno: 5580
revision-id: v.ladeuil+lp at free.fr-20101218152154-1iav50e5udef6tjt
parent: v.ladeuil+lp at free.fr-20101218124315-mvi2ohaixgtk1o6o
committer: Vincent Ladeuil <v.ladeuil+lp at free.fr>
branch nick: even-better-isolation
timestamp: Sat 2010-12-18 16:21:54 +0100
message:
  Test tests.DocTestSuite, using doctest.DocTestSuite as a reference point.
-------------- next part --------------
=== modified file 'bzrlib/tests/__init__.py'
--- a/bzrlib/tests/__init__.py	2010-12-18 12:43:15 +0000
+++ b/bzrlib/tests/__init__.py	2010-12-18 15:21:54 +0000
@@ -887,8 +887,8 @@
 
     The method is really a factory and users are expected to use it as such.
     """
-#    kwargs['setUp'] = override_os_environ
-#    kwargs['tearDown'] = restore_os_environ
+    kwargs['setUp'] = override_os_environ
+    kwargs['tearDown'] = restore_os_environ
     return doctest.DocTestSuite(*args, **kwargs)
 
 

=== modified file 'bzrlib/tests/test_selftest.py'
--- a/bzrlib/tests/test_selftest.py	2010-12-18 12:43:15 +0000
+++ b/bzrlib/tests/test_selftest.py	2010-12-18 15:21:54 +0000
@@ -3511,8 +3511,19 @@
 
 
 class TestDocTestSuiteIsolation(tests.TestCase):
-
-    def get_doctest_suite(self, klass, string):
+    """Test that `tests.DocTestSuite` isolates doc tests from os.environ.
+
+    Since tests.TestCase alreay provides an isolation from os.environ, we use
+    the clean environment as a base for testing. To precisely capture the
+    isolation provided by tests.DocTestSuite, we use doctest.DocTestSuite to
+    compare against.
+
+    We want to make sure `tests.DocTestSuite` respect `tests.isolated_environ`,
+    not `os.environ` so each test overrides it to suit its needs.
+
+    """
+
+    def get_doctest_suite_for_string(self, klass, string):
         class Finder(doctest.DocTestFinder):
 
             def find(*args, **kwargs):
@@ -3523,23 +3534,42 @@
         suite = klass(test_finder=Finder())
         return suite
 
+    def run_doctest_suite_for_string(self, klass, string):
+        suite = self.get_doctest_suite_for_string(klass, string)
+        output = StringIO()
+        result = tests.TextTestResult(output, 0, 1)
+        suite.run(result)
+        return result, output
+
     def assertDocTestStringSucceds(self, klass, string):
-        suite = self.get_doctest_suite(klass, string)
-        output = StringIO()
-        result = tests.TextTestResult(output, 0, 1)
-        suite.run(result)
+        result, output = self.run_doctest_suite_for_string(klass, string)
         if not result.wasStrictlySuccessful():
             self.fail(output.getvalue())
 
+    def assertDocTestStringFails(self, klass, string):
+        result, output = self.run_doctest_suite_for_string(klass, string)
+        if result.wasStrictlySuccessful():
+            self.fail(output.getvalue())
+
     def test_injected_variable(self):
-        self.assertDocTestStringSucceds(tests.DocTestSuite, """
+        self.overrideAttr(tests, 'isolated_environ', {'LINES': '42'})
+        test = """
             >>> import os
             >>> os.environ['LINES']
-            '25'
-            """)
+            '42'
+            """
+        # doctest.DocTestSuite fails as it sees '25'
+        self.assertDocTestStringFails(doctest.DocTestSuite, test)
+        # tests.DocTestSuite sees '42'
+        self.assertDocTestStringSucceds(tests.DocTestSuite, test)
 
     def test_deleted_variable(self):
-        self.assertDocTestStringSucceds(tests.DocTestSuite, """
+        self.overrideAttr(tests, 'isolated_environ', {'LINES': None})
+        test = """
             >>> import os
-            >>> os.environ.get('BZR_HOME')
-            """)
+            >>> os.environ.get('LINES')
+            """
+        # doctest.DocTestSuite fails as it sees '25'
+        self.assertDocTestStringFails(doctest.DocTestSuite, test)
+        # tests.DocTestSuite sees None
+        self.assertDocTestStringSucceds(tests.DocTestSuite, test)